tag:blogger.com,1999:blog-86953069810034959022024-03-18T09:17:23.115-05:00The Manure ScoopThe science of manure, including its management and handling, options for treatment, use as fertilizer, the impact it can have on the environment, and new technologies being developed to improve its use. In this blog I strive to provide a scientific perspective and really dig into the issues. This blog is brought to you by Iowa State University Extension and Outreach. Follow me on Twitter @DrManure or find me on Facebook at Iowa State Manure and Nutrient Management Lab.Daniel Andersenhttp://www.blogger.com/profile/17296164974381593950noreply@blogger.comBlogger110125tag:blogger.com,1999:blog-8695306981003495902.post-73492950322370944352024-01-25T13:02:00.002-06:002024-01-25T13:02:16.340-06:00Optimizing Anaerobic Digestion Efficiency: Calculating Biogas Potential<p> </p><p class="MsoNormal"><o:p> </o:p><i><span style="color: #0e101a;">Introduction:</span></i></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><i style="mso-bidi-font-style: normal;"><span style="color: #0e101a;"><o:p> </o:p></span></i></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">Anaerobic
digestion is a process that harnesses the power of microorganisms to break down
organic materials without oxygen, producing biogas as a valuable byproduct. This
process has gained significant attention as a means to manage organic waste and
generate renewable energy. This blog will delve into the intricacies of
optimizing anaerobic digestion efficiency, focusing on factors influencing
different digester types and substrates – specifically, livestock manures and
crop residues.<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;"><o:p> </o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><em><span style="color: #0e101a;">Factors
Influencing Anaerobic Digestion Efficiency:<o:p></o:p></span></em></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;"><o:p> </o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">Temperature
and pH:<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">Anaerobic
digestion is a temperature-sensitive process with optimal efficiency and
stability within specific temperature ranges. Additionally, maintaining an
appropriate pH level is crucial for the activity of microorganisms involved in
digestion. Different digester types may require adjustments in temperature and
pH to maximize efficiency. Generally, designed heated digesters for agriculture
are maintained at around 95-100ºF. As a general rule of thumb, microbial
activity doubles for every 20ºF, so heating a digester allows significantly
shorter retention times. While heating above 100ºF can further increase
reaction rates, it also makes the process less stable as different bacteria and
archaea populations respond differently to temperature.<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;"><o:p> </o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">Retention
Time:<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">The
duration for which organic materials are retained in the digester, known as
retention time, plays a vital role in achieving optimal biogas production.
Longer retention times generally lead to higher gas yields, but striking the
right balance is essential to prevent process inhibition and to balance the
initial cost of the digester against the potential yield for the substrate. For
example, holding materials for an additional 30 days to make 5% more methane
often can’t be justified.<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;"><o:p> </o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">Substrate
Characteristics:<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">The
type and composition of substrates significantly impact anaerobic digestion
efficiency. Livestock manures, such as those from cattle, poultry, and swine,
vary in nutrient content and organic composition. Crop residues,
including straw and stalks, also introduce diverse characteristics to the
digestion process. Understanding these variations is crucial for efficient
biogas production and material handling considerations. Different tests,
biochemical methane potential, and anaerobic toxicity assays are often used to
characterize how desirable different substrates may be and if there could be
issues with inhibition from chemical compounds. Physical properties are often
characterized for solids content and particle size, with viscosity and settling
rate sometimes characterized.<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;"><o:p> </o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><em><span style="color: #0e101a;">Digester
Types and Their Influence:<o:p></o:p></span></em></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;"><o:p> </o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">Batch
Digesters:<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">Batch
digesters are characterized by loading organic materials in batches and
allowing them to ferment for a specific period. These digesters are suitable
for smaller-scale operations and can handle various substrates. However,
optimizing efficiency in batch digesters requires careful consideration of
loading frequency and substrate characteristics. In practice, few of these
digesters exist, though more use has been seen with “high-solids” digestion.<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;"><o:p> </o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">Continuous
Stirred-Tank Reactors (CSTR):<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">CSTRs
maintain a constant flow of organic material into the digester, ensuring a
continuous process. These systems are efficient for managing large quantities
of waste. Factors such as temperature control, stirring mechanisms, and
substrate consistency play key roles in optimizing CSTR performance.<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;"><o:p> </o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">Plug
Flow Digesters:<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">Plug-flow
digesters facilitate a unidirectional flow of organic material through the
digester, promoting better mixing and higher gas yields. Achieving optimal
performance in plug flow digesters involves careful design considerations and
monitoring of substrate characteristics. Essentially, it needs a high enough
solids content to act as a plug but not so high that it won’t flow through the
digester.<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;"><o:p> </o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><em><span style="color: #0e101a;">Substrates:
Livestock Manures and Crop Residues:<o:p></o:p></span></em></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;"><o:p> </o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">Livestock
Manures:<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">Different
livestock manures present unique challenges and opportunities for anaerobic
digestion. Cattle manure, for instance, is rich in volatile solids, while
poultry manure has a higher nitrogen content. Understanding the nutrient
profiles of various manures is essential for tailoring digester conditions and
maximizing biogas potential. In general, liquid manures are often preferred as
little modification is needed to make them amenable to use in a digester. Many
manures have higher nitrogen contents, which can make ammonia toxicity a
potential concern.<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;"><o:p> </o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">Crop
Residues:<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">Crop
residues, such as straw and stalks, contribute to the diversity of anaerobic
digestion substrates. These materials often have a higher lignocellulosic
content, requiring special attention to enhance breakdown and gas production.
Exploring pre-treatment methods can improve the digestibility of crop residues
in anaerobic digesters. Particle size and maceration considerations, as well as
the overall moisture content of the mix, are important to make these materials
function in a digester.<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;"><o:p> </o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><em><span style="color: #0e101a;">Simple
Calculation for Estimating Biogas Production:</span></em><span style="color: #0e101a;"><o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;"><o:p> </o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">A
simple calculation for estimating methane production is based on the volatile
solids content (VS), biochemical methane yield potential (BMP), and digester
efficiency. The formula for biogas production (BP) is given by:<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">BP=VS×BMP×DE<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;"><o:p> </o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">Where:<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">VS is
the volatile solids content of the substrate.<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">BP is
the methane yield potential, representing the volume of methane produced per
unit of volatile solids.<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">DE is
the digester efficiency, accounting for the proportion of methane produced
compared to the maximum potential.<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;"><o:p> </o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">The
complicating factor is getting good values for each of these parameters. The
volatile solids and BMP vary based on diet, manure holding time, weather conditions,
and other factors, making estimating for a specific farm difficult.<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;"><o:p> </o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">For
lagoons, this can be complicated, as the temperatures and storage times vary
regionally. In the figure below, the blue color represents lagoon digester
efficiency if a yearly retention time is used, the red if manure is applied
twice per year, and the purple the loss of efficacy from more frequent manure
removal. Estimated lagoon efficacies reported in the EPA Ag Star database are
provided to the right of the figure. Green dots represent states where
reporting lagoon digesters are located (the majority in California). Heated
digester efficiency is generally closer to 75%, with temperature, substrate,
and retention time all impacting reported efficiency.<o:p></o:p></span></p>
<div><br /></div><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjiQtWABWVHaa4qZGPvhp9KLXijq93qMX4og71CvKfpz_gxy_OVoZkSH5Wk0y4AYalfLVx65NN_trCyUjSPl069_DItoO8wZYGcvLwyy7gzJVWf0fldf53b32vUopmJtFHM5VUZeDGs1Q4rDOMbRB8yFz2Cfx4Vfo4x6hFsgownx26SuPCqV7wG_pEhxZ0/s1126/USMap.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em; text-align: center;"><img border="0" data-original-height="658" data-original-width="1126" height="358" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjiQtWABWVHaa4qZGPvhp9KLXijq93qMX4og71CvKfpz_gxy_OVoZkSH5Wk0y4AYalfLVx65NN_trCyUjSPl069_DItoO8wZYGcvLwyy7gzJVWf0fldf53b32vUopmJtFHM5VUZeDGs1Q4rDOMbRB8yFz2Cfx4Vfo4x6hFsgownx26SuPCqV7wG_pEhxZ0/w613-h358/USMap.png" width="613" /></a><br />
<p class="MsoNormal">Figure 1. Estimated lagoon efficacies for livestock manures.
Blue represents efficacy of annual application, red represents a twice a year
application strategy, and the purple represents the loss in efficiency from twice a year
application instead of annual application.<o:p></o:p></p>
<p class="MsoNormal">Conclusion:<o:p></o:p></p>
<p class="MsoNormal">Optimizing anaerobic digestion efficiency is a
multidimensional task that requires careful consideration of factors
influencing both digester performance and substrate characteristics. By
understanding the nuances of different digester types and the diverse nature of
livestock manures and crop residues, we can pave the way for sustainable waste
management and renewable energy production. The future of anaerobic digestion
lies in the synergy between scientific understanding and practical application,
offering a promising avenue for addressing environmental challenges while
harnessing the full potential of biogas production.<o:p></o:p></p><div class="separator" style="clear: both; text-align: center;"><br /></div><br /><div class="separator" style="clear: both; text-align: center;"><br /></div><br />Daniel Andersenhttp://www.blogger.com/profile/17296164974381593950noreply@blogger.com1tag:blogger.com,1999:blog-8695306981003495902.post-62449383720590764612023-12-20T08:51:00.001-06:002023-12-20T08:51:04.062-06:00 Maximizing Efficiency: Aeration for Manure Treatment in Livestock Barns<p><br /></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;"><o:p> </o:p></span><span style="color: #0e101a;">Managing
manure is a critical aspect of modern livestock farming, and as the agriculture
industry evolves, so do the techniques for handling and treating manure. One
innovative method gaining popularity is aeration, particularly in deep pit
manure storages for swine finishing, dairy cattle, and beef barns. This article
delves into the science behind aeration, its impact on manure solids breakdown,
nutrient content, ammonia and greenhouse gas emissions, and its influence on
biological oxygen demand (BOD).</span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;"><o:p> </o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><strong><span style="color: #0e101a;">Aeration
vs. Anaerobic Decomposition:</span></strong><span style="color: #0e101a;"><o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">Traditionally,
liquid manure management has relied on anaerobic decomposition, which occurs
without oxygen. While this method is effective, it focuses most effort on
storage, especially for deep pit facilities, with anaerobic decomposition
occurring as a side effect of organic matter in the manure being held. In
anaerobic situations, organic carbon molecules break down in cascading
reactions towards carbon dioxide and methane. However, as little energy is
released in these reactions, reaction rates are typically slower and can result
in the loss of some partially degraded organic compounds that result in odor.
Similarly, as these reactions are low energy they often are slow, which can
mean slower solids decomposition.<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">Aeration
introduces oxygen into the manure, fostering an aerobic environment. Aerobic
reactions release more energy and, as a result, encourage greater microbial
activity and faster reaction rates. Because reaction rates are faster, the
breakdown of solids is encouraged. Carbon processing in aerobic conditions
flows from organic carbon towards carbon dioxide, and while it is again a
series of cascading reactions, the higher microbial activity limits the
accumulation of carbon breakdown products and the potential for odor emissions.<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;"><o:p> </o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><strong><span style="color: #0e101a;">Manure
Solids Breakdown:</span></strong><span style="color: #0e101a;"><o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">Why do
elephants breathe in oxygen? I'll often start a lecture this way when
discussing manure because it illustrates the concept of energy flows well. If
you want to get big you need to be making energy in the reactions. Aeration
enhances the breakdown of manure solids through microbial activity.
Microorganisms thrive in the presence of oxygen, accelerating the decomposition
process. This results in a more homogeneous and liquid manure, making it easier
to handle and apply to fields as fertilizer. However, the extent of the change
depends – on how complete was brake down under anaerobic conditions and how
complete it is under aerobic conditions. Aeration can potentially increase
solids breakdown and generally will, but the extent matters in these
conversations about what the result will be.<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">The air
flux through the manure also has the potential to suspend and mix manure solid
particles back into the manure, making it more uniform. However, limited work
has shown the impact at different air flow rates. Several years ago, experience
with foaming manure indicated that higher methane fluxes lead to more uniform
manure composition; similar impacts would be expected for aeration mixing, but
results will vary based on changes in solids content, particle size, and the
intensity the aeration mixing provides.<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;"><o:p> </o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><strong><span style="color: #0e101a;">Nutrient
Content and Availability:</span></strong><span style="color: #0e101a;"><o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">Aerobic
conditions promote the conversion of organic matter into free ions. Less
organic matter (i.e., greater solids breakdown can free nitrogen and phosphorus
making it more rapidly available in aerated manure. For phosphorus, this has
little impact on overall fertility, as the phosphorus is held reasonably well
in soil, and we can implement fertility management planning to handle
availability. For nitrogen, the answer is more complex. For a manure like
swine, where all the nitrogen is already first year, it is more immediately
available at application, but it doesn't change our ability to take advantage
of the nitrogen. With cattle manures where typically a multiyear mineralization
sequence is used, it will push more of the nitrogen being available into the
first year, where we have more opportunity to account for it and credit the
manure appropriately.<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;"><o:p> </o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><strong><span style="color: #0e101a;">Ammonia,
Odor, and Methane Emissions:</span></strong><span style="color: #0e101a;"><o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">Aeration
can either increase or decrease ammonia emissions from manure, with no clear
answer yet available, and the answer is at least somewhat dependent on the
aeration system used. Aeration provides a relatively clear decrease in odor
emissions for the reasons discussed previously. Additionally, methane emissions
are diminished under aerobic conditions – with low levels of aeration generally
as effective as methanogenesis, performing microorganisms are relatively easily
disrupted.<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;"><o:p> </o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><strong><span style="color: #0e101a;">Biological
Oxygen Demand (BOD):</span></strong><span style="color: #0e101a;"><o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">How
much oxygen or air is required? It depends – what are the goals of the aeration
system, and what are we hoping to achieve? However, in all cases, we are generally
trying to aerate based on the biological oxygen demand of the manure. The
biological oxygen demand, or biochemical oxygen demand, is the amount of
dissolved oxygen aerobic organisms need to break down organic material in a
given water sample at a certain temperature over a specific period.
Essentially, it is a measure of the wastewater, or manure strength, with higher
biological oxygen demand, meaning greater wastewater strength.<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">Historically,
the recommendation has been approximately supplying enough oxygen to satisfy
twice the biological oxygen demand in the manure. This recommendation is based
on stabilizing all decomposable organic matter in the manure and assuming
oxygen transfer efficiencies. However, low-rate (0.3-0.5x BOD) aeration has proven
successful for odor reduction and methane emission mitigation, with lower
potential benefits.<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;"><o:p> </o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><strong><span style="color: #0e101a;">Full
Rate Aeration vs. Low Rate Aeration:</span></strong><span style="color: #0e101a;"><o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">The
choice between full-rate aeration and low-rate aeration depends on various
factors, including the type of livestock, barn size, and climate conditions.
Full-rate aeration involves high airflow, facilitating rapid manure
decomposition and more complete decomposition. On the other hand, low-rate
aeration is a more energy-efficient option that may provide many benefits
(reduced odor, reduced methane emissions) while reducing energy requirements
for system operation.<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;"><o:p> </o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><strong><span style="color: #0e101a;">Example:</span></strong><span style="color: #0e101a;"><o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">The
ASABE manure production standard provides estimated BOD excretion for different
animals, with finishing cattle estimated at 1 lb BOD per day, dairy cattle at 3
lb BOD per day, and finishing swine at 0.3 lb BOD per day.<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">Looking
at swine, let's do an example where we want to supply 2X the BOD for aeration
and another at 0.3x.<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">We can
make a rough estimate of the energy needed to achieve the oxygen requirement.
While there is variation in oxygen transfer efficiencies, 3-5 lb O2/kWhr are
typical.<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">Assuming
an electrical cost of $0.10/kWhr allows operating costs to be estimated.<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;"><o:p> </o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><i style="mso-bidi-font-style: normal;"><span style="color: #0e101a;">Full Aeration<o:p></o:p></span></i></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">0.3 lb
BOD/pig- day x 2 lb O2/lb BOD = 0.6 lb O2/pig-day<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">0.6 lb
O2/pig-day / 4 lb O2/kWhr = 0.15 kWhr/pig-day<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">0.15
kWhr/pig-day x $0.10/kWhr x 365 days = $5.50 /pig space-year<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;"><o:p> </o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><i style="mso-bidi-font-style: normal;"><span style="color: #0e101a;">Partial Aeration<o:p></o:p></span></i></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">0.3 lb
BOD/pig-day x 0.3 lb O2/lb BOD = 0.09 lb O2/pig-day<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">0.6 lb
O2/pig-day / 4 lb O2/kWhr = 0.0225 kWhr/pig-day<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">0.025
kWhr/pig-day x $0.10/kWhr x 365 days = $0.82 /pig space-year<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;"><o:p> </o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">Further
work is needed to quantify the difference in potential benefits of each system
to understand how different aeration rates impact solids suspension, breakdown,
and mixing.<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><strong><span style="color: #0e101a;"><o:p> </o:p></span></strong></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><strong><span style="color: #0e101a;">Conclusion:</span></strong><span style="color: #0e101a;"><o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">Aeration
is revolutionizing manure management in livestock farming, offering a
sustainable and environmentally friendly alternative to traditional anaerobic
methods. The benefits, from improved nutrient content and availability to
reduced ammonia and greenhouse gas emissions, make it a valuable tool for
modern agriculture. Farmers should carefully assess their needs and consider
factors such as BOD levels, livestock type, and barn size when implementing
aeration systems, ultimately contributing to a more efficient and sustainable
farming future.<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;"><o:p> </o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">In next
month's article, we will use this information to size a blower system and the
airlines for an example aeration system.<o:p></o:p></span></p><p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;"><br /></span></p><p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;"></span></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/a/AVvXsEhfr2Yv8IBza3dnx6xn4OU5_u0-4nd6r8rWfD7FQ8mWQMM6zijbBhu_o_5LjxiAMxv_CQKABwAwDN8jrvn6zVh7sjFe2BtPtdQeyJbv-rnsxP3lhHrZgdlUs8xGBsqbQb7teXFpu7v8kuRnO0HJeuhsvTDkPlG3Vq3eZQ20ZvBkp-f0LfCI47kl8cttk_U" style="margin-left: 1em; margin-right: 1em;"><img alt="" data-original-height="768" data-original-width="513" height="240" src="https://blogger.googleusercontent.com/img/a/AVvXsEhfr2Yv8IBza3dnx6xn4OU5_u0-4nd6r8rWfD7FQ8mWQMM6zijbBhu_o_5LjxiAMxv_CQKABwAwDN8jrvn6zVh7sjFe2BtPtdQeyJbv-rnsxP3lhHrZgdlUs8xGBsqbQb7teXFpu7v8kuRnO0HJeuhsvTDkPlG3Vq3eZQ20ZvBkp-f0LfCI47kl8cttk_U" width="160" /></a></div><div class="separator" style="clear: both; text-align: center;">Figure 1. Aeration lines outside the barn that actuate in zones to aerate the manure.</div><br /><br /><p></p>Daniel Andersenhttp://www.blogger.com/profile/17296164974381593950noreply@blogger.com0tag:blogger.com,1999:blog-8695306981003495902.post-83981928990573820082023-11-15T13:06:00.004-06:002023-11-15T13:06:31.470-06:00Balancing Act: Carbon Flows in a Continuous Corn System with Stover Harvesting for Livestock Bedding and Manure Reapplication<p style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; color: #0e101a; margin-bottom: 0pt; margin-top: 0pt;">In the vast landscapes of modern agriculture, the intricate dance of carbon within ecosystems plays a pivotal role in sustaining soil health and fertility. One such intricate choreography unfolds in continuous corn systems where the harvest of corn stover for livestock bedding intersects with the subsequent application of stover-laden manure. Let us explore this delicate balance of carbon flows and its implications for soil health.</p><p style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; color: #0e101a; margin-bottom: 0pt; margin-top: 0pt;"><br /></p><p style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; color: #0e101a; margin-bottom: 0pt; margin-top: 0pt;"><em style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; margin-bottom: 0pt; margin-top: 0pt;">Harvest: The Carbon Exodus</em></p><p style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; color: #0e101a; margin-bottom: 0pt; margin-top: 0pt;"><em style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; margin-bottom: 0pt; margin-top: 0pt;"><br /></em></p><p style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; color: #0e101a; margin-bottom: 0pt; margin-top: 0pt;"><span data-preserver-spaces="true" style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; margin-bottom: 0pt; margin-top: 0pt;">Continuous corn systems rely on the consistent cultivation of corn year after year. In this cycle, corn stover, comprising stalks, leaves, and cobs, is a crucial component. However, the decision to harvest corn stover for livestock bedding initiates a subtle but impactful carbon exodus from the agricultural ecosystem. When corn stover is removed from the field, it takes a significant portion of organic carbon. This organic matter, a key constituent of healthy soils, contributes to soil structure, water retention, and fertility. The concern arises when this organic carbon, essential for microbial activity and nutrient cycling, is carted away, potentially leaving the soil in diminished fertility.</span></p><p style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; color: #0e101a; margin-bottom: 0pt; margin-top: 0pt;"><span data-preserver-spaces="true" style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; margin-bottom: 0pt; margin-top: 0pt;"><br /></span></p><p style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; color: #0e101a; margin-bottom: 0pt; margin-top: 0pt;"><span data-preserver-spaces="true" style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; margin-bottom: 0pt; margin-top: 0pt;">To help put some numbers to this, let us assume 200 bushels of corn, a harvest index of 0.5, and a shoot-to-root ratio of 0.21.</span></p><p style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; color: #0e101a; margin-bottom: 0pt; margin-top: 0pt;"><span data-preserver-spaces="true" style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; margin-bottom: 0pt; margin-top: 0pt;"><br /></span></p><p style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; color: #0e101a; margin-bottom: 0pt; margin-top: 0pt;"><span data-preserver-spaces="true" style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; margin-bottom: 0pt; margin-top: 0pt;">200 bu/acre x 56 lb/bu x 0.845 lb dry matter/lb grain = 9464 lb dry grain/acre</span></p><p style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; color: #0e101a; margin-bottom: 0pt; margin-top: 0pt;"><span data-preserver-spaces="true" style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; margin-bottom: 0pt; margin-top: 0pt;"><br /></span></p><p style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; color: #0e101a; margin-bottom: 0pt; margin-top: 0pt;"><span data-preserver-spaces="true" style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; margin-bottom: 0pt; margin-top: 0pt;">Using the harvest index, we can get stover produced.</span></p><p style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; color: #0e101a; margin-bottom: 0pt; margin-top: 0pt;"><span data-preserver-spaces="true" style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; margin-bottom: 0pt; margin-top: 0pt;">0.5 = 9464 lb grain/(9464 lb grain + lb stover) gives 9464 lb stover/acre</span></p><p style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; color: #0e101a; margin-bottom: 0pt; margin-top: 0pt;"><span data-preserver-spaces="true" style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; margin-bottom: 0pt; margin-top: 0pt;"><br /></span></p><p style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; color: #0e101a; margin-bottom: 0pt; margin-top: 0pt;"><span data-preserver-spaces="true" style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; margin-bottom: 0pt; margin-top: 0pt;">Finally, the root-to-shoot ratio can be used to calculate how much root biomass is generated.</span></p><p style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; color: #0e101a; margin-bottom: 0pt; margin-top: 0pt;"><span data-preserver-spaces="true" style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; margin-bottom: 0pt; margin-top: 0pt;">0.21 = root/9464 lb stover gives root = 1987 lb root/acre</span></p><p style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; color: #0e101a; margin-bottom: 0pt; margin-top: 0pt;"><span data-preserver-spaces="true" style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; margin-bottom: 0pt; margin-top: 0pt;"><br /></span></p><p style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; color: #0e101a; margin-bottom: 0pt; margin-top: 0pt;"><span data-preserver-spaces="true" style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; margin-bottom: 0pt; margin-top: 0pt;"><i>The Livestock Connection: Stover as Bedding Material</i></span></p><p style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; color: #0e101a; margin-bottom: 0pt; margin-top: 0pt;"><span data-preserver-spaces="true" style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; margin-bottom: 0pt; margin-top: 0pt;"><i><br /></i></span></p><p style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; color: #0e101a; margin-bottom: 0pt; margin-top: 0pt;"><span data-preserver-spaces="true" style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; margin-bottom: 0pt; margin-top: 0pt;">The journey of corn stover continues beyond the fields. Harvested stover finds its way to livestock operations, where it takes on a new role as bedding material. Livestock farmers recognize the value of corn stover for providing comfortable and absorbent bedding for their animals.</span></p><p style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; color: #0e101a; margin-bottom: 0pt; margin-top: 0pt;"><span data-preserver-spaces="true" style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; margin-bottom: 0pt; margin-top: 0pt;"><br /></span></p><p style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; color: #0e101a; margin-bottom: 0pt; margin-top: 0pt;"><span data-preserver-spaces="true" style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; margin-bottom: 0pt; margin-top: 0pt;">A starting estimate for beef cattle bedding use in a bed pack barn is around 5 pounds per head per day or about 1800 lb per year. We want to harvest about 1 ton per head.</span></p><p style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; color: #0e101a; margin-bottom: 0pt; margin-top: 0pt;"><span data-preserver-spaces="true" style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; margin-bottom: 0pt; margin-top: 0pt;"><br /></span></p><p style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; color: #0e101a; margin-bottom: 0pt; margin-top: 0pt;"><em style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; margin-bottom: 0pt; margin-top: 0pt;">The Return: Manure Application</em></p><p style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; color: #0e101a; margin-bottom: 0pt; margin-top: 0pt;"><em style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; margin-bottom: 0pt; margin-top: 0pt;"><br /></em></p><p style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; color: #0e101a; margin-bottom: 0pt; margin-top: 0pt;"><span data-preserver-spaces="true" style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; margin-bottom: 0pt; margin-top: 0pt;">As livestock bedding breaks down, it decomposes, releasing nutrients and organic matter into the manure. When this nutrient-rich manure is reapplied to the fields, it returns a significant amount of organic carbon. This return of organic matter is vital to soil health and carbon sequestration.</span></p><p style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; color: #0e101a; margin-bottom: 0pt; margin-top: 0pt;"><span data-preserver-spaces="true" style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; margin-bottom: 0pt; margin-top: 0pt;">A typical bed pack manure is around 20 lb N per ton (Assume 50% 1st year available, 5% volatilization losses), and each space generates 6 tons of manure annually. To make this easier, I will assume a manure application rate of 6 tons/acre at 70% moisture or 1.8 tons dry matter.</span></p><p style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; color: #0e101a; margin-bottom: 0pt; margin-top: 0pt;"><span data-preserver-spaces="true" style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; margin-bottom: 0pt; margin-top: 0pt;"><br /></span></p><p style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; color: #0e101a; margin-bottom: 0pt; margin-top: 0pt;"><span data-preserver-spaces="true" style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; margin-bottom: 0pt; margin-top: 0pt;">The carbon flow in this system resembles a cyclic rhythm, echoing the sustainable principles of nutrient recycling. The manure application not only replenishes the carbon lost during stover harvesting but also contributes to the overall organic matter content in the soil.</span></p><p style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; color: #0e101a; margin-bottom: 0pt; margin-top: 0pt;"><span data-preserver-spaces="true" style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; margin-bottom: 0pt; margin-top: 0pt;"><br /></span></p><p style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; color: #0e101a; margin-bottom: 0pt; margin-top: 0pt;"><em style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; margin-bottom: 0pt; margin-top: 0pt;">The Balancing Act: Where does this leave us?</em></p><p style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; color: #0e101a; margin-bottom: 0pt; margin-top: 0pt;"><em style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; margin-bottom: 0pt; margin-top: 0pt;"><br /></em></p><p style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; color: #0e101a; margin-bottom: 0pt; margin-top: 0pt;"><span data-preserver-spaces="true" style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; margin-bottom: 0pt; margin-top: 0pt;">So now, the fun part is making assumptions to track organic matter. There are many complicated models to help track soil organic carbon, but in the interest of time and ease, I will make assumptions to simplify what is happening. I am assuming 10% of above-ground biomass is transformed into soil organic matter and that, similarly, 10% of applied manure becomes soil organic matter. For roots, I am going to be more aggressive and say 30% of that material becomes soil organic matter. Some fraction of the soil organic matter also needs to mineralize per year, and unfortunately, I do not have a good rule of thumb on what this is – so I estimated it for a continuous corn system by assuming equilibrium at a known soil organic matter content, in this case, 5% soil organic matter which suggested annual organic matter mineralization of 1.5%. This organic matter mineralization was then used in the stover harvest-manure application case to estimate the soil organic matter content under this operation. Carbon flows estimated are shown in Table 1.</span></p><p style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; color: #0e101a; margin-bottom: 0pt; margin-top: 0pt;"><span data-preserver-spaces="true" style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; margin-bottom: 0pt; margin-top: 0pt;"><br /></span></p><p style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; color: #0e101a; margin-bottom: 0pt; margin-top: 0pt; text-align: center;"><span data-preserver-spaces="true" style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; margin-bottom: 0pt; margin-top: 0pt;">Table 1. Carbon flows in a continuous corn system and in a continuous corn system with stover harvest and manure application. </span></p><div align="center">
<table border="0" cellpadding="0" cellspacing="0" class="MsoNormalTable" style="border-collapse: collapse; mso-padding-alt: 0in 5.4pt 0in 5.4pt; mso-yfti-tbllook: 1184; width: 588px;">
<tbody><tr style="height: 15.75pt; mso-yfti-firstrow: yes; mso-yfti-irow: 0;">
<td nowrap="" style="border-bottom: double windowtext 2.25pt; border-left: none; border-right: none; border-top: solid windowtext 1.0pt; height: 15.75pt; mso-border-bottom-alt: double windowtext 2.25pt; mso-border-top-alt: solid windowtext .5pt; padding: 0in 5.4pt 0in 5.4pt; width: 2.25in;" valign="bottom" width="216">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;"><b> <o:p></o:p></b></p>
</td>
<td nowrap="" style="border-bottom: double windowtext 2.25pt; border-left: none; border-right: none; border-top: solid windowtext 1.0pt; height: 15.75pt; mso-border-bottom-alt: double windowtext 2.25pt; mso-border-top-alt: solid windowtext .5pt; padding: 0in 5.4pt 0in 5.4pt; width: 1.0in;" valign="bottom" width="96">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;"><b>Continuous Corn<o:p></o:p></b></p>
</td>
<td nowrap="" style="border-bottom: double windowtext 2.25pt; border-left: none; border-right: none; border-top: solid windowtext 1.0pt; height: 15.75pt; mso-border-bottom-alt: double windowtext 2.25pt; mso-border-top-alt: solid windowtext .5pt; padding: 0in 5.4pt 0in 5.4pt; width: 207.0pt;" valign="bottom" width="276">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;"><b>Continuous Corn</b></p><p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;"><b>Stover Harvest
& Manure Application<o:p></o:p></b></p>
</td>
</tr>
<tr style="height: 15.75pt; mso-yfti-irow: 1;">
<td nowrap="" style="height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 2.25in;" valign="bottom" width="216">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">Grain Yield<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 1.0in;" valign="bottom" width="96">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">200<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 207.0pt;" valign="bottom" width="276">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">200<o:p></o:p></p>
</td>
</tr>
<tr style="height: 15.0pt; mso-yfti-irow: 2;">
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 2.25in;" valign="bottom" width="216">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">Corn Mass<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 1.0in;" valign="bottom" width="96">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">9,464<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 207.0pt;" valign="bottom" width="276">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">9,464<o:p></o:p></p>
</td>
</tr>
<tr style="height: 15.0pt; mso-yfti-irow: 3;">
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 2.25in;" valign="bottom" width="216">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">Harvest Index<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 1.0in;" valign="bottom" width="96">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">0.5<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 207.0pt;" valign="bottom" width="276">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">0.5<o:p></o:p></p>
</td>
</tr>
<tr style="height: 15.0pt; mso-yfti-irow: 4;">
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 2.25in;" valign="bottom" width="216">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">Corn Stover Dry Mass<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 1.0in;" valign="bottom" width="96">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">9,464<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 207.0pt;" valign="bottom" width="276">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">9,464<o:p></o:p></p>
</td>
</tr>
<tr style="height: 15.0pt; mso-yfti-irow: 5;">
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 2.25in;" valign="bottom" width="216">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">Root to Shoot<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 1.0in;" valign="bottom" width="96">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">0.21<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 207.0pt;" valign="bottom" width="276">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">0.21<o:p></o:p></p>
</td>
</tr>
<tr style="height: 15.0pt; mso-yfti-irow: 6;">
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 2.25in;" valign="bottom" width="216">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">Root Mass<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 1.0in;" valign="bottom" width="96">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">1,987<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 207.0pt;" valign="bottom" width="276">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">1,987<o:p></o:p></p>
</td>
</tr>
<tr style="height: 15.0pt; mso-yfti-irow: 7;">
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 2.25in;" valign="bottom" width="216">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">Manure Applied<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 1.0in;" valign="bottom" width="96">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">0<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 207.0pt;" valign="bottom" width="276">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">3,600<o:p></o:p></p>
</td>
</tr>
<tr style="height: 15.0pt; mso-yfti-irow: 8;">
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 2.25in;" valign="bottom" width="216">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">Stover Harvest<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 1.0in;" valign="bottom" width="96">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">0<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 207.0pt;" valign="bottom" width="276">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">2,000<o:p></o:p></p>
</td>
</tr>
<tr style="height: 15.0pt; mso-yfti-irow: 9;">
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 2.25in;" valign="bottom" width="216">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">Respired Corn Stover<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 1.0in;" valign="bottom" width="96">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">8,518<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 207.0pt;" valign="bottom" width="276">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">6,718<o:p></o:p></p>
</td>
</tr>
<tr style="height: 15.0pt; mso-yfti-irow: 10;">
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 2.25in;" valign="bottom" width="216">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">Respired Corn Root<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 1.0in;" valign="bottom" width="96">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">1,391<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 207.0pt;" valign="bottom" width="276">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">1,391<o:p></o:p></p>
</td>
</tr>
<tr style="height: 15.0pt; mso-yfti-irow: 11;">
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 2.25in;" valign="bottom" width="216">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">Manure Respired<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 1.0in;" valign="bottom" width="96">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">0<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 207.0pt;" valign="bottom" width="276">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">3,240<o:p></o:p></p>
</td>
</tr>
<tr style="height: 15.0pt; mso-yfti-irow: 12;">
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 2.25in;" valign="bottom" width="216">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">Corn Stover to SOM<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 1.0in;" valign="bottom" width="96">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">946<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 207.0pt;" valign="bottom" width="276">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">746<o:p></o:p></p>
</td>
</tr>
<tr style="height: 15.0pt; mso-yfti-irow: 13;">
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 2.25in;" valign="bottom" width="216">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">Corn Root to SOM<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 1.0in;" valign="bottom" width="96">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">596<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 207.0pt;" valign="bottom" width="276">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">596<o:p></o:p></p>
</td>
</tr>
<tr style="height: 15.0pt; mso-yfti-irow: 14;">
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 2.25in;" valign="bottom" width="216">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">Manure to SOM<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 1.0in;" valign="bottom" width="96">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">0<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 207.0pt;" valign="bottom" width="276">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">360<o:p></o:p></p>
</td>
</tr>
<tr style="height: 15.0pt; mso-yfti-irow: 15;">
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 2.25in;" valign="bottom" width="216">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">SOM Added<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 1.0in;" valign="bottom" width="96">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">1,543<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 207.0pt;" valign="bottom" width="276">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">1,703<o:p></o:p></p>
</td>
</tr>
<tr style="height: 15.0pt; mso-yfti-irow: 16;">
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 2.25in;" valign="bottom" width="216"></td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 1.0in;" valign="bottom" width="96"></td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 207.0pt;" valign="bottom" width="276">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">0<o:p></o:p></p>
</td>
</tr>
<tr style="height: 15.0pt; mso-yfti-irow: 17;">
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 2.25in;" valign="bottom" width="216">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">Original Soil Organic Matter<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 1.0in;" valign="bottom" width="96">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">5.0<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 207.0pt;" valign="bottom" width="276">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">5.5<o:p></o:p></p>
</td>
</tr>
<tr style="height: 15.0pt; mso-yfti-irow: 18;">
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 2.25in;" valign="bottom" width="216">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">Organic Matter in Acre<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 1.0in;" valign="bottom" width="96">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">100,000<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 207.0pt;" valign="bottom" width="276">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">110,400<o:p></o:p></p>
</td>
</tr>
<tr style="height: 15.0pt; mso-yfti-irow: 19;">
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 2.25in;" valign="bottom" width="216">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">Percent OM Mineralized per Year<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 1.0in;" valign="bottom" width="96">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">1.5<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 207.0pt;" valign="bottom" width="276">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">1.5<o:p></o:p></p>
</td>
</tr>
<tr style="height: 15.0pt; mso-yfti-irow: 20; mso-yfti-lastrow: yes;">
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 15.0pt; mso-border-bottom-alt: solid windowtext .5pt; padding: 0in 5.4pt 0in 5.4pt; width: 2.25in;" valign="bottom" width="216">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">Organic Matter Mineralized<o:p></o:p></p>
</td>
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 15.0pt; mso-border-bottom-alt: solid windowtext .5pt; padding: 0in 5.4pt 0in 5.4pt; width: 1.0in;" valign="bottom" width="96">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">1543<o:p></o:p></p>
</td>
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 15.0pt; mso-border-bottom-alt: solid windowtext .5pt; padding: 0in 5.4pt 0in 5.4pt; width: 207.0pt;" valign="bottom" width="276">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">1703<o:p></o:p></p>
</td>
</tr>
</tbody></table>
</div><p class="MsoNormal" style="text-align: center;"></p><p class="MsoNormal">A few thoughts, this exercise is meant to be illustrative,
and not determining of an exact field as the overall process was vastly simplified.
However, with that said, our results indicated that higher organic matter would
be expected in a field where stover is harvested for bedding and then that
material applied as a manure. This should be expected, because on net, the more
organic matter is added because of the cattle excrement and is removed from the
field.<o:p></o:p></p>
<p class="MsoNormal">Of course, there are many complicating factors. Examples
include, how does the use of manure impact tillage choices at the farm? If the
farm was no-till and then choose to use manure, perhaps a tillage pass is
added. This tillage pass would almost certainly increase the rate of soil
organic matter mineralization. Does more organic matter in the soil increase the
percent of organic matter mineralized per year? I think it almost certainly has
to, but I didn’t model it as such here because I don’t have data to suggest a
new rate of mineralization. With that said, even with these caveats I think the
balance and process are illustrative as they help us understand some of the
approaches we can use to get a feel for how different practices might impact
our soil.<o:p></o:p></p>
<p class="MsoNormal" style="text-align: left;"><i>Conclusion: A Symphony of Sustainability</i><o:p></o:p></p>
<p class="MsoNormal" style="text-align: left;">In the realm of continuous corn systems where corn stover is
harvested for livestock bedding and later reapplied with manure, the carbon
flows represent a dynamic interplay between extraction and replenishment.
Striking a balance between the needs of crop production and livestock
management is essential for ensuring the long-term sustainability of
agricultural ecosystems. In many respects what I showed here is simple, I
matched the harvested area with an area that is going to receive manure. There
could be places where this isn’t the case. By understanding and respecting the
nuances of carbon flows, we can foster agricultural systems that not only meet
the demands of the present but also preserve the vitality of the land for
generations to come.<o:p></o:p></p><br /><p></p>Daniel Andersenhttp://www.blogger.com/profile/17296164974381593950noreply@blogger.com0tag:blogger.com,1999:blog-8695306981003495902.post-46544730739182812642023-09-27T17:09:00.001-05:002023-09-27T17:09:33.240-05:00Optimizing Crop Success: The Crucial Role of Manure Application Timing in Iowa<p> As we embark on another agricultural season here in Iowa,
it's time to delve into a critical aspect of farming that often goes unnoticed
but plays a pivotal role in the success of our crops: manure application
timing. While it might not be the most glamorous topic, understanding when and
how we apply manure can significantly impact our yields and the environment.</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal">Manure has long been regarded as a valuable resource in Iowa
agriculture. It provides essential nutrients like nitrogen, phosphorus, and
potassium to our crops, reducing the need for synthetic fertilizers. However, manure
application timing is key to maximizing its benefits while minimizing potential
drawbacks.<o:p></o:p></p>
<p class="MsoNormal"><i style="mso-bidi-font-style: normal;">The Early Bird Gets
the Worm: Spring Application<o:p></o:p></i></p>
<p class="MsoNormal">As the frost thaws and fields become workable in the spring,
many Iowa farmers opt to apply manure. This timing aligns with planting, making
it convenient to incorporate manure into the soil before sowing or
transplanting seedlings. Spring application allows crops to access nutrients as
they need them throughout the growing season, promoting healthy development.<o:p></o:p></p>
<p class="MsoNormal">However, spring application comes with its challenges.
Manure can be challenging to work into the soil when wet, and timing must align
with field conditions, which can be unpredictable in Iowa's temperate climate.
There's also the risk of nutrient runoff during heavy spring rains, potentially
impacting water quality in our rivers and streams.<o:p></o:p></p>
<p class="MsoNormal"><i style="mso-bidi-font-style: normal;">Fall Application: A
Sensible Alternative<o:p></o:p></i></p>
<p class="MsoNormal">Fall application allows farmers to take advantage of drier
field conditions and can help reduce the risk of nutrient loss to runoff at the
time of application. The nutrients have more time to break down and become
available to crops over the winter months. However, there's a trade-off; some nitrogen
may be lost to the environment, and more extended periods between application
and crop growth allow the conversion of manure nitrogen to nitrate, a form that
is highly susceptible to loss.<o:p></o:p></p>
<p class="MsoNormal"><i style="mso-bidi-font-style: normal;">The Balancing Act<o:p></o:p></i></p>
<p class="MsoNormal">The choice between spring and fall application isn't
one-size-fits-all. It depends on various factors, including the specific crop,
soil type, and weather patterns. As we move forward in Iowa agriculture, it's
crucial to continue implementing sustainable farming practices. Manure
application timing is just one piece of the puzzle. By striking the right
balance, Iowa farmers can nourish their crops efficiently while safeguarding
our precious natural resources.<o:p></o:p></p>
<p class="MsoNormal">Manure application timing is not a minor detail but fundamental
to successful and responsible farming in Iowa. Careful consideration of when
and how we apply manure is essential to maximizing manure as a fertilizer
resource and protecting the environment. Farmers are encouraged to wait to
apply manure until soil temperatures are consistently trending cooler (towards
50<span style="font-family: "Arial",sans-serif;">º</span>F) to ensure the
nitrogen will remain in the soil until crops are planted next spring.<o:p></o:p></p>Daniel Andersenhttp://www.blogger.com/profile/17296164974381593950noreply@blogger.com0tag:blogger.com,1999:blog-8695306981003495902.post-44103825385517720222023-08-21T16:31:00.001-05:002023-08-22T16:00:30.937-05:00Can Iowa Pork Offset Its Way to Carbon Neutral?<p> Written by Jacob Willsea</p><p><br /></p><p></p><p class="MsoNormal" style="text-indent: .5in;">Iowa is home to the largest swine
industry in the USA, housing 23 million pigs at any time. Between feeding,
processing, and manure handling/storage, the Iowa swine industry emits 0.5
metric tons (MT) of CO<sub>2e</sub> per pig space annually, totaling 11.5
million MT CO<sub>2e</sub>/year. Reduction of the carbon footprint for the pork
industry has been a topic of interest for years, resulting in improved energy
efficiency in animal housing and meat processing and greenhouse gas (GHG)
reductions in manure management. Some farms are implementing onsite renewable
energy systems to reduce their carbon footprint, including installing wind
turbines, solar panels, and anaerobic digesters. This begs the question: Can installing
renewable energy on farms make Iowa pork production carbon-neutral?<o:p></o:p></p>
<p class="MsoNormal" style="text-indent: .5in;">Let's start by looking at the
current Iowa electricity sector:<o:p></o:p></p><p class="MsoNormal" style="text-indent: .5in;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi7amUYhqQcsrBQQkwESR8PbjmsmIqAdQkkYh1tw27QVzT9EG93nuAyhn8SEWKqCnHjFr4TTj9fDCIv7sdWxPzBCr6KpvhF4jJd8eOvpBTfDbndTCNxdcyz9eV8NCtjbIXbsUI4D8qh-8IL4Gp2oFjfBRS01G_Q2j06KIcBocnuEfQKsLt3G1hBkV1Mur8/s1408/Iowa%20electricity%20production%20source.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em; text-align: center; text-indent: 0px;"><img border="0" data-original-height="947" data-original-width="1408" height="215" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi7amUYhqQcsrBQQkwESR8PbjmsmIqAdQkkYh1tw27QVzT9EG93nuAyhn8SEWKqCnHjFr4TTj9fDCIv7sdWxPzBCr6KpvhF4jJd8eOvpBTfDbndTCNxdcyz9eV8NCtjbIXbsUI4D8qh-8IL4Gp2oFjfBRS01G_Q2j06KIcBocnuEfQKsLt3G1hBkV1Mur8/s320/Iowa%20electricity%20production%20source.png" width="320" /></a></p><p class="MsoNormal" style="text-indent: .5in;">Figure 1. Iowa electricity generation source.</p>
<p class="MsoNormal" style="text-indent: .5in;">Despite renewable energy sources
supplying 57% of Iowa's energy, the energy industry still emits 0.38 MT CO<sub>2e</sub>
per megawatt-hour (MWh) of electricity produced. Therefore, to offset the 11.5
million MT CO<sub>2e</sub> produced by the pork industry, an additional 30
million MWh of renewable energy would need to be supplied to the grid. One
option for providing this energy to the grid could be the installation of wind
turbines on farms. <o:p></o:p></p>
<p class="MsoNormal" style="text-indent: .5in;">Thirty-seven million MWh of Iowa's
energy is currently supplied by the 12,500 MW of wind turbines installed across
the state. To make up the required 30 million MWh to offset the swine industry,
another 10,100 MW of wind turbines would have to be installed. About 10 MW of
wind turbines can be placed on one section of land (1 mi<sup>2</sup>), so installing
10,100 MW would occupy about 650,000 acres. Although wind turbines can be
farmed around, they still eliminate about 0.75 ac of farmable land/MW installed
due to required access roads, concrete footings, and power substations. This
loss equals $0.43/pig space from reduced corn sales (200 bu/ac and $6.50/bu). The
wind turbines would produce about 1,310 kWh/pig space-year. On average, a swine
farm uses only 26 kWh/pig space-year, so the farmer can return 1,284 kWh/pig
space to the grid. The energy company's electricity buyback rate of $0.06/kWh
would yield $77/pig space per year for the farmer. Wind turbines cost about
$1,000,000/MW installed, so installing 10,100 MW of wind turbines would cost
about $440/pig space. Assuming a project life of 10-years, a time value of
money of 8%, <span style="mso-spacerun: yes;"> </span>and that maintenance on the
windturbines is $24,000 per MWh per year, then after selling the electricity
back to the grid and accounting for crop loss the project would have a net present
cost of $0/pig space. <o:p></o:p></p>
<p class="MsoNormal" style="text-indent: .5in;">An alternative renewable
electricity source could be solar power. Solar panel efficiency is continuously
improving. Could we offset the swine GHG emissions with solar power?<o:p></o:p></p>
<p class="MsoNormal" style="text-indent: .5in;">Technological developments have
improved the efficiency of solar panels to about 20%. Full sunlight supplies
about 0.93 kWh/ft<sup>2</sup>, so with Iowa's 4 hours of full sun each day, a
solar panel could absorb 0.37 kWh/ft<sup>2</sup>/day and output 27.13 kWh/ft<sup>2</sup>/year.
To produce the required 30 million MWh of electricity, about 25,500 acres of
solar panels, or 48 ft<sup>2</sup>/pig space, would have to be installed across
Iowa.<o:p></o:p></p>
<p class="MsoNormal" style="text-indent: .5in;">Like wind turbines, solar panels
would make $77/pig space from selling electricity to the grid. Assuming the
solar panels are installed on farmable land, the farms would take a loss from
reduced crop production. If a farmer installs 48 ft<sup>2</sup> of solar panels
per pig space instead of planting corn, the farmer will lose about $1.44/pig
space/year from reduced productivity. The capital cost for the solar panel
installation is about $450,000/acre, which equates to $500/pig space. After
selling electricity back to the grid, the total cost for this project would be
$328/pig space over a ten year project life.<o:p></o:p></p>
<p class="MsoNormal" style="text-indent: .5in;">Recall that 30 million MWh of
fossil fuel-based electricity must be replaced with renewable electricity to offset
the swine industry fully. Let's revisit the overview of the Iowa electricity
sector, this time with the electricity output in MWh:</p><p class="MsoNormal" style="text-indent: .5in;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjN8ab1W785oPGCWHuN_ZV8jjNyx1f9KD17cKDCQiRYaaiYD1TIS3hfvz39f04VcwCFe6RANre0RHNGs0jFyNifoBDoYJrmcqQXPox6fVCeweP2pKhBQLtDDQB0I0cWi57cJNV8o5FlIBZ8kx9QMwTFH_KeDphP0V1QgsJ-v5y7SShYc_lsvV91lVvEXCQ/s985/Iowa%20elecricity%202.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em; text-align: center;"><img border="0" data-original-height="556" data-original-width="985" height="181" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjN8ab1W785oPGCWHuN_ZV8jjNyx1f9KD17cKDCQiRYaaiYD1TIS3hfvz39f04VcwCFe6RANre0RHNGs0jFyNifoBDoYJrmcqQXPox6fVCeweP2pKhBQLtDDQB0I0cWi57cJNV8o5FlIBZ8kx9QMwTFH_KeDphP0V1QgsJ-v5y7SShYc_lsvV91lVvEXCQ/s320/Iowa%20elecricity%202.png" width="320" /></a></p><p></p><p>Figure 2. MWhs of electrical generation form renewable and non-renewable sources annually in Iowa.<br />
</p><p class="MsoNormal" style="text-indent: .5in;">Fossil fuels only produce 28.7
million MWh/year of electricity in Iowa. Therefore, even if all non-renewable
fuel sources were replaced with renewable electricity today, 30 million MWh
cannot be offset. Furthermore, the value of 30 million MWh is estimated using
the electricity sector's carbon intensity (CI) score. The CI score measures GHG
emissions per unit of energy output. The CI score is the baseline for
estimating the amount of renewable electricity it would take to offset fossil
fuel emissions. With every improvement in the electricity sector, lower levels
of GHGs are emitted for every unit of electricity produced, meaning a lower CI
score. As the grid becomes greener, it will continually take more renewable
electricity to offset the same amount of CO<sub>2e</sub>. The graph below illustrates
how the solar panel area required to offset one MT CO<sub>2e</sub> changes as
the electrical grid shifts toward renewable energy.<o:p></o:p></p>
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiIDO4YPP3i2u-3Yn7C-16GGmqkuSKsb9jaRRNFVAg5MgzwRmKbJiMaQBB5iwic7jUrZemFG7H16-TxGCJTG0GbvXj0UOMOuxzh8Ytii4XLMIGi_4HMEraMHW4R40vIP5Censyi-szDm3caWXgnPjVtFO7b09VuYUzwv6BJCMRxN0PVs9JPnzemiTNuZCA/s1578/Iowa%20electricity%203.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em; text-align: center;"><img border="0" data-original-height="506" data-original-width="1578" height="174" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiIDO4YPP3i2u-3Yn7C-16GGmqkuSKsb9jaRRNFVAg5MgzwRmKbJiMaQBB5iwic7jUrZemFG7H16-TxGCJTG0GbvXj0UOMOuxzh8Ytii4XLMIGi_4HMEraMHW4R40vIP5Censyi-szDm3caWXgnPjVtFO7b09VuYUzwv6BJCMRxN0PVs9JPnzemiTNuZCA/w541-h174/Iowa%20electricity%203.png" width="541" /></a><p></p><p>Figure 3. Installation of solar panels required to achieve different levels of carbon reduction as a function of a cleaner electrical generation grid resulting from clean energy installation.<br />
</p><p class="MsoNormal"><span style="mso-tab-count: 1;"> </span>The
calculations so far have all assumed a constant electricity demand in the
coming years. Electricity demand will increase proportionally with the increase
in electric vehicles (EVs) on Iowa roads. Today, EVs comprise only 0.2% of Iowa's
2.5 million registered vehicles. Every EV requires 3.9 MWh/year, so if Iowa had
100% EVs on the roads, the electric grid would need to supply an additional 9.4
million MWh annually. Although this increase in electricity demand would make
the transition from fossil fuels for electricity production take longer, the
full transition to a renewable electric grid is inevitable. <o:p></o:p></p>
<p class="MsoNormal" style="text-indent: .5in;">Here is the key takeaway: while
adopting renewable electricity systems on farms will support our progression
toward a fully-renewable grid and energy independence, it can be a good way to
consider your swine farm "green" or "carbon neutral," that
title will only be temporary. A future increase in electricity demand will
allow farms to consider themselves carbon neutral for a longer period, but once
the grid <i style="mso-bidi-font-style: normal;">does</i> become fully renewable,
emitting no GHGs, your solar panels and wind turbines will no longer be
offsetting any emissions, and your swine farm will be a net emitter of GHGs again.
This highlights the unfortunate fact that farms will not be able to credit
their way to net zero emissions, underscoring the importance of other on-farm
strategies that must be implemented for emission reduction. <o:p></o:p></p>
<p class="MsoNormal" style="text-indent: .5in;">Manure management is one of the
direct methods to reduce your carbon emissions. Upgrades to your storage
systems, including covered lagoons and anaerobic digesters, can capture and
utilize the methane emissions from your storage. Manure application timing can
also make significant impacts on your carbon emissions. Spring and split
applications of manure throughout the growing season can limit the length and
amount of manure in storage, once again reducing the overall emissions from
your farm.</p><p></p><div class="separator" style="clear: both; text-align: center;"><br /></div><br /><div class="separator" style="clear: both; text-align: center;"><br /></div><br /><div class="separator" style="clear: both; text-align: center;"><br /></div><br /><br />Daniel Andersenhttp://www.blogger.com/profile/17296164974381593950noreply@blogger.com1tag:blogger.com,1999:blog-8695306981003495902.post-78964870952026913832023-07-24T08:34:00.000-05:002023-07-24T08:34:13.118-05:00Nitrogen Circularity in Swine Finishing<p> </p><p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><span style="color: #0e101a; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";">The circularity of
nitrogen in swine finishing production refers to the management and utilization
of nitrogen within the swine production system to minimize waste. Nitrogen is
an essential nutrient for pigs, but its improper management can lead to
environmental issues such as water pollution, ammonia loss, and greenhouse gas
emissions. The concept of circularity refers to the percent or fraction of
nitrogen that is kept within the cycle and can be used again.<o:p></o:p></span></p>
<p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><span style="color: #0e101a; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";">Nitrogen circularity in
swine finishing encompasses at least four areas.<o:p></o:p></span></p>
<p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><span style="color: #0e101a; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";"><o:p> </o:p></span></p>
<ol start="1" style="margin-top: 0in;" type="1">
<li class="MsoNormal" style="color: #0e101a; line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; mso-list: l0 level1 lfo1; tab-stops: list .5in;"><span style="mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";">Feed Management: Balancing the
feed composition with the pig's nutritional requirements minimizes
nitrogen in manure. Nitrogen is lost during manure storage and recycling
for crop production. As such, maximizing nitrogen retention in the pig is
critical for improved circularity. However, the choice of managing manure
as a waste or resource is often dictated by the ability of farmers to use
the manure more cost-effectively than commercial fertilizer could be
applied. If manure is treated as a waste, typically, circularity is
reduced. Finally, diet ingredient selection impacts system efficiency by
its relationship to crop production and crop selection and the nitrogen
use efficacy in the cropping system. <o:p></o:p></span></li>
<li class="MsoNormal" style="color: #0e101a; line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; mso-list: l0 level1 lfo1; tab-stops: list .5in;"><span style="mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";">Manure Management: Efficient
handling and treatment of swine manure can minimize nitrogen losses and
environmental impacts. During manure storage, nitrogen is volatilized to
the atmosphere and lost. Technologies such as anaerobic digestion, impermeable
covers, and acidification can help reduce this loss. Retaining nitrogen
for recycling for crop production is critical for circularity.<o:p></o:p></span></li>
<li class="MsoNormal" style="color: #0e101a; line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; mso-list: l0 level1 lfo1; tab-stops: list .5in;"><span style="mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";">Nutrient Management: Implementing
nutrient management plans on swine farms can guide the appropriate
application of manure to cropland, ensuring optimal nitrogen utilization.
By matching the nutrient content of manure with the crop's nutrient
requirements, over-application can be avoided, reducing the risk of
nitrogen loss and increasing circularity. Manure application method and
timing strongly impact the ability to recover applied nitrogen.<o:p></o:p></span></li>
<li class="MsoNormal" style="color: #0e101a; line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; mso-list: l0 level1 lfo1; tab-stops: list .5in;"><span style="mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";">Crop Rotation and Cover Crops:
Integrating crop rotation and cover crops into the farming system can
improve nitrogen cycling. Selection of rotations can reduce nitrogen need
for subsequent crops and increase yield relative to limited rotations.
Nitrogen-fixing cover crops, such as legumes, can capture atmospheric
nitrogen and make it available to subsequent crops. Cover crops have been
shown to reduce nitrogen leaching, potentially keeping more nitrogen in
the profile for use by subsequent crops.<o:p></o:p></span></li>
</ol>
<p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><span style="color: #0e101a; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";"><o:p> </o:p></span><span style="color: #0e101a;">Nitrogen circularity is
a complex issue that requires a holistic approach. Regulations, incentives, and
education can play a vital role in supporting and encouraging the adoption of sustainable
nitrogen management practices in the swine finishing industry, but a critical
first step is understanding how different systems compare and how other options
impact nitrogen circularity. Nitrogen circularity, and our understanding of it,
is an ever-evolving topic that we can continue to better understand to make
informed decisions that help keep our cropland in Iowa the most productive in
the world at providing the food, fuel, and fiber we need.</span></p>
<p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><span style="color: #0e101a; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";"><o:p> </o:p></span><span style="color: #0e101a;">To illustrate these
concepts, we will look at four systems focused on two different diets
(Corn-DDGS and Corn-Soybean Meal), two different manure systems (deep pit and
lagoon), and one manure application rate (yield goal rate with any purchased
nitrogen fertilizer applied at the ISU maximum return to nitrogen rate) and
cropping system focused on an optimized cropping system to supply soybean
needed for the diet; manure is then applied to equivalent acres of corn to the
amount of soybean that was raised with any manure nitrogen remaining above this
level applied to corn raised in a continuous corn rotation.</span></p>
<p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><span style="color: #0e101a; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";"><o:p> </o:p></span><span style="color: #0e101a;">Schematics are shown in
the four figures below. While the presentation is linear, showing a flow from
left to right, the final crops on the right only need processing to become the
feed ingredients on the left and begin the cycle again.</span></p><p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"></p><p class="MsoNormal"><span style="mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";"><o:p> </o:p></span></p>
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjoTmg0MluJeSav-xlg0FFrbUmJIMIWUHY_CaauPowumXnpK3-uKQjopD-L_-0l_ZGdNnBSTfQlp3qxAVoew5sIkZzfNr1Ay8tlamAxV05LcxNpmT9bISEkRhuRVqrIO8MLMiqIifSTNeGjcVnEI7LSlvCd53yksk_NbNMNX7wm-tEmB9W9vEjxnzI4qU4/s1424/Figure1.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="756" data-original-width="1424" height="343" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjoTmg0MluJeSav-xlg0FFrbUmJIMIWUHY_CaauPowumXnpK3-uKQjopD-L_-0l_ZGdNnBSTfQlp3qxAVoew5sIkZzfNr1Ay8tlamAxV05LcxNpmT9bISEkRhuRVqrIO8MLMiqIifSTNeGjcVnEI7LSlvCd53yksk_NbNMNX7wm-tEmB9W9vEjxnzI4qU4/w647-h343/Figure1.png" width="647" /></a></div><p class="MsoNormal">Figure 1.
Corn-soybean meal diet with a deep pit manure storage and manure applied using
Iowa yield goal and commercial fertilizer applied at MRTN.</p>
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgK8Szwk1UPtYzzKLeKrTk_W-Z8pa4NYYaQ9fL3NpE0rPzckjZ2Z1alWHptFRe2UIv9T_KliSOxyZH3fTVrR_pRjmn_mbrCKMdbmSRiQz6E-yMZffrsUKM6GK3ZtySxn3BroRAq0gThK_skBbZnFu8-O9Z1R333D8YJP19AkXvX4VhA-VegWwydNEsBUMg/s1431/Figure2.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="768" data-original-width="1431" height="341" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgK8Szwk1UPtYzzKLeKrTk_W-Z8pa4NYYaQ9fL3NpE0rPzckjZ2Z1alWHptFRe2UIv9T_KliSOxyZH3fTVrR_pRjmn_mbrCKMdbmSRiQz6E-yMZffrsUKM6GK3ZtySxn3BroRAq0gThK_skBbZnFu8-O9Z1R333D8YJP19AkXvX4VhA-VegWwydNEsBUMg/w634-h341/Figure2.png" width="634" /></a></div><div class="separator" style="clear: both; text-align: center;"><span style="text-align: left;">Figure 2. Corn-DDGS diet with a deep pit manure storage and manure applied using Iowa yield goal and commercial fertilizer applied at MRTN.</span></div><br /><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgc1Bc4evyr3RQ1TcG5Zn5WdSy39Fl0iKJ6S06xjE6hTkCT_DRHerQ5Q1HQ5Ceo5fm4UpF4-qjitOdfkiBxLMtAu7UR1JzI9j8Wrr4pzletd-bWf25eb0sBmR2vOeS_BbzSJFs4YlvxikCMIVXOdvklZZBhOuWcGJkxF1i-Qglmqj_La3szGV7fgPcWDao/s1423/Figure3.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="743" data-original-width="1423" height="329" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgc1Bc4evyr3RQ1TcG5Zn5WdSy39Fl0iKJ6S06xjE6hTkCT_DRHerQ5Q1HQ5Ceo5fm4UpF4-qjitOdfkiBxLMtAu7UR1JzI9j8Wrr4pzletd-bWf25eb0sBmR2vOeS_BbzSJFs4YlvxikCMIVXOdvklZZBhOuWcGJkxF1i-Qglmqj_La3szGV7fgPcWDao/w629-h329/Figure3.png" width="629" /></a></div><div class="separator" style="clear: both; text-align: center;"><span style="text-align: left;">Figure 3. Corn-soybean meal diet with a lagoon manure storage and manure applied using Iowa yield goal and commercial fertilizer applied at MRTN.</span></div><br /><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg89m6lHg37PE5o7VdmQgR9QxStXfdhZ0gLYX7va9gnnWOA17M3yRmORxnKxOKvnxL_oGequU9aJ-NDi5ZfX4s9Ndkg9QqQ_XteB9P3fea0ppwOgiXNEjpJ6I3GTyPFm8RSgaXsbEU_F4XiS9rynYBBoyxSW47o9DsUnoYjpEzBQSpaQ-6Q8McJIk1tE6Q/s1427/Figure4.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="761" data-original-width="1427" height="348" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg89m6lHg37PE5o7VdmQgR9QxStXfdhZ0gLYX7va9gnnWOA17M3yRmORxnKxOKvnxL_oGequU9aJ-NDi5ZfX4s9Ndkg9QqQ_XteB9P3fea0ppwOgiXNEjpJ6I3GTyPFm8RSgaXsbEU_F4XiS9rynYBBoyxSW47o9DsUnoYjpEzBQSpaQ-6Q8McJIk1tE6Q/w650-h348/Figure4.png" width="650" /></a></div><p class="MsoNormal">Figure 4.
Corn-DDGS diet with a lagoon manure storage and manure applied using Iowa yield
goal and commercial fertilizer applied at MRTN.</p>
<p class="MsoNormal"><span style="mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";">Each figure shows
a nitrogen flow through the swine finishing cycle, including an estimate for
nitrogen fixation by the soybean. There are many ways of interpreting the
cycle, but I like to start with efficiency as an engineer. Efficiency is
defined as wanted output/inputs. In this case, the output would be the nitrogen
in the pig. Nitrogen inputs include the amino acid and synthetic fertilizer
nitrogen purchased to support crop production. Soybean complicates this
slightly –the nitrogen they provide is an input, but some of the nitrogen comes
from biological fixation and the rest from the soil. As I can't find a
reference for how to include them, I will estimate biological fixation and use
that fraction as an input.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";">Another metric
that is receiving more discussion is circularity. One means of defining
circularity is the percent of required nitrogen inputs obtained by recycling.
This would be the amount of nitrogen land applied with manures compared to the
total nitrogen needed for fertilizer (both manure and synthetic fertilizer) and
the amino acids in the feed. This might be termed "self-reliance"
circularity as it is the fraction of circularity an integrated farm could
control.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";">An alternative
circularity metric is the "recycling rate." The recycling rate is the
percentage of recycled products available for recycling. In our examples, this
would be the land-applied manure compared to the as excreted manure plus the
nitrogen in the pig. At first glance, including the nitrogen in the pig sounds
funny as it is the product, and we want it to be consumed. However, nitrogen is
available for recycling at the slaughter and rendering plant and in the human
wastewater treatment system, and including this term recognizes that fact and
shows how urban locations and areas of consumption must find ways to recover
this nutrient to create circular systems.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";"><span style="mso-spacerun: yes;"> </span>Table 1. System comparisons on different
performance metrics including efficiency and two circularity metrics.<o:p></o:p></span></p>
<table border="0" cellpadding="0" cellspacing="0" class="MsoNormalTable" style="border-collapse: collapse; margin-left: 5.4pt; mso-padding-alt: 0in 5.4pt 0in 5.4pt; mso-yfti-tbllook: 1184; width: 567px;">
<tbody><tr style="height: 15.75pt; mso-yfti-firstrow: yes; mso-yfti-irow: 0;">
<td nowrap="" style="border-bottom: double windowtext 2.25pt; border-left: none; border-right: none; border-top: solid windowtext 1.0pt; height: 15.75pt; mso-border-bottom-alt: double windowtext 2.25pt; mso-border-top-alt: solid windowtext .5pt; padding: 0in 5.4pt 0in 5.4pt; width: 103.5pt;" valign="bottom" width="138">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;"><b><span style="color: black; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";">System<o:p></o:p></span></b></p>
</td>
<td nowrap="" style="border-bottom: double windowtext 2.25pt; border-left: none; border-right: none; border-top: solid windowtext 1.0pt; height: 15.75pt; mso-border-bottom-alt: double windowtext 2.25pt; mso-border-top-alt: solid windowtext .5pt; padding: 0in 5.4pt 0in 5.4pt; width: 94.5pt;" valign="bottom" width="126">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;"><b><span style="color: black; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";">System Efficiency<o:p></o:p></span></b></p>
</td>
<td nowrap="" style="border-bottom: double windowtext 2.25pt; border-left: none; border-right: none; border-top: solid windowtext 1.0pt; height: 15.75pt; mso-border-bottom-alt: double windowtext 2.25pt; mso-border-top-alt: solid windowtext .5pt; padding: 0in 5.4pt 0in 5.4pt; width: 1.5in;" valign="bottom" width="144">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;"><b><span style="color: black; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";">Self-Reliance Circularity<o:p></o:p></span></b></p>
</td>
<td nowrap="" style="border-bottom: double windowtext 2.25pt; border-left: none; border-right: none; border-top: solid windowtext 1.0pt; height: 15.75pt; mso-border-bottom-alt: double windowtext 2.25pt; mso-border-top-alt: solid windowtext .5pt; padding: 0in 5.4pt 0in 5.4pt; width: 119.0pt;" valign="bottom" width="159">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;"><b><span style="color: black; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";">Recycling Rate Circularity<o:p></o:p></span></b></p>
</td>
</tr>
<tr style="height: 15.75pt; mso-yfti-irow: 1;">
<td nowrap="" style="height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 103.5pt;" valign="bottom" width="138">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;"><span style="color: black; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";">Corn-Soy Deep Pit<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 94.5pt;" valign="bottom" width="126">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;"><span style="color: black; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";">67<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 1.5in;" valign="bottom" width="144">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;"><span style="color: black; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";">71<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 119.0pt;" valign="bottom" width="159">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;"><span style="color: black; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";">52<o:p></o:p></span></p>
</td>
</tr>
<tr style="height: 15.0pt; mso-yfti-irow: 2;">
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 103.5pt;" valign="bottom" width="138">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;"><span style="color: black; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";">Corn-Soy Lagoon<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 94.5pt;" valign="bottom" width="126">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;"><span style="color: black; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";">51<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 1.5in;" valign="bottom" width="144">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;"><span style="color: black; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";">46<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 119.0pt;" valign="bottom" width="159">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;"><span style="color: black; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";">32<o:p></o:p></span></p>
</td>
</tr>
<tr style="height: 15.0pt; mso-yfti-irow: 3;">
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 103.5pt;" valign="bottom" width="138">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;"><span style="color: black; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";">Corn-DDGS Deep Pit<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 94.5pt;" valign="bottom" width="126">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;"><span style="color: black; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";">43<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 1.5in;" valign="bottom" width="144">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;"><span style="color: black; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";">42<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 119.0pt;" valign="bottom" width="159">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;"><span style="color: black; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";">54<o:p></o:p></span></p>
</td>
</tr>
<tr style="height: 15.0pt; mso-yfti-irow: 4; mso-yfti-lastrow: yes;">
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 15.0pt; mso-border-bottom-alt: solid windowtext .5pt; padding: 0in 5.4pt 0in 5.4pt; width: 103.5pt;" valign="bottom" width="138">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;"><span style="color: black; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";">Corn-DDGS Lagoon<o:p></o:p></span></p>
</td>
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 15.0pt; mso-border-bottom-alt: solid windowtext .5pt; padding: 0in 5.4pt 0in 5.4pt; width: 94.5pt;" valign="bottom" width="126">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;"><span style="color: black; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";">35<o:p></o:p></span></p>
</td>
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 15.0pt; mso-border-bottom-alt: solid windowtext .5pt; padding: 0in 5.4pt 0in 5.4pt; width: 1.5in;" valign="bottom" width="144">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;"><span style="color: black; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";">27<o:p></o:p></span></p>
</td>
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 15.0pt; mso-border-bottom-alt: solid windowtext .5pt; padding: 0in 5.4pt 0in 5.4pt; width: 119.0pt;" valign="bottom" width="159">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;"><span style="color: black; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";">34<o:p></o:p></span></p>
</td>
</tr>
</tbody></table>
<p class="MsoNormal"><span style="mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";">The recycling rate
tells how well we return potential residues into places of value. Nutrients
lost to volatilization during manure collection and storage are challenges that
must be addressed. While deep pit storages are an improvement over lagoons,
innovation is needed to help improve recycling rates further. Nutrients
exported with the pig may or may not be recycled depending on what happens at
the slaughter facility, the rendering plant, and the human wastewater treatment
plant. Within this analysis, I excluded them as they are beyond my scope;
however, for a better idea of how the agricultural system is performing, this
needs to be included and must be addressed, as these nutrient exports are on
the same order of magnitude as nitrogen losses during lagoon storage.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";">Self-reliance
circularity indicates what percent of the nitrogen needs are supplied by items
an integrated crop-livestock farm (or system) could control. An alternative way
of viewing this number is 100 minus the self-reliance circularity is our
reliance on nitrogen sources outside the farm's control. An integrated cropping
and swine finishing farm with a deep pit manure storage is currently proving
around 71% of the nitrogen it needs to feed a pig and fertilize its crops. An
interesting take-home here is that using soybean to biologically fix some of
the nitrogen for the diet improves self-reliance circularity significantly as
it reduces nitrogen demand to the following crop and provides nitrogen to the
manure that didn't originate from synthetic fertilizer or recycling materials.
This metric could also be improved by reducing ammonia losses during manure
collection and storage, improving rate selection for manure as a fertilizer
(probably mostly through improved application timing), and innovating ways to recycle
nitrogen that ends up at the slaughter, rendering, and human wastewater
treatment facilities.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";">Finally, we have
the system efficiency metric. This metric again favored soybean-based diets,
though in this case, this was at least in part due to diet formulations that
facilitated greater nitrogen retention in the pig and less excretion and at
least in part from reduced nitrogen inputs needed to achieve corn production.
This metric could also be improved by reducing ammonia volatilization during
collection and storage, as demonstrated by the differences between the lagoon
and deep pit systems.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";">A few caveats –
this is by no means an end-all-be-all analysis. Many assumptions were made to
facilitate the analysis; for example, I compared nutrient removal with corn
grain to the nitrogen fertilizer application rate to facilitate calculations
rather than trying to estimate N losses with nitrate leaching, surface water
runoff, or denitrification losses. In doing so, I inherently assumed nitrogen
additions through deposition didn't matter and that the soil nitrogen level was
in equilibrium and unchanging. Similarly, I looked at nitrogen soybeans fixed
from the atmosphere and didn't show nitrogen losses during their production.
Water measurements in tiled fields show nitrogen leaching in these production
systems. Similarly, co-products are produced from both diets – either soybean
oil or ethanol. While neither contains nitrogen and thus doesn't impact my
analysis with these parameters, recognizing that the system is more complicated
and contributing other goods is important in using these metrics.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";">All this is a
fancy way of saying things we already know. We, agricultural and agricultural
researchers, need (1) to innovate new solutions that help reduce ammonia losses
during manure collection and storage, (2) improve nitrogen rate selection with
fertilizers but especially manures (again probably through innovations that
facilitate improvements in manure application timing), (3) be mindful of how
crop rotation effects alter nutrient needs and alternative in-field management
practices (like cover crops) could alter losses and our ability to recycle
nutrients, and (4) that on-farm management only goes so far and that recycling
of consumed nutrients from urban areas where livestock products are consumed
has almost as large of impact on nitrogen recycling metrics as the ammonia
volatilization losses.<o:p></o:p></span></p><span style="color: #0e101a;"></span><p></p>Daniel Andersenhttp://www.blogger.com/profile/17296164974381593950noreply@blogger.com0tag:blogger.com,1999:blog-8695306981003495902.post-61332147303525275092023-06-13T09:35:00.004-05:002023-06-13T09:35:29.834-05:00Pursuing Carbon Neutrality in Livestock Production<p> <span style="color: #0e101a; font-family: "Times New Roman", serif; font-size: 12pt;">For livestock
facilities improving nitrogen circularity, reducing nutrient loss to air and
surface waters, and better utilization of manure have been hallmarks of
pursuing sustainability. Limiting the release of greenhouse gases has now been
added to that list.</span></p>
<p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><span style="color: #0e101a; font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";"><o:p> </o:p></span><span style="color: #0e101a; font-family: "Times New Roman", serif; font-size: 12pt;">Achieving
carbon-neutral livestock production requires implementing strategies to reduce
greenhouse gas emissions and offset any remaining emissions. In carbon
footprinting, there are three emissions scopes. Scope 1 Emissions are
greenhouse gas (GHG) emissions from operations owned or controlled by the
livestock producer. For livestock facilities, Scope 1 emissions are enteric
fermentation methane emissions and methane and nitrous oxide emissions from
manure storage practices. This category would also include emissions from the
combustion of propane used to heat livestock buildings or fuel used to power
equipment and tractors that handle mortality compost.</span></p>
<p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><span style="color: #0e101a; font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";"><o:p> </o:p></span><span style="color: #0e101a; font-family: "Times New Roman", serif; font-size: 12pt;">Scope 2 emissions are
indirect emissions resulting from the generation of purchased or acquired
electricity, steam, heating, or cooling. Typically, livestock fans would be
carbon dioxide generated from producing electricity to run building fans and
power other electric motors used in the feed delivery system.</span></p>
<p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><span style="color: #0e101a; font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";"><o:p> </o:p></span><span style="color: #0e101a; font-family: "Times New Roman", serif; font-size: 12pt;">Scope 3 emissions are
indirect emissions in the value chain, including upstream and downstream
emissions. These, for example, would include greenhouse gas emissions resulting
in feed production, including raising corn and soybean, grinding and delivering
it to the production facility, and emissions associated with moving livestock
or livestock products (milk, eggs) to the processing facility. It could also
include carbon costs associated with converting the animal (or animal product)
into a salable product at the grocery store.</span></p>
<p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><span style="color: #0e101a; font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";"><o:p> </o:p></span><span style="color: #0e101a; font-family: "Times New Roman", serif; font-size: 12pt;">While I attempt to
break these into neat categories by scope, it can be challenging as integrated
livestock facilities that produce feed on-farm for their livestock could be
considered Scope 1 emissions.</span></p>
<p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><span style="color: #0e101a; font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";"><o:p> </o:p></span><i><span style="color: #0e101a; font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";">Scope 1</span></i></p>
<ol start="1" style="margin-top: 0in;" type="1">
<li class="MsoNormal" style="color: #0e101a; line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; mso-list: l0 level1 lfo1; tab-stops: list .5in;"><span style="font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";">Manure Management: Implement efficient management
practices to minimize methane and nitrous oxide emissions. Anaerobic
digestion systems, which convert manure into biogas for energy production,
are a primary example. Other options include aeration, acidification,
frequent manure removal and application, and diet modification. Techniques
primarily focus on reducing methane emissions.<o:p></o:p></span></li>
<li class="MsoNormal" style="color: #0e101a; line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; mso-list: l0 level1 lfo1; tab-stops: list .5in;"><span style="font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";">Enteric Fermentation: Methane is produced during
digestion and fermentation in an animal's digestive tract. Developing
feeding strategies that reduce enteric fermentation is an active line of
research for dairy cattle, with products such as Monensin and seaweed
being suggested.<o:p></o:p></span></li>
<li class="MsoNormal" style="color: #0e101a; line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; mso-list: l0 level1 lfo1; tab-stops: list .5in;"><span style="font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";">Feed Efficiency: Enhance feed efficiency by utilizing
improved nutrition strategies, including formulating balanced diets and
adding feed additives. Improved feed efficiency reduces the amount of feed
required to produce a unit of meat, thereby lowering emissions associated
with feed production. Improved feed efficiency due to improved grinding
and, as a result, digestibility has been a key improvement in
environmental performance.<o:p></o:p></span></li>
<li class="MsoNormal" style="color: #0e101a; line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; mso-list: l0 level1 lfo1; tab-stops: list .5in;"><span style="font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";">Genetic Selection: Select swine breeds or genetic lines
with higher feed efficiency and lower emissions. Genetic improvements can
help reduce swine production's environmental impact over time and have
been key in our environmental efficiency gains. .<o:p></o:p></span></li>
</ol>
<p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><i><span style="color: #0e101a; font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";"><o:p> </o:p></span></i><i><span style="color: #0e101a; font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";">Scope 2</span></i></p>
<ol start="1" style="margin-top: 0in;" type="1">
<li class="MsoNormal" style="color: #0e101a; line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; mso-list: l2 level1 lfo2; tab-stops: list .5in;"><span style="font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";">Energy Efficiency: Improve energy efficiency in swine
production facilities by using energy-efficient equipment and optimizing
heating, ventilation, and lighting systems. Optimizing use reduces energy
consumption and associated emissions. Examples include switching lighting
to LED (an increasingly popular approach in poultry housing). Fan staging
to increase fan efficiency, installation of VFDs on fans to improve
performance, and closely monitoring minimum ventilation requirements to
reduce propane demand for maintaining barn temperature.<o:p></o:p></span></li>
<li class="MsoNormal" style="color: #0e101a; line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; mso-list: l2 level1 lfo2; tab-stops: list .5in;"><span style="font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";">Renewable Energy: Incorporate renewable energy sources
such as solar panels, wind turbines, or biogas systems to generate clean
energy for powering swine production facilities. Renewable energy can
significantly reduce carbon emissions. Many swine farms have started
adding solar panels to help generate clean energy, but so do changes in
energy supply technologies throughout the state.</span></li></ol>
<p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><i><span style="color: #0e101a; font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";">Scope 3</span></i><span style="color: #0e101a; font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";"><o:p></o:p></span></p>
<ol start="1" style="margin-top: 0in;" type="1">
<li class="MsoNormal" style="color: #0e101a; line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; mso-list: l1 level1 lfo3; tab-stops: list .5in;"><span style="font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";">Nutrient Management: Optimize nutrient management
practices to minimize the release of nitrous oxide, a potent greenhouse
gas. Nutrient management involves carefully managing the method and timing
of manure or synthetic fertilizers application to crops. Considering
nutrient content, timing, and soil conditions. Optimizing rate, timing,
method, and soil conditions is a huge topic and will continue to be
studied.<o:p></o:p></span></li>
<li class="MsoNormal" style="color: #0e101a; line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; mso-list: l1 level1 lfo3; tab-stops: list .5in;"><span style="font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";">Select feed ingredients from agricultural production
practices that result in lower carbon footprints of the supplied
materials. Life cycle analysis is helping differentiate how substituting
DDGS may impact feed carbon relative to soybean meal. Similarly, future
work will need to identify how recycling manure, use of cover crops, and
reduced tillage affect yield and greenhouse gas emissions, and the
digestibility and livestock performance interact to help inform ingredient
selection and inclusion rates. These factors will need to be balanced with
price and availability.</span></li></ol>
<p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><i><span style="color: #0e101a; font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";">Carbon Offsetting</span></i><span style="color: #0e101a; font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";"><o:p></o:p></span></p>
<p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><span style="color: #0e101a; font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";">Compensate for any
remaining emissions by investing in carbon offset projects. This can involve
supporting activities such as reforestation or using trees and grassland around
building sites to increase carbon storage, renewable energy projects that
reduce emissions beyond the farm, and implementing or participating in carbon
capture and storage projects.</span></p>
<p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><span style="color: #0e101a; font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";">Below, estimates of
different emissions for a deep pit swine finishing facility (wean to finish).
These estimates are meant to be illustrative, may not include all emissions,
and won't represent all farms.<o:p></o:p></span></p>
<p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><span style="color: #0e101a; font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";"><o:p> </o:p></span></p>
<ol start="1" style="margin-top: 0in;" type="1">
<li class="MsoNormal" style="color: #0e101a; line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; mso-list: l3 level1 lfo4; tab-stops: list .5in;"><span style="font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";">Manure Management: A deep pit swine storage would emit
approximately 192 kg CO<sub>2,e</sub>/head-year.<o:p></o:p></span></li>
<li class="MsoNormal" style="color: #0e101a; line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; mso-list: l3 level1 lfo4; tab-stops: list .5in;"><span style="font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";">Enteric Fermentation: IPCC Tier 1 approach estimates
1.5 kg CH<sub>4</sub>/hd-year, or 42 kg CO<sub>2,e</sub>/head-year.<o:p></o:p></span></li>
<li class="MsoNormal" style="color: #0e101a; line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; mso-list: l3 level1 lfo4; tab-stops: list .5in;"><span style="font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";">Barn Heat: Harmon et al. (Sizing minimum ventilation to
save heating energy in swine housing) estimated usage of 2 gallons per pig
space per year, or 11.4 kg CO<sub>2,e</sub>/head-year.<o:p></o:p></span></li>
<li class="MsoNormal" style="color: #0e101a; line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; mso-list: l3 level1 lfo4; tab-stops: list .5in;"><span style="font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";">Barn Electricity Use: Barn design will impact energy
use, but around 25 kWh/pig space per year (see Hanna et al., 2016 – Energy
use for field operations, crop drying, and swine housing on University
Farms). Iowa is estimated to generate 0.36 kg N<sub>2</sub>O/MWh and 430.5
kg CO<sub>2</sub>/MWh. These emissions are about 0.5 kg CO<sub>2,e</sub>/kWh,
or 13.5 kg CO<sub>2,e</sub>/head-year.<o:p></o:p></span></li>
<li class="MsoNormal" style="color: #0e101a; line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; mso-list: l3 level1 lfo4; tab-stops: list .5in;"><span style="font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";">Feed production: According to Benavides et al. (2020),
swine feed has about 0.4 kg CO<sub>2,e</sub>/kg feed. If we have a feed
conversion ratio of 2.5 lb feed/lb live weight gain, then 1 kg CO<sub>2,e</sub>/kg
of pig sold. Assuming 2.2 turns a year and 280 lb pigs sold, this results
in 265 kg CO<sub>2,e</sub>/head-year.<o:p></o:p></span></li>
<li class="MsoNormal" style="color: #0e101a; line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; mso-list: l3 level1 lfo4; tab-stops: list .5in;"><span style="font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";">Feed movement: The average freight truck in the U.S.
emits 162 grams of CO<sub>2</sub> per ton-mile. Every pig space needed
0.73 tons of feed/year, and assuming feed was delivered 100 miles gives 12
kg CO<sub>2,e</sub>/head-year.<o:p></o:p></span></li>
<li class="MsoNormal" style="color: #0e101a; line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; mso-list: l3 level1 lfo4; tab-stops: list .5in;"><span style="font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";">Pig movement: Again, assuming 100 miles of pig
transport to the processing plant (finish weight of 280 lb) and 100 miles
from the nursery facility (15 lb wean pig) gives 5.2 kg CO<sub>2,e</sub>/head-year.<o:p></o:p></span></li>
</ol>
<p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; margin-left: .5in; margin-right: 0in; margin-top: 0in;"><span style="color: #0e101a; font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";"><o:p> </o:p></span></p>
<p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><span style="color: #0e101a; font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";">I had a carbon
footprint of 0.5 tons CO<sub>2,e</sub>/pig space per year, or about 2 kg CO<sub>2,e</sub>/kg
live weight produced or 3 CO<sub>2,e</sub>/kg of "take home" meat.
Two caveats, I didn't include the carbon footprint associated with generating
piglets or dealing with mortalities. We can do something easy for mortalities,
like assume a 3% death loss and multiply our results by 3%. Assuming culled
animals used all the feed and generated all the manure they would have if they
were alive, gives a cushion for using energy to handle the carcasses. The
approach raises the lifecycle costs to 0.51 tons CO<sub>2,e</sub>/pig space per
year, and 3.2 CO<sub>2,e</sub>/kg of "take home" meat. Unfortunately,
I don't have a simple trick to deal with generating piglets. To get this
estimate, we need to work on an example sow farm (there is always next time).<o:p></o:p></span></p>
<p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><span style="color: #0e101a; font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";"><o:p> </o:p></span></p>
<p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/a/AVvXsEjSBPd5sxRvtViqBQUiHg0_wpUxDh4_oA4Z1Jl9jiLB4R-UwgyD5gWwjY8QwSVLEYyiDjgz4Bb77mEJtse91djvHQL83nnS1wa5qTYYYnQaXpCSA8Tk7_oviL6zRmlPZC56UVda2vVrx28at6fDADxHVkujAqBkhCrkFgy2UfP9KDR80jbhR3_ENDt0" style="margin-left: 1em; margin-right: 1em;"><img alt="" data-original-height="390" data-original-width="662" height="189" src="https://blogger.googleusercontent.com/img/a/AVvXsEjSBPd5sxRvtViqBQUiHg0_wpUxDh4_oA4Z1Jl9jiLB4R-UwgyD5gWwjY8QwSVLEYyiDjgz4Bb77mEJtse91djvHQL83nnS1wa5qTYYYnQaXpCSA8Tk7_oviL6zRmlPZC56UVda2vVrx28at6fDADxHVkujAqBkhCrkFgy2UfP9KDR80jbhR3_ENDt0" width="320" /></a></div><br /><span style="color: #0e101a; font-family: "Times New Roman", serif; font-size: 12pt;">Figure 1. Percent of
swine finishing greenhouse gas emissions from different sources.</span><p></p>
<p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><span style="color: #0e101a; font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";"><o:p> </o:p></span></p>
<p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><br /></p>
<p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><span style="color: #0e101a; font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";">It's important to note
that achieving carbon neutrality in livestock production will require a
combination of these strategies, and the feasibility of implementation can vary
depending on factors such as location, scale of production, available resources,
and livestock species. Regular assessment, adaptation, and improvement are
necessary to ensure ongoing progress toward carbon neutrality.<o:p></o:p></span></p>Daniel Andersenhttp://www.blogger.com/profile/17296164974381593950noreply@blogger.com0tag:blogger.com,1999:blog-8695306981003495902.post-32338502486110700802022-11-15T10:59:00.002-06:002022-11-15T10:59:39.321-06:00Why is Manure Anaerobic?<p>Manure is stored with one surface in contact with the
atmosphere. That atmosphere contains oxygen. Shouldn’t this oxygen diffuse into
the manure and make it aerobic? And the truth is it does, but often the
diffusion rate is low compared to the rate at which oxygen in the manure is
consumed. As a result, the manure will still be anaerobic. In this month’s
article, we’ll look at oxygen diffusion into the manure and discuss the impact
manure strength and the amount of organic matter in the manure has on how much
of the manure is aerobic.</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal">This analysis is simplified because it doesn’t account for
surface disturbance from wind or mixing in the manure that might spread oxygen
around. That is to say, it is primarily for illustrative purposes and to get a
feel for anaerobic manure storage conditions.<o:p></o:p></p>
<p class="MsoNormal">This analysis works down to two parts understanding oxygen
movement through the manure and the destruction, or use of that oxygen, to
consume organic material. The first part relies on Fick’s law to understand how
oxygen moves in manure. It should be noted that this is based on no mixing.
Mixing drastically changes oxygen movement as it allows for advection, mixing
with the movement of the manure, and diffusion. To get an estimate of just
diffusion-driven oxygen movement in manure, though, I did have to make a couple
of assumptions. The first is that there is a small layer of manure at the
surface with an oxygen content always in equilibrium with the atmosphere. The
second is Fick’s Law and the oxygen diffusion rates in water, which describe
the movement of oxygen in manure.<o:p></o:p></p>
<p class="MsoNormal">The oxygen content of the surface water is estimated using
Henry’s Law and assuming Henry’s constant of <span style="mso-fareast-font-family: "Times New Roman"; mso-fareast-theme-font: minor-fareast;">K<sub>H</sub> = 4.34 x
10<sup>4</sup> atm </span>@ 77<span style="mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin;">°</span>F (25<span style="mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin;">°</span>C). Accepting a partial
pressure of 0.21, based on the 21% oxygen content of the atmosphere, gives, <span style="mso-fareast-font-family: "Times New Roman"; mso-fareast-theme-font: minor-fareast;">4.84 x 10<sup>-6</sup> moles of
oxygen in a mole of water or 4.84 x 10<sup>-6</sup> moles of oxygen in 18 g.
And after a little rearranging and a unit conversion, this amounts to, 4.3 mg/L. </span><span style="mso-fareast-font-family: "Times New Roman"; mso-fareast-theme-font: minor-fareast;">.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-font-family: "Times New Roman"; mso-fareast-theme-font: minor-fareast;">Using this information, Fick’s Law can be
used to estimate diffusion. T</span><span style="mso-fareast-font-family: "Times New Roman"; mso-fareast-theme-font: minor-fareast;">he oxygen diffusion rate in water at </span>77<span style="mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin;">°</span>F
(25<span style="mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin;">°</span>C)
is 2.42 x 10<sup>-9</sup> m<sup>2</sup>/s. The rest of the equation represents
the change in concentration over distance. The change in concentration is 4.3
mg/L since we know the concentration is at a maximum at the surface and goes to
zero, but we aren’t sure over what distance this will occur yet. To help get an
estimate of the distance, we need to think about how quickly the oxygen will be
used.<o:p></o:p></p>
<p class="MsoNormal">Chemical oxygen demand is often measured on different
wastewater materials, including manures, to help understand the strength of the
material. The typical COD of deep pit swine manure is around 100,000 mg/L. About
25% of this will often be BOD<sub>5</sub> (the amount of oxygen bacteria will
consume in five days as they break down organic matter) or 25,000 mg/L.
Assuming that 1/5<sup>th</sup> of the oxygen will be broken down daily, 5,000
mg/L of oxygen will be consumed.<o:p></o:p></p>
<p class="MsoNormal">The solution becomes iterative as we try to guess the depth
that causes all the oxygen to be depleted.<span style="mso-fareast-font-family: "Times New Roman"; mso-fareast-theme-font: minor-fareast;"> To start, assume a 1 m
x 1 m x 1 m deep chunk of liquid manure. The diffusion of oxygen can then be
calculated <span style="mso-spacerun: yes;"> </span>as 0.9 mg/m</span><sup>2</sup>-day.</p>
<p class="MsoNormal"><span style="mso-fareast-font-family: "Times New Roman"; mso-fareast-theme-font: minor-fareast;">How does this compare with the oxygen
demand of the manure? That 1 m x 1 m x 1 m chunk of manure has a 1-day BOD of
5,000,000 mg. Suppose you take the 0.9 mg/m<sup>2</sup>day/ 5,000,000 mg/m<sup>3</sup>day=
0.00000018 m. This gives us our first guess of the depth. The smaller depth
will cause a much higher diffusion rate and lower oxygen demand. We want to
keep iterating this depth process until we find a consistent depth.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-font-family: "Times New Roman"; mso-fareast-theme-font: minor-fareast;">If we iterate this solution, we will find
that the depth to which oxygen diffuses is 5.6 mm, or <o:p></o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-font-family: "Times New Roman"; mso-fareast-theme-font: minor-fareast;">Now iterate the depth you selected in the
diffusion equation until it matches the depth of extinction<o:p></o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-font-family: "Times New Roman"; mso-fareast-theme-font: minor-fareast;">The diffusion depth of oxygen into manure
is 0.42 mm or about 0.02 inches. More than that, that oxygen consumed a tiny amount,
0.00002%, of the oxygen demand.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-font-family: "Times New Roman"; mso-fareast-theme-font: minor-fareast;">In lagoon systems, often the manure is
diluted to help it flow better, but this dilution also helps the lagoon be more
aerobic, at least at the surface. Let’s see what happens if the manure is
diluted by a factor of 5. In this case, about 1 mm would have oxygen or 0.04
inches. Even in this case, diffusion alone has a limited impact on making the
manure aerobic. To help with this, lagoons often have residual material left in
them to help further dilute the manure and to help improve oxygen transfer by
providing a larger surface area. In addition, wave action from wind or surface
aerators or often necessary to make the lagoon aerobic.<o:p></o:p></span></p><p class="MsoNormal">So manure is anaerobic because it has a high capacity to consume oxygen relative to how quickly diffusion allows oxygen to move through the manure.</p>Daniel Andersenhttp://www.blogger.com/profile/17296164974381593950noreply@blogger.com2tag:blogger.com,1999:blog-8695306981003495902.post-56960940116983693892022-09-23T14:23:00.000-05:002022-09-23T14:23:03.975-05:00Anaerobic Digestion – Covered Manure Storages<p> Impermeable covers minimize odor and limit ammonia emissions.
Covers prevent rainfall from mixing with manure, making manure production
volumes more consistent from year to year, reducing the chance of overflow, and
providing the potential for methane capture, reducing the farm's environmental
footprint. These opportunities indicate that covered manure storage should be favored,
yet incorporating impermeable covers has been minimal. Many resources suggest
the potential benefits of impermeable covers, but a thorough economic
evaluation of benefits is lacking, with the existing tools predating the
development of RIN and LCFS Carbon Credit Markets. These markets are
game-changing in the potential opportunities they offer. With this in mind, we
developed a model to estimate how covers would impact the spreading costs, fertilizer
value, biogas production, and carbon credits a farm receives and evaluate
implications for Iowa livestock farms.</p><p class="MsoNormal"><o:p></o:p></p>
<p class="MsoNormal">With that in mind, I've been putting together some estimates
of the value covers and potential costs. Many assumptions are involved in these
estimates, and hopefully, a future extension publication will walk through some
of the calculations. Here we provide a comprehensive economic exploration of
the value impermeable covers offer, focused on illustrating both perceived
values and those that are the definitive economic drivers in the current
marketplace. We looked at three example farms, a 4800-head swine finishing farm
starting with deep pit manure storage, a 4800-head swine finishing farm
starting with a drain pit and out-of-barn slurry storage, and a 500-head dairy
with out-of-barn manure storage. We calculated the cost of modifying the
facility to add a cover at each farm and the potential cost savings provided
with current economic and carbon credit-based incentives. Evaluations assumed a
5-year or 10-year life with interest set at 8%.<o:p></o:p></p>
<p class="MsoNormal">Results are shown in table 1. In general, when all potential
values are considered, both the 4800 head swine and the 500 head dairy using
lagoon, earthen basin, or out-of-barn manure storage were cost feasible within
five years and had net annual incomes of $50,000-$70,000 within five years.
Economics didn't appear as favorable at deep pit facilities as construction
costs for manure storage modifications increased cost. Combined with a higher
carbon intensity score on methane, this produced limited payback opportunities.<o:p></o:p></p>
<p align="center" class="MsoNormal" style="text-align: center;">Table 1. Estimated
cost-benefit ratio for covers at livestock facilities creating CNG.<o:p></o:p></p>
<div align="right">
<table border="0" cellpadding="0" cellspacing="0" class="MsoNormalTable" style="border-collapse: collapse; mso-padding-alt: 0in 5.4pt 0in 5.4pt; mso-yfti-tbllook: 1184; width: 582px;">
<tbody><tr style="height: 15.0pt; mso-yfti-firstrow: yes; mso-yfti-irow: 0;">
<td nowrap="" style="border-top: solid windowtext 1.0pt; border: none; height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 2.25in;" width="216">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";"> <o:p></o:p></span></p>
</td>
<td colspan="3" style="border-top: solid windowtext 1.0pt; border: none; height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 2.0in;" width="192">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">5-year
life<o:p></o:p></span></p>
</td>
<td colspan="3" style="border-top: solid windowtext 1.0pt; border: none; height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 130.5pt;" width="174">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">10-year
life<o:p></o:p></span></p>
</td>
</tr>
<tr style="height: 15.0pt; mso-yfti-irow: 1;">
<td nowrap="" rowspan="2" style="border-bottom: double black 2.25pt; border: none; height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 2.25in;" width="216">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">Facility
Type<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">4800
swine<o:p></o:p></span></p>
</td>
<td style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">4800
swine<o:p></o:p></span></p>
</td>
<td nowrap="" rowspan="2" style="border-bottom: double black 2.25pt; border: none; height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 45.0pt;" width="60">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">500
head dairy<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">4800
swine<o:p></o:p></span></p>
</td>
<td style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">4800
swine<o:p></o:p></span></p>
</td>
<td nowrap="" rowspan="2" style="border-bottom: double black 2.25pt; border: none; height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 31.5pt;" width="42">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">500
head dairy<o:p></o:p></span></p>
</td>
</tr>
<tr style="height: 15.75pt; mso-yfti-irow: 2;">
<td nowrap="" style="border-bottom: double windowtext 2.25pt; border: none; height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">deep
pit<o:p></o:p></span></p>
</td>
<td style="border-bottom: double windowtext 2.25pt; border: none; height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">lagoon<o:p></o:p></span></p>
</td>
<td nowrap="" style="border-bottom: double windowtext 2.25pt; border: none; height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">deep
it<o:p></o:p></span></p>
</td>
<td style="border-bottom: double windowtext 2.25pt; border: none; height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">lagoon<o:p></o:p></span></p>
</td>
</tr>
<tr style="height: 15.75pt; mso-yfti-irow: 3;">
<td nowrap="" style="height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 2.25in;" width="216">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">Methane
Value<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$44,661
<o:p></o:p></span></p>
</td>
<td style="height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$44,661
<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 45.0pt;" width="60">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$44,030
<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$44,661
<o:p></o:p></span></p>
</td>
<td style="height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$44,661
<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 31.5pt;" width="42">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$44,030
<o:p></o:p></span></p>
</td>
</tr>
<tr style="height: 15.0pt; mso-yfti-irow: 4;">
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 2.25in;" width="216">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">LCFS
Value<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$199,352
<o:p></o:p></span></p>
</td>
<td style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$420,744
<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 45.0pt;" width="60">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$414,804
<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$199,352
<o:p></o:p></span></p>
</td>
<td style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$420,744
<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 31.5pt;" width="42">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$414,804
<o:p></o:p></span></p>
</td>
</tr>
<tr style="height: 15.0pt; mso-yfti-irow: 5;">
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 2.25in;" width="216">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">RIN
Value<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$283,311
<o:p></o:p></span></p>
</td>
<td style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$283,311
<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 45.0pt;" width="60">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$279,312
<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$283,311
<o:p></o:p></span></p>
</td>
<td style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$283,311
<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 31.5pt;" width="42">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$279,312
<o:p></o:p></span></p>
</td>
</tr>
<tr style="height: 15.75pt; mso-yfti-irow: 6;">
<td nowrap="" style="height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 2.25in;" width="216">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">Nitrogen
Value Savings<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$5,635
<o:p></o:p></span></p>
</td>
<td style="height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$4,827
<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 45.0pt;" width="60">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$2,401
<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$5,635
<o:p></o:p></span></p>
</td>
<td style="height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$4,827
<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 31.5pt;" width="42">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$2,401
<o:p></o:p></span></p>
</td>
</tr>
<tr style="height: 15.0pt; mso-yfti-irow: 7;">
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 2.25in;" width="216">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">Odor
Reduction<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$6,900
<o:p></o:p></span></p>
</td>
<td style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$6,900
<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 45.0pt;" width="60">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$884
<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$6,900
<o:p></o:p></span></p>
</td>
<td style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$6,900
<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 31.5pt;" width="42">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$884
<o:p></o:p></span></p>
</td>
</tr>
<tr style="height: 15.0pt; mso-yfti-irow: 8;">
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 2.25in;" width="216">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">Storage
Construction Savings<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$0
<o:p></o:p></span></p>
</td>
<td style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$1,226
<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 45.0pt;" width="60">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$2,427
<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$0
<o:p></o:p></span></p>
</td>
<td style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$729
<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 31.5pt;" width="42">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$1,444
<o:p></o:p></span></p>
</td>
</tr>
<tr style="height: 15.0pt; mso-yfti-irow: 9;">
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 2.25in;" width="216">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">Manure
Application Costs<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: red; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">($2,674)</span><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";"><o:p></o:p></span></p>
</td>
<td style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$398
<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 45.0pt;" width="60">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$2,845
<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: red; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">($2,674)</span><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";"><o:p></o:p></span></p>
</td>
<td style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$398
<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 31.5pt;" width="42">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$2,845
<o:p></o:p></span></p>
</td>
</tr>
<tr style="height: 15.75pt; mso-yfti-irow: 10;">
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 2.25in;" width="216">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">Carbon
Credits from N<sub>2</sub>O<o:p></o:p></span></p>
</td>
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: red; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">($770)</span><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";"><o:p></o:p></span></p>
</td>
<td style="border-bottom: solid windowtext 1.0pt; border: none; height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: red; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">($2,690)</span><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";"><o:p></o:p></span></p>
</td>
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 45.0pt;" width="60">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$554
<o:p></o:p></span></p>
</td>
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: red; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">($770)</span><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";"><o:p></o:p></span></p>
</td>
<td style="border-bottom: solid windowtext 1.0pt; border: none; height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: red; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">($2,690)</span><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";"><o:p></o:p></span></p>
</td>
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 31.5pt;" width="42">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$554
<o:p></o:p></span></p>
</td>
</tr>
<tr style="height: 15.0pt; mso-yfti-irow: 11;">
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 2.25in;" width="216">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">Pipeline
Injection Point<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$250,457
<o:p></o:p></span></p>
</td>
<td style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$250,457
<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 45.0pt;" width="60">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$250,457
<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$149,029
<o:p></o:p></span></p>
</td>
<td style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$149,029
<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 31.5pt;" width="42">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$149,029
<o:p></o:p></span></p>
</td>
</tr>
<tr style="height: 15.0pt; mso-yfti-irow: 12;">
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 2.25in;" width="216">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">Biogas
Cleaning & Compression Equipment<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$186,254
<o:p></o:p></span></p>
</td>
<td style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$186,254
<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 45.0pt;" width="60">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$183,624
<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$110,827
<o:p></o:p></span></p>
</td>
<td style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$110,827
<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 31.5pt;" width="42">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$109,262
<o:p></o:p></span></p>
</td>
</tr>
<tr style="height: 15.75pt; mso-yfti-irow: 13;">
<td nowrap="" style="height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 2.25in;" width="216">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">Biogas
Cleaning & Compression Maintenance<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$74,366
<o:p></o:p></span></p>
</td>
<td style="height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$74,366
<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 45.0pt;" width="60">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$73,316
<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$74,366
<o:p></o:p></span></p>
</td>
<td style="height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$74,366
<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 31.5pt;" width="42">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$73,316
<o:p></o:p></span></p>
</td>
</tr>
<tr style="height: 15.0pt; mso-yfti-irow: 14;">
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 2.25in;" width="216">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">Biogas
Cleaning Operation<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$11,018
<o:p></o:p></span></p>
</td>
<td style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$11,018
<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 45.0pt;" width="60">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$10,862
<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$11,018
<o:p></o:p></span></p>
</td>
<td style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$11,018
<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 31.5pt;" width="42">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$10,862
<o:p></o:p></span></p>
</td>
</tr>
<tr style="height: 15.0pt; mso-yfti-irow: 15;">
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 2.25in;" width="216">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">Biogas
Management Employee<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$80,000
<o:p></o:p></span></p>
</td>
<td style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$80,000
<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 45.0pt;" width="60">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$80,000
<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$80,000
<o:p></o:p></span></p>
</td>
<td style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$80,000
<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 31.5pt;" width="42">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$80,000
<o:p></o:p></span></p>
</td>
</tr>
<tr style="height: 15.0pt; mso-yfti-irow: 16;">
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 2.25in;" width="216">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">LCFS/RIN
Sales Fees (10%)<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$48,266
<o:p></o:p></span></p>
</td>
<td style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$70,405
<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 45.0pt;" width="60">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$69,412
<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$48,266
<o:p></o:p></span></p>
</td>
<td style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$70,405
<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 31.5pt;" width="42">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$69,412
<o:p></o:p></span></p>
</td>
</tr>
<tr style="height: 15.0pt; mso-yfti-irow: 17;">
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 2.25in;" width="216">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">Manure
Storage Construction<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$102,391
<o:p></o:p></span></p>
</td>
<td style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$0
<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 45.0pt;" width="60">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$0
<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$60,926
<o:p></o:p></span></p>
</td>
<td style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$0
<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 31.5pt;" width="42">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$0
<o:p></o:p></span></p>
</td>
</tr>
<tr style="height: 15.0pt; mso-yfti-irow: 18;">
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 2.25in;" width="216">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">Annualized
Cover Installation Cost<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$13,948
<o:p></o:p></span></p>
</td>
<td style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$13,948
<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 45.0pt;" width="60">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$22,126
<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$8,300
<o:p></o:p></span></p>
</td>
<td style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$8,300
<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 31.5pt;" width="42">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$13,166
<o:p></o:p></span></p>
</td>
</tr>
<tr style="height: 15.0pt; mso-yfti-irow: 19;">
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 2.25in;" width="216">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">Cover
Maintenance Cost<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$5,569
<o:p></o:p></span></p>
</td>
<td style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$5,569
<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 45.0pt;" width="60">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$8,834
<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$5,569
<o:p></o:p></span></p>
</td>
<td style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$5,569
<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 31.5pt;" width="42">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$8,834
<o:p></o:p></span></p>
</td>
</tr>
<tr style="height: 15.75pt; mso-yfti-irow: 20;">
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 2.25in;" width="216">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">Rainfall
Removal<o:p></o:p></span></p>
</td>
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$14
<o:p></o:p></span></p>
</td>
<td style="border-bottom: solid windowtext 1.0pt; border: none; height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$14
<o:p></o:p></span></p>
</td>
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 45.0pt;" width="60">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$28
<o:p></o:p></span></p>
</td>
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$14
<o:p></o:p></span></p>
</td>
<td style="border-bottom: solid windowtext 1.0pt; border: none; height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$14
<o:p></o:p></span></p>
</td>
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 31.5pt;" width="42">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$28
<o:p></o:p></span></p>
</td>
</tr>
<tr style="height: 15.0pt; mso-yfti-irow: 21;">
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 2.25in;" width="216">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><i><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">Annual
Benefit<o:p></o:p></span></i></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><i><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$536,415
<o:p></o:p></span></i></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><i><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$759,377
<o:p></o:p></span></i></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 45.0pt;" width="60">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><i><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$747,257
<o:p></o:p></span></i></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><i><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$536,415
<o:p></o:p></span></i></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><i><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$758,880
<o:p></o:p></span></i></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 31.5pt;" width="42">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><i><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$746,274
<o:p></o:p></span></i></p>
</td>
</tr>
<tr style="height: 15.0pt; mso-yfti-irow: 22;">
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 2.25in;" width="216">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><i><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">Annual
Expense<o:p></o:p></span></i></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><i><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$772,283
<o:p></o:p></span></i></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><i><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$692,031
<o:p></o:p></span></i></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 45.0pt;" width="60">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><i><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$698,659
<o:p></o:p></span></i></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><i><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$548,315
<o:p></o:p></span></i></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><i><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$509,528
<o:p></o:p></span></i></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 31.5pt;" width="42">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><i><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$513,909
<o:p></o:p></span></i></p>
</td>
</tr>
<tr style="height: 15.75pt; mso-yfti-irow: 23; mso-yfti-lastrow: yes;">
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 2.25in;" width="216">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><i><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">Net
Benefit<o:p></o:p></span></i></p>
</td>
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><i><span style="color: red; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">($235,868)</span></i><i><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";"><o:p></o:p></span></i></p>
</td>
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><i><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$67,346
<o:p></o:p></span></i></p>
</td>
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 45.0pt;" width="60">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><i><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$48,598
<o:p></o:p></span></i></p>
</td>
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><i><span style="color: red; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">($11,900)</span></i><i><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";"><o:p></o:p></span></i></p>
</td>
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><i><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$249,352
<o:p></o:p></span></i></p>
</td>
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 31.5pt;" width="42">
<p align="center" class="MsoNormal" style="line-height: normal; text-align: center;"><i><span style="color: black; font-size: 8.0pt; mso-fareast-font-family: "Times New Roman";">$232,365
<o:p></o:p></span></i></p>
</td>
</tr>
</tbody></table>
</div>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">These results are highly dependent on a farm scale and
assumed covered manure storage, not the implementation of an anaerobic
digester. Next month we'll look closely at the role farm size plays. In
November we'll look at how heated digester systems compare to impermeable
covers.<o:p></o:p></p>Daniel Andersenhttp://www.blogger.com/profile/17296164974381593950noreply@blogger.com0tag:blogger.com,1999:blog-8695306981003495902.post-90739821875267115212022-08-05T14:52:00.003-05:002022-08-05T14:52:33.903-05:00Impact of Manure Timing on Effective Nitrogen Supply<p> Nitrogen use efficiency (NUE) is the dry mass productivity per unit N taken up from the soil. The term can be used in many complex ways to illustrate different factors, like the amount of nitrogen supplied from the soil.</p><p><br /></p><p>I looked at applied nitrogen (from liquid swine manure) as a function of manure application timing and crop yield response. At Nashua, Iowa, we have four years of data looking at manure application timing. Treatments were early fall (October), late fall (November), and spring. We’ve presented this data as the difference in yield. Here, I look at it a different way; how effective was the application in supplying nitrogen?</p><p><br /></p><p>The process to estimate how effective the nitrogen was at supplying the crop was:</p><p>1. Use the difference in yield between the treatments to estimate the percent of maximum yield.</p><p>2. Use the Iowa State Maximum Return to Nitrogen nitrogen response curve to estimate effective nitrogen supply.</p><p>The results are plotted in figure 1.</p><p><br /></p><p>So what does this mean? The spring manure achieved 99% of the maximum yield. It has the same yield as the spring applied UAN. The late fall manure yielded around 85% of the maximum yield. The early fall manure yielded 65% of the maximum yield. Reading from the x-axis provides an effective nitrogen supply.</p><p><br /></p><p>The spring application, by default, supplied approximately 150 lb N/acre (as it is used as the baseline). The late fall application had a yield equivalent to 75 lb N/acre in the spring. The early fall manure had a yield equivalent to if only 25 lb N/acre had been applied. This means that the late fall manure was only taking advantage of about 50% of the nitrogen applied. The early fall manure was only 17% effective. These numbers illustrate the important role application timing plays in using manure</p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEidarrKODjen_IWtvXX4gLJ5_vaAHERR2qtEufxo_Kj2Zopukrw_S-RdpR5upcHMYyIMoHJmnbvx_Ee9GuOA1Y2FZKUUD-Xcp0uO_PP-JJzWgfMG74Pr74Z2inUwe8ROjZ6ROUp9mVWPHFAvVBn6S-0t9aJhtWfE_Lu7qzuEugatKkTiPGCT-rhvrks/s480/NUE.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="288" data-original-width="480" height="192" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEidarrKODjen_IWtvXX4gLJ5_vaAHERR2qtEufxo_Kj2Zopukrw_S-RdpR5upcHMYyIMoHJmnbvx_Ee9GuOA1Y2FZKUUD-Xcp0uO_PP-JJzWgfMG74Pr74Z2inUwe8ROjZ6ROUp9mVWPHFAvVBn6S-0t9aJhtWfE_Lu7qzuEugatKkTiPGCT-rhvrks/s320/NUE.png" width="320" /></a></div><p>Figure 1. Effective nitrogen application rate from EFM (Early Fall Manure), LFM (Late Fall Manure), and SM (Spring Manure) when all were applied at 150 lb available N/acre at the time of application.</p>Daniel Andersenhttp://www.blogger.com/profile/17296164974381593950noreply@blogger.com2tag:blogger.com,1999:blog-8695306981003495902.post-37234475014509100392022-07-18T11:56:00.005-05:002022-07-18T11:56:59.045-05:00Carbon Footprint and the Frequency of Manure Removal<p><span style="color: #1f497d; font-size: 11pt;">Carbon footprints have become
important topics for sustainability. In pursuit of carbon neutrality, many
technologies are promoted. Some require large capital investment or changes to
a farm’s infrastructure. For example, adding aeration to existing manure
storage. Or adding capturing biogas capture and cleaning to make renewable
methane. But not all practices that reduce a farm’s greenhouse gas emissions must
be so complicated. More frequent manure applications can also reduce greenhouse
gas emissions.</span></p>
<p class="MsoNormal"><span style="color: #1f497d; font-size: 11.0pt; mso-ascii-font-family: Calibri; mso-bidi-font-family: Calibri; mso-fareast-font-family: "Times New Roman"; mso-hansi-font-family: Calibri;"> </span><span style="color: #1f497d; font-size: 11pt;">Manure methane production is
proportional to methane potential and percent conversion during storage. The
potential depends on the ration fed and completeness of digestion in the
animal. The percent conversion is based on the storage length and temperature.
Higher temperatures, or longer storage times, lead to greater conversion.</span></p>
<p class="MsoNormal"><span style="color: #1f497d; font-size: 11.0pt; mso-ascii-font-family: Calibri; mso-bidi-font-family: Calibri; mso-fareast-font-family: "Times New Roman"; mso-hansi-font-family: Calibri;"> </span><span style="color: #1f497d; font-size: 11pt;">In 2015 I wrote a paper exploring
methane production from deep pit manure storage. I examined how temperature,
volume, and properties influenced biological activity. Using this information,
I put together a model to estimate how much methane a pig space produced per
year. I use this model to explore how different application strategies impact
methane emissions.</span></p>
<p class="MsoNormal"><span style="color: #1f497d; font-size: 11.0pt; mso-ascii-font-family: Calibri; mso-bidi-font-family: Calibri; mso-fareast-font-family: "Times New Roman"; mso-hansi-font-family: Calibri;"> A</span><span style="color: #1f497d; font-size: 11pt;">ssume the base case will be a
swine finishing operation that land applies manure once per year in the fall.
Let the initial manure depth be 30.5 cm in November. Each pig has 0.9 m</span><sup style="color: #1f497d;">2</sup><span style="color: #1f497d; font-size: 11pt;">
of floor space and generates 4.9 L/headspace-day of manure at 9% solids. The
methane production rate would be estimated at 0.0996 L CH</span><sub style="color: #1f497d;">4</sub><span style="color: #1f497d; font-size: 11pt;">/L-day.
The annual methane emission is 19 kg CH</span><sub style="color: #1f497d;">4</sub><span style="color: #1f497d; font-size: 11pt;">/animal space-year.</span></p>
<p class="MsoNormal"><span style="color: #1f497d; font-size: 11.0pt; mso-ascii-font-family: Calibri; mso-bidi-font-family: Calibri; mso-fareast-font-family: "Times New Roman"; mso-hansi-font-family: Calibri;"> </span><span style="color: #1f497d; font-size: 11pt;">How would switching to twice a year
manure application alter this estimate? Using the same assumption, adding
manure removal in May would reduce the estimated methane emission to 10 kg CH</span><sub style="color: #1f497d;">4</sub><span style="color: #1f497d; font-size: 11pt;">/animal
space-year. This is a 46% reduction.</span></p>
<p class="MsoNormal"><span style="color: #1f497d; font-size: 11.0pt; mso-ascii-font-family: Calibri; mso-bidi-font-family: Calibri; mso-fareast-font-family: "Times New Roman"; mso-hansi-font-family: Calibri;"> </span><span style="color: #1f497d; font-size: 11pt;">These calculations assume no change
in nitrogen use efficiency. Making synthetic nitrogen is energy intensive.
Thus, our ability to use manure as a fertilizer is important to our greenhouse
gas footprint. Our work with spring manure has shown that it can be a method to
increase nitrogen use efficiency.</span></p>
<p class="MsoNormal"><span style="color: #1f497d; font-size: 11.0pt; mso-ascii-font-family: Calibri; mso-bidi-font-family: Calibri; mso-fareast-font-family: "Times New Roman"; mso-hansi-font-family: Calibri;"> </span><span style="color: #1f497d; font-size: 11pt;">New technologies, like in-season
manure application, may further reduce methane emissions. This model suggests
that applying in spring, summer, and fall might result in a 70% reduction.</span></p>
<p class="MsoNormal"><span style="color: #1f497d; font-size: 11.0pt; mso-ascii-font-family: Calibri; mso-bidi-font-family: Calibri; mso-fareast-font-family: "Times New Roman"; mso-hansi-font-family: Calibri;"> </span><span style="color: #1f497d; font-size: 11pt;">So, what does this mean? California
offers a carbon offset market at approximately $30 a ton per CO</span><sub style="color: #1f497d;">2</sub><span style="color: #1f497d; font-size: 11pt;">
equivalent. At this price, going from once a year to twice a year manure
application would reduce emissions by 225 kg CO</span><sub style="color: #1f497d;">2</sub><span style="color: #1f497d; font-size: 11pt;"> per pig space. This
is worth about $6 a pig space. Similarly, going to an in-season application
would be worth about $10 per pig space.</span></p>
<p class="MsoNormal"><span style="color: #1f497d; font-size: 11.0pt; mso-ascii-font-family: Calibri; mso-bidi-font-family: Calibri; mso-fareast-font-family: "Times New Roman"; mso-hansi-font-family: Calibri;"> </span><span style="color: #1f497d; font-size: 11pt;">At 5,000 pig sites, around $50,000
a year in potential revenue. This revenue could help buy new equipment or pay
labor to make such changes achievable.</span></p>Daniel Andersenhttp://www.blogger.com/profile/17296164974381593950noreply@blogger.com0tag:blogger.com,1999:blog-8695306981003495902.post-24181456252625083602022-05-31T15:25:00.003-05:002022-05-31T15:25:51.184-05:00Carbon Corner – Manure Aeration<p> </p><p class="MsoNormal">Carbon has become an essential topic in
agriculture through the Renewable Fuels Standard, Low Carbon Fuel Standard, and,
more recently, through voluntary carbon markets and sustainability pledges
within agriculture. These efforts allow either marketing of products as
sustainable or the sale of carbon offsets through trading markets. While most agricultural
carbon markets have focused on carbon storage within the soil, at some point,
manure management that limits greenhouse gas emissions may be able to generate
these credits.</p>
<p class="MsoNormal" style="background: white; line-height: normal; mso-margin-bottom-alt: auto; mso-margin-top-alt: auto; vertical-align: baseline;"><span style="color: black; mso-ascii-font-family: Calibri; mso-bidi-font-family: Calibri; mso-fareast-font-family: "Times New Roman"; mso-hansi-font-family: Calibri;">In the
area of manure, several factors can impact our carbon footprint. Generally,
methane and nitrous oxide emissions are the driving factors. Carbon dioxide (CO<sub><span style="border: none windowtext 1.0pt; mso-border-alt: none windowtext 0in; padding: 0in;">2</span></sub>) released from manure is biogenic. Recently,
atmospheric carbon was transformed to plant material and then into atmospheric
CO<sub><span style="border: none windowtext 1.0pt; mso-border-alt: none windowtext 0in; padding: 0in;">2, </span></sub>where it stays a part of the active carbon
cycle. Therefore, it is not included as a greenhouse gas.<o:p></o:p></span></p>
<p class="MsoNormal" style="background: white; line-height: normal; mso-margin-bottom-alt: auto; mso-margin-top-alt: auto; vertical-align: baseline;"><span style="color: black; mso-ascii-font-family: Calibri; mso-bidi-font-family: Calibri; mso-fareast-font-family: "Times New Roman"; mso-hansi-font-family: Calibri;">One
option currently receiving attention is the aeration of liquid manure.
Typically, liquid manures create anaerobic conditions as they have high
biological oxygen demand that consumes the oxygen at a rate greater than it can
diffuse from the surface. In these anaerobic conditions, as the bacteria eat
the organic matter within the manure, they make methane, carbon dioxide,
ammonia, hydrogen sulfide, and numerous volatile organic compounds. These
volatile organic compounds are typically responsible for the odors we associate
with manure. In aeration systems, we try to supply enough oxygen to maintain
aerobic conditions. In aerobic conditions, the decomposition of organic matter
will result in the formation of carbon dioxide, water, and microbial cells. <o:p></o:p></span></p>
<p class="MsoNormal" style="background: white; line-height: normal; mso-margin-bottom-alt: auto; mso-margin-top-alt: auto; vertical-align: baseline;"><span style="color: black; mso-ascii-font-family: Calibri; mso-bidi-font-family: Calibri; mso-fareast-font-family: "Times New Roman"; mso-hansi-font-family: Calibri;">A deep
pit swine manure storage will emit around 12 kg CH<sub>4</sub> per headspace
per year under Iowa conditions and 36.2 kg of CO<sub>2</sub>. In this system,
341 kg CO<sub>2</sub> equivalents per pig space per year are emitted. Aeration
systems can reduce or eliminate this methane emission and instead emit it as CO<sub>2</sub>.
Assuming the same amount of organic matter would be degraded under the aerobic
system, only 70 kg CO<sub>2 </sub>would be emitted, or a savings of 270 kg CO<sub>2</sub>
per headspace per year. To estimate the value of a current carbon market, the
California Carbon Allowance has a carbon price of around $30 a metric ton. This
means the value of a carbon credit would be approximately $8.14 per pig space
per year minus whatever energy is used to aerate the manure.<o:p></o:p></span></p>
<p class="MsoNormal" style="background: white; line-height: normal; mso-margin-bottom-alt: auto; mso-margin-top-alt: auto; vertical-align: baseline;"><span style="color: black; mso-ascii-font-family: Calibri; mso-bidi-font-family: Calibri; mso-fareast-font-family: "Times New Roman"; mso-hansi-font-family: Calibri;">Aeration
can be achieved from either natural aeration or mechanical aeration. Natural
aeration requires large, shallow storage that generally has some dilution water
or residual storage volume to help reduce the concentrations of the wastewater
to help match oxygen diffusion to oxygen demand for the liquid. In some cases,
it may not be possible for the entire storage to be aerobic, but the design
should facilitate aerobic conditions near the surface, which effectively
reduces odor emissions. This option has the advantage of needing little energy
but often requires large areas of land. Alternatively, aeration can be done
mechanically by blowing bubbles into the air or causing surface splashing to
encourage oxygen diffusion into the manure.<o:p></o:p></span></p>
<p class="MsoNormal" style="background: white; line-height: normal; mso-margin-bottom-alt: auto; mso-margin-top-alt: auto; vertical-align: baseline;"><span style="color: black; mso-ascii-font-family: Calibri; mso-bidi-font-family: Calibri; mso-fareast-font-family: "Times New Roman"; mso-hansi-font-family: Calibri;">To
eliminate methane production from the manure, full aeration is probably
required. Partial aeration can provide mixing and some reduction in methane
production, but more research is required to determine how aeration amount
reduces methane production. A finishing pig produces about 0.27 kg oxygen
demand per day for complete aeration (on average, it will vary with pig size
and diet-fed), or 100 kg per year per pig. A typical oxygen transfer rate for
mechanical aerators is around 1.2 to 2.1 kg oxygen per kilowatt-hour of energy
used. Assuming we’ll get 1.65 kg oxygen per kilowatt-hour of energy used, we’d
need 60 kW-hrs of energy per pig space per year. At an electricity price of
$0.10 per kWh this amounts to $6 per pig a year. On average, US electricity
emits 0.85 lb of CO<sub>2</sub> per kWh consumed. Adding this added electricity
use into our carbon budget, the aerated manure would release 93 kg of CO<sub>2,</sub>
as compared to the 341 kg from the stored manure. Assuming a spot market of
around $30 per ton of CO2, this would be an annual net asset to the farm of
$1.50 per pig space. This would have to pay for the initial equipment.<o:p></o:p></span></p>
<p class="MsoNormal" style="background: white; line-height: normal; mso-margin-bottom-alt: auto; mso-margin-top-alt: auto; vertical-align: baseline;"><span style="color: black; mso-ascii-font-family: Calibri; mso-bidi-font-family: Calibri; mso-fareast-font-family: "Times New Roman"; mso-hansi-font-family: Calibri;">This
illustrates that moving forward, carbon markets are and will continue to be a
key driver in how manure management systems evolve.<o:p></o:p></span></p>Daniel Andersenhttp://www.blogger.com/profile/17296164974381593950noreply@blogger.com0tag:blogger.com,1999:blog-8695306981003495902.post-63857154371116160122022-04-15T11:25:00.002-05:002022-04-15T11:25:33.727-05:00Manure Management and Biosecurity<p> </p><p class="MsoNormal"><span style="color: #0e101a; font-family: "Times New Roman",serif; mso-fareast-font-family: "Times New Roman";">The prevention of disease transfers due to
manure handling equipment moving from one farm to the next is essential for
your operation. Biosecurity advice often revolves around owning your pumping
equipment dedicated to your farm. It also ensures manure equipment was washed,
disinfected, and in some cases, had a “downtime” before moving to the following
site. These techniques still hold today, but new ideas and innovations have
made biosecurity more convenient.</span><span style="color: black; font-family: "Times New Roman",serif; mso-fareast-font-family: "Times New Roman";"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="color: #0e101a; font-family: "Times New Roman",serif; mso-fareast-font-family: "Times New Roman";"> </span><span style="color: #0e101a; font-family: "Times New Roman", serif;">Owning your manure pumping and handling
equipment still provides the most biosecure option. It gives complete control
over what sites the equipment has been on, how recently it was cleaned and disinfected,
and the amount of downtime before it is used.</span></p>
<p class="MsoNormal"><span style="color: #0e101a; font-family: "Times New Roman",serif; mso-fareast-font-family: "Times New Roman";"> </span><span style="color: #0e101a; font-family: "Times New Roman", serif;">When working with custom manure haulers, make
them aware of any biosecurity requirements for your farm upfront. Please take a
moment to inspect their equipment as they arrive to make sure it is clean. Try
to work with them to provide cleaning and disinfecting options as they finish
your site—review lines of separation and routes through the farm site to
maintain biosecurity. Be clear about the health status of a facility. As custom
applicators organize their jobs, they can ensure proper biosecurity is
maintained. Work from farms with the highest to lowest biosecurity requirements
and current health status. Switch the feces species you are hauling as the risk
of disease transfer between different livestock is typically lower; when
possible, add a cattle job between pig sites.</span></p>
<p class="MsoNormal"><span style="color: #0e101a; font-family: "Times New Roman",serif; mso-fareast-font-family: "Times New Roman";"> </span><span style="color: #0e101a; font-family: "Times New Roman", serif;">However, we have also seen equipment changes help
make manure withdrawal more biosecure. One challenge with maintaining
biosecurity of manure removal is removing a pump-out cover from the barn and
dropping an agitator into the manure. The pump-out opening modifies the
ventilation system. It often serves as an air inlet; in filtered barns, this
weakens biosecurity as </span><span style="color: #0e101a; font-family: "Times New Roman", serif;"> </span><span style="color: #0e101a; font-family: "Times New Roman", serif;">air isn’t forced
through the filter before entering the pig space. As a result, some farms have
begun to switch to a straw or a “mass agitation” system. Rather than opening a
pump out cover, the manure pump is hooked directly to the straws built into the
pump-out lid to recycle manure back into the barn and one port for manure
removal.</span></p>
<p class="MsoNormal"><span style="color: #0e101a; font-family: "Times New Roman",serif; mso-fareast-font-family: "Times New Roman";"> </span><span style="color: #0e101a; font-family: "Times New Roman", serif;">In addition to often being the weak link in
terms of maintaining the integrity of the barn ventilation system, the drop-in
agitation pump is often the hardest to clean and disinfect. These systems, with
manure straws, allow pump trailers to be pulled alongside the barn and speed
cleaning and disinfecting as because they are not lowered into the manure, they
stay cleaner.</span></p>
<p class="MsoNormal"><span style="color: #0e101a; font-family: "Times New Roman",serif; mso-fareast-font-family: "Times New Roman";"> </span><span style="color: #0e101a; font-family: "Times New Roman", serif;">An alternative option is to use a pump dedicated
to the site to move the load station further away from the building, making
maintaining lines of separation much more straightforward. In this way,
tractors and tanks have greater maneuverability. There is less risk of manure
haulers and farmworkers crossing paths and inadvertently contaminating the
clean side of a clean/dirty line. Similarly, the farm site provides the lead
pump and a short distance of hose dedicated to the facility when using the
dragline application. In this case, it is vital to ensure that the pumping
capacity of the supplied lead pump and the rest of the pump system align.</span></p>
<p class="MsoNormal" style="text-align: center;"><span style="color: #0e101a; font-family: "Times New Roman",serif; mso-fareast-font-family: "Times New Roman";"><o:p> </o:p></span></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEizP6KRBs7FE1IQtPKcIMiEfklBztUXHgTm3WQeNR71zggKhGp3jsMdgm2uQ-QD-6mb-0TIqPmUpUieTMkrmgCZoGFANYZfpGce3vBlm1j7ERLAjLv_V2FiAWRwOnelaKy9xns3JDn2He2RD-NKjhGbWg0VI49DYmVO9CmvCVkN6cyoo9O2iWu1N3fM/s399/pumpstation.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="299" data-original-width="399" height="240" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEizP6KRBs7FE1IQtPKcIMiEfklBztUXHgTm3WQeNR71zggKhGp3jsMdgm2uQ-QD-6mb-0TIqPmUpUieTMkrmgCZoGFANYZfpGce3vBlm1j7ERLAjLv_V2FiAWRwOnelaKy9xns3JDn2He2RD-NKjhGbWg0VI49DYmVO9CmvCVkN6cyoo9O2iWu1N3fM/s320/pumpstation.jpg" width="320" /></a></div><p></p><p class="MsoNormal"></p><p align="center" class="MsoNormal" style="text-align: center;"><span style="color: black; font-size: 10.0pt; mso-ascii-font-family: Calibri; mso-bidi-font-family: Calibri; mso-fareast-font-family: "Times New Roman"; mso-hansi-font-family: Calibri;">Figure 1. The load station is located away from the facility and
in the field to help maintain lines of separation.<o:p></o:p></span></p><span style="color: #0e101a; font-family: "Times New Roman",serif; mso-fareast-font-family: "Times New Roman";"><o:p></o:p></span><p></p>Daniel Andersenhttp://www.blogger.com/profile/17296164974381593950noreply@blogger.com0tag:blogger.com,1999:blog-8695306981003495902.post-39553150714140239722022-03-14T12:17:00.004-05:002022-03-14T12:17:37.767-05:00Higher Fertilizer Prices, Manure Opportunities<p> </p><p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">Last
fall, fertilizer prices were trending higher (Figure 1), and with supply change
issues and soaring fuel prices, that trend has continued into the spring. Even
with potentially higher crop prices, this offers challenges to finding ways to
increase or maintain farm profitability. However, one available option is to
explore the use of manure on your farm. Many livestock owners have long known
the value manure has to offer. With skyrocketing commercial fertilizer prices,
this offers the opportunity to make even better use of the manure resources.<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;"><o:p> </o:p></span></p>
<div style="margin-left: 1em; margin-right: 1em; text-align: center;"><a href="https://blogger.googleusercontent.com/img/a/AVvXsEjLLKbLGWnTgyVGqo_tkwNu7NLbgZDd23_WhQtcjGYfqQeEoctjSsr-vKK-yQ55RinHxfPHGkA_kQcVBxtIPs85bG9tuJ9hy-O0OmCFcWm9vrP9_D7wZhjOyQ8H9nn2dq8VbdMeArLSxRK1tkv9LOuEdrepOxgN9xL9k5i-yzQbXxJq32_0CGan3iBG=s642" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="487" data-original-width="642" height="243" src="https://blogger.googleusercontent.com/img/a/AVvXsEjLLKbLGWnTgyVGqo_tkwNu7NLbgZDd23_WhQtcjGYfqQeEoctjSsr-vKK-yQ55RinHxfPHGkA_kQcVBxtIPs85bG9tuJ9hy-O0OmCFcWm9vrP9_D7wZhjOyQ8H9nn2dq8VbdMeArLSxRK1tkv9LOuEdrepOxgN9xL9k5i-yzQbXxJq32_0CGan3iBG=s320" width="320" /></a></div><div><div style="text-align: center;">F<span style="text-align: center;">igure 1. Weekly
anhydrous ammonia prices.</span></div><p align="center" class="MsoNormal" style="text-align: center;"><o:p></o:p></p>
<p class="MsoNormal"><span style="font-family: "Times New Roman",serif; font-size: 12.0pt; line-height: 107%;">Farmers who historically have relied on synthetic
fertilizer, and even those who have used manure, but have limited experience
with spring application, should consider using some manure this spring. While
there is never a guarantee of what fertilizer prices will do in the future,
current prices are unprecedented. Until 2021, most years showed a lower average
price in the fall than in the spring. Even if your manure resources are limited
and applying some manure this spring means you won't be able to cover as much
ground next fall, it still represents an opportunity to save some money now since
fertilizer prices haven’t stabilized.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family: "Times New Roman",serif; font-size: 12.0pt; line-height: 107%;">ISU research evaluating the impact of swine manure
timing on the yield of corn has consistently shown moving manure application
closer to the growing season has a yield benefit. In 2021, with a dry fall and
spring nitrogen loss via leaching and denitrification was at a minimum. The yields
between fall and spring-applied manure were similar. We also compared spring
UAN fertilizer to spring manure application and found, on average, the spring
manure to corn (following soybean the previous growing season) out yielded the
spring UAN application by 13 bushels per acre.</span></p><p class="MsoNormal" style="text-align: left;"><a href="https://blogger.googleusercontent.com/img/a/AVvXsEgY6A9rm51QQ9axOJ0G0o7NUektdu6QP_mzSj2cSUiohlZdKes0P7it9K8K-AL2e0n87Ve6qqUF5KC9Yn8op5t_-zIXfv_uc14V-VjotzmSp8t2CvXpAcIOhkONAe6bz8BYTmgs3Emk8EmCBTsqm7t2ci5uW67zB7VqaSNbZk2JCJypsAyQEHsTW5Xg=s1640" imageanchor="1" style="margin-left: 1em; margin-right: 1em; text-align: center;"><img border="0" data-original-height="1254" data-original-width="1640" height="245" src="https://blogger.googleusercontent.com/img/a/AVvXsEgY6A9rm51QQ9axOJ0G0o7NUektdu6QP_mzSj2cSUiohlZdKes0P7it9K8K-AL2e0n87Ve6qqUF5KC9Yn8op5t_-zIXfv_uc14V-VjotzmSp8t2CvXpAcIOhkONAe6bz8BYTmgs3Emk8EmCBTsqm7t2ci5uW67zB7VqaSNbZk2JCJypsAyQEHsTW5Xg=s320" width="320" /></a></p></div><div><span style="text-align: center;">Figure 2. Average
corn yields for 2021 at the Nashua site.</span><p align="center" class="MsoNormal" style="text-align: center;"><o:p></o:p></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;"><o:p> </o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">Similarly,
this may be a good time to reexamine the nitrogen application rates you are
selecting. Manure management plans typically utilize the yield goal method to
set nitrogen application rate maximums, intended for environmental protection,
not to maximize profit. Rate selection tools, like Maximum Return to Nitrogen,
can be used to determine rates that will help you maximize your manure
fertility value and typically will help you stretch the manure across more
acres.<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;"><o:p> </o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">Farms
that have not historically used manure in the past may be more interested in
purchasing manure due to either inability to obtain other fertilizers or
because of the high prices. If you are working with someone new to using
manure, you can do a few things to help facilitate the exchange.<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;"><o:p> </o:p></span></p>
<ol start="1" style="margin-top: 0in;" type="1">
<li class="MsoNormal" style="color: #0e101a; line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; mso-list: l0 level1 lfo1; tab-stops: list .5in;"><span style="font-family: "Times New Roman",serif; font-size: 12.0pt;">Set a price
that works for both sides. Manure has value, and the value moves with the
price of other fertilizer sources. Can selling some manure now potentially
help you obtain acres for manure application in the future? If you are
selling manure, look for fields that can utilize the N, P, and K to
maximize value and price.<o:p></o:p></span></li>
<li class="MsoNormal" style="color: #0e101a; line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; mso-list: l0 level1 lfo1; tab-stops: list .5in;"><span style="font-family: "Times New Roman",serif; font-size: 12.0pt;">Know your
regulations. Suppose the manure is coming from a confinement animal
feeding operation. In that case, it needs to be applied by a certified
applicator. Unless it is sold under Chapter 200A, through an independent
manure broker, the field needs to be in a manure management plan (and have
appropriate soil tests and erosion assessment).<o:p></o:p></span></li>
<li class="MsoNormal" style="color: #0e101a; line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; mso-list: l0 level1 lfo1; tab-stops: list .5in;"><span style="font-family: "Times New Roman",serif; font-size: 12.0pt;">Share the
experiences you had in what helps you get the most value and best benefits
of your manure. Discuss improvements to soil health all the nitrogen won't
be available right away, and then state how the injection units will leave
the field or best practices you've found to make planting a success.<br style="mso-special-character: line-break;" />
<!--[if !supportLineBreakNewLine]--><br style="mso-special-character: line-break;" />
<!--[endif]--><o:p></o:p></span></li>
</ol>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a;">Higher
fertilizer prices make getting the most from your manure essential. Spring
application has consistently shown similar or improved yields. Moreover, with the
high fertilizer prices, getting manure nutrients to the right field at the
right time makes manure more valuable than ever.<o:p></o:p></span></p><div class="separator" style="clear: both; text-align: center;"><br /></div><br /><div class="separator" style="clear: both; text-align: center;"><br /></div><br /></div><div class="separator" style="clear: both; text-align: center;"><br /></div><br />Daniel Andersenhttp://www.blogger.com/profile/17296164974381593950noreply@blogger.com0tag:blogger.com,1999:blog-8695306981003495902.post-39556878338111691622022-01-25T11:25:00.004-06:002022-01-25T12:04:48.073-06:00Energy Embedded in Fertilizer and Impacts on Manure Carbon Management<p> </p><p class="MsoNormal"></p><p class="MsoNormal"><span style="font-size: 11.0pt; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin;">Last month we looked at how a few different
manure management decisions impacted carbon cycling in the manure. This time,
we are going to look at a different aspect of carbon, that being energy. While
we often think about the economics of fertilizer, with the greater emphasis on
climate change, greenhouse gases, and sustainable energy, it is important to look
at how different manure management decisions impact energy from a fertility
perspective.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size: 11.0pt; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin;"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size: 11.0pt; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin;">Obtaining fertilizers takes energy. In the
case of phosphorus and potassium, this energy is related to the difficulty of
mining and processing the fertilizers (for P<sub>2</sub>O<sub>5</sub>, this is
5600 Btu per pound, and for K<sub>2</sub>O, it is 4700 Btu per pound). For
nitrogen, it is the energy required to synthesize nitrogen from diatomic
nitrogen in the air (18,100 Btu per pound of N). Considering what this means in
terms of carbon emissions, it implies every pound of P<sub>2</sub>O<sub>5</sub>
is worth 0.65 lb CO<sub>2</sub>, a pound of K<sub>2</sub>O is worth 0.55 lb CO<sub>2</sub>,
and a pound of N is worth 2.1 lb CO<sub>2</sub>.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size: 11.0pt; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin;"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size: 11.0pt; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin;">Let’s look at what this implies for beef
finishing farms employing different manure management.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size: 11.0pt; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin;"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size: 11.0pt; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin;">Table 1: Summarizes the N, P<sub>2</sub>O<sub>5</sub>,
and K<sub>2</sub>O contents of typical manure from different systems and what
this means for differences for CO<sub>2</sub> use.</span></p>
<table border="0" cellpadding="0" cellspacing="0" class="MsoNormalTable" style="border-collapse: collapse; mso-padding-alt: 0in 5.4pt 0in 5.4pt; mso-yfti-tbllook: 1184; width: 423px;">
<tbody><tr style="height: 15.0pt; mso-yfti-firstrow: yes; mso-yfti-irow: 0;">
<td nowrap="" style="border-top: solid windowtext 1.0pt; border: none; height: 15.0pt; mso-border-top-alt: solid windowtext .5pt; padding: 0in 5.4pt 0in 5.4pt; width: 78.0pt;" valign="bottom" width="104">
<p align="center" class="MsoNormal" style="text-align: center;"><span style="color: black; mso-ascii-font-family: Calibri; mso-bidi-font-family: Calibri; mso-fareast-font-family: "Times New Roman"; mso-hansi-font-family: Calibri;"> <o:p></o:p></span></p>
</td>
<td nowrap="" style="border-top: solid windowtext 1.0pt; border: none; height: 15.0pt; mso-border-top-alt: solid windowtext .5pt; padding: 0in 5.4pt 0in 5.4pt; width: 30.35pt;" valign="bottom" width="40">
<p align="center" class="MsoNormal" style="text-align: center;"><span style="color: black; mso-ascii-font-family: Calibri; mso-bidi-font-family: Calibri; mso-fareast-font-family: "Times New Roman"; mso-hansi-font-family: Calibri;">N<o:p></o:p></span></p>
</td>
<td nowrap="" style="border-top: solid windowtext 1.0pt; border: none; height: 15.0pt; mso-border-top-alt: solid windowtext .5pt; padding: 0in 5.4pt 0in 5.4pt; width: 30.9pt;" valign="bottom" width="41">
<p align="center" class="MsoNormal" style="text-align: center;"><span style="color: black; mso-ascii-font-family: Calibri; mso-bidi-font-family: Calibri; mso-fareast-font-family: "Times New Roman"; mso-hansi-font-family: Calibri;">P<sub>2</sub>O<sub>5</sub><o:p></o:p></span></p>
</td>
<td nowrap="" style="border-top: solid windowtext 1.0pt; border: none; height: 15.0pt; mso-border-top-alt: solid windowtext .5pt; padding: 0in 5.4pt 0in 5.4pt; width: 30.35pt;" valign="bottom" width="40">
<p align="center" class="MsoNormal" style="text-align: center;"><span style="color: black; mso-ascii-font-family: Calibri; mso-bidi-font-family: Calibri; mso-fareast-font-family: "Times New Roman"; mso-hansi-font-family: Calibri;">K<sub>2</sub>O<o:p></o:p></span></p>
</td>
<td nowrap="" style="border-top: solid windowtext 1.0pt; border: none; height: 15.0pt; mso-border-top-alt: solid windowtext .5pt; padding: 0in 5.4pt 0in 5.4pt; width: 63.0pt;" valign="bottom" width="84">
<p align="center" class="MsoNormal" style="text-align: center;"><span style="color: black; mso-ascii-font-family: Calibri; mso-bidi-font-family: Calibri; mso-fareast-font-family: "Times New Roman"; mso-hansi-font-family: Calibri;">CO<sub>2</sub><o:p></o:p></span></p>
</td>
<td nowrap="" style="border-top: solid windowtext 1.0pt; border: none; height: 15.0pt; mso-border-top-alt: solid windowtext .5pt; padding: 0in 5.4pt 0in 5.4pt; width: 85.0pt;" valign="bottom" width="113">
<p align="center" class="MsoNormal" style="text-align: center;"><span style="color: black; mso-ascii-font-family: Calibri; mso-bidi-font-family: Calibri; mso-fareast-font-family: "Times New Roman"; mso-hansi-font-family: Calibri;">CO<sub>2</sub>/savings<o:p></o:p></span></p>
</td>
</tr>
<tr style="height: 15.75pt; mso-yfti-irow: 1;">
<td nowrap="" style="border-bottom: double windowtext 2.25pt; border: none; height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 78.0pt;" valign="bottom" width="104">
<p align="center" class="MsoNormal" style="text-align: center;"><span style="color: black; mso-ascii-font-family: Calibri; mso-bidi-font-family: Calibri; mso-fareast-font-family: "Times New Roman"; mso-hansi-font-family: Calibri;">Manure
System<o:p></o:p></span></p>
</td>
<td nowrap="" style="border-bottom: double windowtext 2.25pt; border: none; height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 30.35pt;" valign="bottom" width="40">
<p align="center" class="MsoNormal" style="text-align: center;"><span style="color: black; mso-ascii-font-family: Calibri; mso-bidi-font-family: Calibri; mso-fareast-font-family: "Times New Roman"; mso-hansi-font-family: Calibri;">lb<o:p></o:p></span></p>
</td>
<td nowrap="" style="border-bottom: double windowtext 2.25pt; border: none; height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 30.9pt;" valign="bottom" width="41">
<p align="center" class="MsoNormal" style="text-align: center;"><span style="color: black; mso-ascii-font-family: Calibri; mso-bidi-font-family: Calibri; mso-fareast-font-family: "Times New Roman"; mso-hansi-font-family: Calibri;">lb<o:p></o:p></span></p>
</td>
<td nowrap="" style="border-bottom: double windowtext 2.25pt; border: none; height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 30.35pt;" valign="bottom" width="40">
<p align="center" class="MsoNormal" style="text-align: center;"><span style="color: black; mso-ascii-font-family: Calibri; mso-bidi-font-family: Calibri; mso-fareast-font-family: "Times New Roman"; mso-hansi-font-family: Calibri;">lb<o:p></o:p></span></p>
</td>
<td nowrap="" style="border-bottom: double windowtext 2.25pt; border: none; height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 63.0pt;" valign="bottom" width="84">
<p align="center" class="MsoNormal" style="text-align: center;"><span style="color: black; mso-ascii-font-family: Calibri; mso-bidi-font-family: Calibri; mso-fareast-font-family: "Times New Roman"; mso-hansi-font-family: Calibri;">lb<o:p></o:p></span></p>
</td>
<td nowrap="" style="border-bottom: double windowtext 2.25pt; border: none; height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 85.0pt;" valign="bottom" width="113">
<p align="center" class="MsoNormal" style="text-align: center;"><span style="color: black; mso-ascii-font-family: Calibri; mso-bidi-font-family: Calibri; mso-fareast-font-family: "Times New Roman"; mso-hansi-font-family: Calibri;">Savings
per Head<o:p></o:p></span></p>
</td>
</tr>
<tr style="height: 15.75pt; mso-yfti-irow: 2;">
<td nowrap="" style="height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 78.0pt;" valign="bottom" width="104">
<p align="center" class="MsoNormal" style="text-align: center;"><span style="color: black; mso-ascii-font-family: Calibri; mso-bidi-font-family: Calibri; mso-fareast-font-family: "Times New Roman"; mso-hansi-font-family: Calibri;">Bedded
Pack<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 30.35pt;" valign="bottom" width="40">
<p align="center" class="MsoNormal" style="text-align: center;"><span style="color: black; mso-ascii-font-family: Calibri; mso-bidi-font-family: Calibri; mso-fareast-font-family: "Times New Roman"; mso-hansi-font-family: Calibri;">44.5<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 30.9pt;" valign="bottom" width="41">
<p align="center" class="MsoNormal" style="text-align: center;"><span style="color: black; mso-ascii-font-family: Calibri; mso-bidi-font-family: Calibri; mso-fareast-font-family: "Times New Roman"; mso-hansi-font-family: Calibri;">25.9<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 30.35pt;" valign="bottom" width="40">
<p align="center" class="MsoNormal" style="text-align: center;"><span style="color: black; mso-ascii-font-family: Calibri; mso-bidi-font-family: Calibri; mso-fareast-font-family: "Times New Roman"; mso-hansi-font-family: Calibri;">26.4<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 63.0pt;" valign="bottom" width="84">
<p align="center" class="MsoNormal" style="text-align: center;"><span style="color: black; mso-ascii-font-family: Calibri; mso-bidi-font-family: Calibri; mso-fareast-font-family: "Times New Roman"; mso-hansi-font-family: Calibri;">125<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 85.0pt;" valign="bottom" width="113">
<p align="center" class="MsoNormal" style="text-align: center;"><span style="color: black; mso-ascii-font-family: Calibri; mso-bidi-font-family: Calibri; mso-fareast-font-family: "Times New Roman"; mso-hansi-font-family: Calibri;">34<o:p></o:p></span></p>
</td>
</tr>
<tr style="height: 15.0pt; mso-yfti-irow: 3;">
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 78.0pt;" valign="bottom" width="104">
<p align="center" class="MsoNormal" style="text-align: center;"><span style="color: black; mso-ascii-font-family: Calibri; mso-bidi-font-family: Calibri; mso-fareast-font-family: "Times New Roman"; mso-hansi-font-family: Calibri;">Deep
Pit<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 30.35pt;" valign="bottom" width="40">
<p align="center" class="MsoNormal" style="text-align: center;"><span style="color: black; mso-ascii-font-family: Calibri; mso-bidi-font-family: Calibri; mso-fareast-font-family: "Times New Roman"; mso-hansi-font-family: Calibri;">42.7<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 30.9pt;" valign="bottom" width="41">
<p align="center" class="MsoNormal" style="text-align: center;"><span style="color: black; mso-ascii-font-family: Calibri; mso-bidi-font-family: Calibri; mso-fareast-font-family: "Times New Roman"; mso-hansi-font-family: Calibri;">26.8<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 30.35pt;" valign="bottom" width="40">
<p align="center" class="MsoNormal" style="text-align: center;"><span style="color: black; mso-ascii-font-family: Calibri; mso-bidi-font-family: Calibri; mso-fareast-font-family: "Times New Roman"; mso-hansi-font-family: Calibri;">37.3<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 63.0pt;" valign="bottom" width="84">
<p align="center" class="MsoNormal" style="text-align: center;"><span style="color: black; mso-ascii-font-family: Calibri; mso-bidi-font-family: Calibri; mso-fareast-font-family: "Times New Roman"; mso-hansi-font-family: Calibri;">128<o:p></o:p></span></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 85.0pt;" valign="bottom" width="113">
<p align="center" class="MsoNormal" style="text-align: center;"><span style="color: black; mso-ascii-font-family: Calibri; mso-bidi-font-family: Calibri; mso-fareast-font-family: "Times New Roman"; mso-hansi-font-family: Calibri;">37<o:p></o:p></span></p>
</td>
</tr>
<tr style="height: 15.0pt; mso-yfti-irow: 4; mso-yfti-lastrow: yes;">
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 15.0pt; mso-border-bottom-alt: solid windowtext .5pt; padding: 0in 5.4pt 0in 5.4pt; width: 78.0pt;" valign="bottom" width="104">
<p align="center" class="MsoNormal" style="text-align: center;"><span style="color: black; font-size: 11.0pt; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";">Open Lot<o:p></o:p></span></p>
</td>
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 15.0pt; mso-border-bottom-alt: solid windowtext .5pt; padding: 0in 5.4pt 0in 5.4pt; width: 30.35pt;" valign="bottom" width="40">
<p align="center" class="MsoNormal" style="text-align: center;"><span style="color: black; font-size: 11.0pt; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";">30.0<o:p></o:p></span></p>
</td>
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 15.0pt; mso-border-bottom-alt: solid windowtext .5pt; padding: 0in 5.4pt 0in 5.4pt; width: 30.9pt;" valign="bottom" width="41">
<p align="center" class="MsoNormal" style="text-align: center;"><span style="color: black; font-size: 11.0pt; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";">21.8<o:p></o:p></span></p>
</td>
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 15.0pt; mso-border-bottom-alt: solid windowtext .5pt; padding: 0in 5.4pt 0in 5.4pt; width: 30.35pt;" valign="bottom" width="40">
<p align="center" class="MsoNormal" style="text-align: center;"><span style="color: black; font-size: 11.0pt; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";">24.5<o:p></o:p></span></p>
</td>
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 15.0pt; mso-border-bottom-alt: solid windowtext .5pt; padding: 0in 5.4pt 0in 5.4pt; width: 63.0pt;" valign="bottom" width="84">
<p align="center" class="MsoNormal" style="text-align: center;"><span style="color: black; font-size: 11.0pt; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";">91<o:p></o:p></span></p>
</td>
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 15.0pt; mso-border-bottom-alt: solid windowtext .5pt; padding: 0in 5.4pt 0in 5.4pt; width: 85.0pt;" valign="bottom" width="113">
<p align="center" class="MsoNormal" style="text-align: center;"><span style="color: black; font-size: 11.0pt; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";">-<o:p></o:p></span></p>
</td>
</tr>
</tbody></table>
<p class="MsoNormal"><span style="font-size: 11.0pt; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin;"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size: 11.0pt; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin;">If we compare these options by holding onto
the manure’s fertilizer value, we save approximately 34-37 lb of CO<sub>2</sub>
per animal in extra nutrients that have been saved in manure. While this is
important and useful, one thing to keep in mind is that the carbon cycle itself
accounts for around 500-1000 lbs of CO<sub>2</sub> per pig space per year,
which is a fair amount more than the energy in the fertilizer value of the
manure. However, some of that CO<sub>2</sub> was recently recycled from the atmosphere
to plant material and then through the animal. In terms of energy not used to
make or obtain new fertilizer, carbon that has not been emitted represents a
true change in the carbon cycle.<o:p></o:p></span></p><br /><p></p>Daniel Andersenhttp://www.blogger.com/profile/17296164974381593950noreply@blogger.com0tag:blogger.com,1999:blog-8695306981003495902.post-4297713116454484512021-12-22T09:50:00.003-06:002021-12-22T09:50:47.129-06:00 Carbon Footprint on Swine Deep Pit Finishing Farms<p><span style="color: #0e101a; font-family: Calibri, sans-serif; font-size: 11pt;">Carbon cycles can be
as complex as we make them. In this case, I’m only going to focus on the manure
portion of the carbon cycle; that is to say, I’m not looking at how diet and
the crops are grown impact the carbon footprint, but only the manure management
choices we make.</span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a; font-family: "Calibri",sans-serif; font-size: 11.0pt; mso-ascii-theme-font: minor-latin; mso-bidi-theme-font: minor-latin; mso-hansi-theme-font: minor-latin;">In terms of carbon,
if we assume that the average weight of our pigs is 70 pounds and they excrete
manure at a rate of the ASABE standard (0.375 kg VS/animal-day), with
approximately 58% of the volatile solids being carbon, then every pig space
will generate 80 kg of carbon in the manure every year. All we can do is
control the form this carbon takes as we move it around.<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a; font-family: "Calibri",sans-serif; font-size: 11.0pt; mso-ascii-theme-font: minor-latin; mso-bidi-theme-font: minor-latin; mso-hansi-theme-font: minor-latin;"> </span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><em><span style="color: #0e101a; font-family: "Calibri",sans-serif; font-size: 11.0pt; mso-ascii-theme-font: minor-latin; mso-bidi-theme-font: minor-latin; mso-hansi-theme-font: minor-latin;">Daily Haul</span></em><span style="color: #0e101a; font-family: "Calibri",sans-serif; font-size: 11.0pt; mso-ascii-theme-font: minor-latin; mso-bidi-theme-font: minor-latin; mso-hansi-theme-font: minor-latin;"><o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a; font-family: "Calibri",sans-serif; font-size: 11.0pt; mso-ascii-theme-font: minor-latin; mso-bidi-theme-font: minor-latin; mso-hansi-theme-font: minor-latin;">Although this system
is minimally used in practice, it still gives us something to compare against.
One quick note, I won’t be accounting for the amount of energy used to hauling
the manure, only where that 80 kg of the carbon ends up. Most research suggests
about 13% of the carbon in manure is stabilized in soil, which amounts to 10
kg. The other 70kg of carbon is converted into carbon dioxide, so this system
generates about 257 kg CO<sub>2</sub> per pig.<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a; font-family: "Calibri",sans-serif; font-size: 11.0pt; mso-ascii-theme-font: minor-latin; mso-bidi-theme-font: minor-latin; mso-hansi-theme-font: minor-latin;"> </span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><em><span style="color: #0e101a; font-family: "Calibri",sans-serif; font-size: 11.0pt; mso-ascii-theme-font: minor-latin; mso-bidi-theme-font: minor-latin; mso-hansi-theme-font: minor-latin;">Deep Pit Manure
Storage</span></em><span style="color: #0e101a; font-family: "Calibri",sans-serif; font-size: 11.0pt; mso-ascii-theme-font: minor-latin; mso-bidi-theme-font: minor-latin; mso-hansi-theme-font: minor-latin;"><o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a; font-family: "Calibri",sans-serif; font-size: 11.0pt; mso-ascii-theme-font: minor-latin; mso-bidi-theme-font: minor-latin; mso-hansi-theme-font: minor-latin;">In a deep pit manure
storage, the average is approximately 12.2 kg CH<sub>4</sub> generated per
animal space per year. This is approximately 9.1 kg of carbon, but as methane,
it is 25 times stronger greenhouse gas than carbon dioxide, which works out to
305 kg CO<sub>2</sub> equivalents. While the manure is stored in the pit, CO<sub>2</sub>
is also generated and released; most manure-based biogas is approximately 60%
methane and 40% carbon dioxide. Assuming this ratio, we will generate another 8
kg of CO<sub>2</sub>, accounting for 2 kg of C.<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a; font-family: "Calibri",sans-serif; font-size: 11.0pt; mso-ascii-theme-font: minor-latin; mso-bidi-theme-font: minor-latin; mso-hansi-theme-font: minor-latin;"> </span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a; font-family: "Calibri",sans-serif; font-size: 11.0pt; mso-ascii-theme-font: minor-latin; mso-bidi-theme-font: minor-latin; mso-hansi-theme-font: minor-latin;">We started with 80
kg of carbon and have converted 17 kg into gasses before application, leaving
63 kg of carbon in the manure. Again, 13% of this carbon will be stabilized in
the soil, so approximately 8.2 kg, while the remaining 54.8 kg of carbon gets
converted into CO<sub>2</sub>, another 201 kg of CO<sub>2</sub>.<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a; font-family: "Calibri",sans-serif; font-size: 11.0pt; mso-ascii-theme-font: minor-latin; mso-bidi-theme-font: minor-latin; mso-hansi-theme-font: minor-latin;"> </span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a; font-family: "Calibri",sans-serif; font-size: 11.0pt; mso-ascii-theme-font: minor-latin; mso-bidi-theme-font: minor-latin; mso-hansi-theme-font: minor-latin;">Thus, in this
system, 508 kg of CO<sub>2</sub> equivalents are generated per pig space per
year. This is about double what we saw from the daily haul system because some
carbon is converted into methane, a potent greenhouse gas. This provides our
first insight into how to minimize our carbon footprint; reducing or
eliminating methane emissions is critical.<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a; font-family: "Calibri",sans-serif; font-size: 11.0pt; mso-ascii-theme-font: minor-latin; mso-bidi-theme-font: minor-latin; mso-hansi-theme-font: minor-latin;"> </span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><em><span style="color: #0e101a; font-family: "Calibri",sans-serif; font-size: 11.0pt; mso-ascii-theme-font: minor-latin; mso-bidi-theme-font: minor-latin; mso-hansi-theme-font: minor-latin;">Anaerobic Digestion
of Manure</span></em><span style="color: #0e101a; font-family: "Calibri",sans-serif; font-size: 11.0pt; mso-ascii-theme-font: minor-latin; mso-bidi-theme-font: minor-latin; mso-hansi-theme-font: minor-latin;"><o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a; font-family: "Calibri",sans-serif; font-size: 11.0pt; mso-ascii-theme-font: minor-latin; mso-bidi-theme-font: minor-latin; mso-hansi-theme-font: minor-latin;">In this case, we
will again, not be accounting for any energy that goes into moving manure for
land application or getting it into the digester, but I will account for energy
used in heating the anaerobic digester and for cleaning and compression of the
generated methane to put it on in a natural gas pipeline.<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a; font-family: "Calibri",sans-serif; font-size: 11.0pt; mso-ascii-theme-font: minor-latin; mso-bidi-theme-font: minor-latin; mso-hansi-theme-font: minor-latin;"> </span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a; font-family: "Calibri",sans-serif; font-size: 11.0pt; mso-ascii-theme-font: minor-latin; mso-bidi-theme-font: minor-latin; mso-hansi-theme-font: minor-latin;">Starting with our
previous assumptions, pigs are 70 pounds. They excrete manure at a rate of the
ASABE standard (0.375 kg VS/animal-day), with approximately 58% of the volatile
solids being carbon giving the 80 kg of carbon per pig space per year. But in
this case, we also need an estimated methane production potential, which I will
estimate as 0.4 m<sup>3</sup> CH<sub>4</sub>/kg VS.<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a; font-family: "Calibri",sans-serif; font-size: 11.0pt; mso-ascii-theme-font: minor-latin; mso-bidi-theme-font: minor-latin; mso-hansi-theme-font: minor-latin;"> </span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a; font-family: "Calibri",sans-serif; font-size: 11.0pt; mso-ascii-theme-font: minor-latin; mso-bidi-theme-font: minor-latin; mso-hansi-theme-font: minor-latin;">Anytime manure is
stored anaerobically, some of the organic matter will break down and release
methane and carbon dioxide. In an anaerobic digestion system, we want to
minimize this time so more of the methane is captured in the digester. I
assumed methane generated before manure collection and movement to a digester
as 0.05 m<sup>3</sup> CH<sub>4</sub>/kg VS. This amounts to 4 kg CH<sub>4</sub>
(3 kg of carbon, 75 kg CO<sub>2</sub> equivalents). Manure decomposition will
also generate 2.6 kg CO<sub>2</sub> (0.7 kg C).<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a; font-family: "Calibri",sans-serif; font-size: 11.0pt; mso-ascii-theme-font: minor-latin; mso-bidi-theme-font: minor-latin; mso-hansi-theme-font: minor-latin;"> </span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a; font-family: "Calibri",sans-serif; font-size: 11.0pt; mso-ascii-theme-font: minor-latin; mso-bidi-theme-font: minor-latin; mso-hansi-theme-font: minor-latin;">This leaves 0.35 m<sup>3</sup>
CH<sub>4</sub>/kg VS of potential; I assumed the digester would be 75%
efficient at converting potential into production. In the digester, we would
hope to generate 21 kg CH<sub>4</sub> (16 kg C), which will all be combusted
into CO<sub>2</sub> for power (58 kg CO<sub>2</sub>); however, this means we
don’t need to combust a fossil fuel for power, saving that CO<sub>2</sub> from
being emitted, making this a negative emission of 58 kg CO<sub>2</sub>. During
digestion, we will generate 14 kg CO<sub>2</sub> (4 kg C).<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a; font-family: "Calibri",sans-serif; font-size: 11.0pt; mso-ascii-theme-font: minor-latin; mso-bidi-theme-font: minor-latin; mso-hansi-theme-font: minor-latin;"> </span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a; font-family: "Calibri",sans-serif; font-size: 11.0pt; mso-ascii-theme-font: minor-latin; mso-bidi-theme-font: minor-latin; mso-hansi-theme-font: minor-latin;">The effluent from
the digester needs to be stored, and as it is stored, more methane and CO<sub>2</sub>
will be emitted. I assume that 10% of the remaining potential will be converted
to methane. This is 0.7 kg CH<sub>4</sub> (0.5 kg C, 2 kg CO<sub>2</sub>
equivalents) and 0.45 kg CO<sub>2</sub> (0.1 kg C). <o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a; font-family: "Calibri",sans-serif; font-size: 11.0pt; mso-ascii-theme-font: minor-latin; mso-bidi-theme-font: minor-latin; mso-hansi-theme-font: minor-latin;"> </span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a; font-family: "Calibri",sans-serif; font-size: 11.0pt; mso-ascii-theme-font: minor-latin; mso-bidi-theme-font: minor-latin; mso-hansi-theme-font: minor-latin;">These emissions leave
us with 55 kg C in manure. Again, assuming 13% will stabilize in the soil (7 kg
C) and the rest will become CO<sub>2</sub> (48 kg C, 176 kg CO<sub>2</sub>).<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a; font-family: "Calibri",sans-serif; font-size: 11.0pt; mso-ascii-theme-font: minor-latin; mso-bidi-theme-font: minor-latin; mso-hansi-theme-font: minor-latin;"> </span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a; font-family: "Calibri",sans-serif; font-size: 11.0pt; mso-ascii-theme-font: minor-latin; mso-bidi-theme-font: minor-latin; mso-hansi-theme-font: minor-latin;">Doing some math, we
are at 212 kg CO<sub>2</sub> per pig space per year. I still need the energy to
heat the digester and compress biogas. How much heat is needed is dependent on
location, digester design, insulation value, and operation scale. As a best
guess, I estimate this as 0.144 MMBtu per pig, with each MMBtu time 53 kg CO<sub>2</sub>/MMbtu
giving 7.6 kg CO<sub>2</sub>. Cleaning and compressing the biogas from a pig
space would take approximately 30 kWh, with every kWh generating about 0.38 kg
of CO<sub>2</sub>. Compression and cleaning of the biogas take 11.6 kg CO<sub>2</sub>
gives a carbon balance of 231 kg CO<sub>2 </sub>equivalents per pig space per
year.<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a; font-family: "Calibri",sans-serif; font-size: 11.0pt; mso-ascii-theme-font: minor-latin; mso-bidi-theme-font: minor-latin; mso-hansi-theme-font: minor-latin;"> </span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><i><span style="color: #0e101a; font-family: "Calibri",sans-serif; font-size: 11.0pt; mso-ascii-theme-font: minor-latin; mso-bidi-theme-font: minor-latin; mso-hansi-theme-font: minor-latin;">Implications:<o:p></o:p></span></i></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span style="color: #0e101a; font-family: "Calibri",sans-serif; font-size: 11.0pt; mso-ascii-theme-font: minor-latin; mso-bidi-theme-font: minor-latin; mso-hansi-theme-font: minor-latin;">What does this tell
us? If we can find a way to encourage the adoption of anaerobic digestion
systems, we can save around 277 kg CO<sub>2</sub> equivalents per pig space per
year, a reduction of 55% compared to our baseline, and even slightly lower than
the daily haul system. More importantly, we get that without wasting as much
fertilizer value the manure would offer as daily haul systems will typically
result in large amounts of nitrogen loss (next Scoop, we’ll look at energy in
fertilizers and what that means for different manure systems).<o:p></o:p></span></p>Daniel Andersenhttp://www.blogger.com/profile/17296164974381593950noreply@blogger.com0tag:blogger.com,1999:blog-8695306981003495902.post-4707285906267687532021-10-13T10:56:00.000-05:002021-10-13T10:56:07.108-05:00Impact of Variability of Cattle Manure Application on Soil Nutrients and Crop Yield<p> <span style="color: #0e101a;">A study from 2011 and
2012 up in Saskatchewan looked at how the rate and uniformity of solid cattle
manure application impacted crop yield under two fertilizer practices, manure
application only and manure with supplemental urea fertilizer. This study is
unique because it focuses on solid manure application uniformity with and
without supplemental fertilizer. It used three different manure spreaders to
give different manure application uniformities.</span></p>
<p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><span style="color: #0e101a; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";"> </span></p>
<p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><span style="color: #0e101a; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";">Manure rates tested were
0, 9, and 27 tons per acre, respectively, with three different coefficients of
variation of manure application achieved (10, 50, and 110%). The low
application rate supplied approximately 150 lb total N/acre, while the high
rate supplied around 450 lb total N/acre. No statement on the fraction
estimated to be plant available was provided, but it is fair to assume approximately
50%. On half of the plots, an additional 71 lb N/acre was applied using urea.
They repeated two years growing oats in year one and barely in year two. Each
year's yield was scaled to the percent of max for that year and then averaged.<o:p></o:p></span></p><p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj5lfst__q8Q2iBrsU9cylNP71ioymFQvNmhi81spNZFU2t2VIZJhMnBJPa-bvyze-bpnwzyiAm3mKZoYTxLeEdS82Jhi9UNag23bPuC8j4e7h-lsA2QmV_ZfrI1fDuCZ-MOO-oexadVFc/s732/graph.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="449" data-original-width="732" height="196" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj5lfst__q8Q2iBrsU9cylNP71ioymFQvNmhi81spNZFU2t2VIZJhMnBJPa-bvyze-bpnwzyiAm3mKZoYTxLeEdS82Jhi9UNag23bPuC8j4e7h-lsA2QmV_ZfrI1fDuCZ-MOO-oexadVFc/s320/graph.png" width="320" /></a></div><br /><span style="color: #0e101a; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";"><br /></span><p></p><p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><span style="color: #0e101a; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";">Figure 1. Illustration
of how solid cattle manure application rate (tons/acre) and uniformity
(coefficient of variation) impacted crop yield (for oats and barley) as a
function of maximum yield achieved.<o:p></o:p></span></p><p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><span style="color: #0e101a; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";"> </span></p><p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><b><span style="color: #0e101a; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";">Important notes and
take-homes:<o:p></o:p></span></b></p><p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><span style="color: #0e101a; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";">In all cases, the use of
urea increased crop production, causing a significant increase (p = 0.0005) in
yield. Solid manure can provide sufficient nitrogen to support crop nitrogen
need on an annual basis. Still, in many cases, the higher carbon content of the
manure causes early-season nitrogen tie-up, so while overall availability may
be sufficient, there could still be periods of inadequate nitrogen supply.<o:p></o:p></span></p><p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><span style="color: #0e101a; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";"> </span><span style="color: #0e101a;">There were no
statistical differences among treatments where urea was applied. These
treatments all had sufficient nutrients to maximize yield. Urea on its own was
sufficient to provide the nitrogen the crops needed.</span></p><p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><span style="color: #0e101a; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";"> </span><span style="color: #0e101a;">There was no statistical
difference between manure application rates (p = 0.22). While we think more is
often better, adding more manure didn't improve yield, presumably because while
overall nitrogen supply was increased, a greater tie-up of nitrogen occurred
with the greater manure application rates, causing a more seasonal deficiency.</span></p><p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><span style="color: #0e101a; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman";"> </span><span style="color: #0e101a;">While no impact of
application variability was seen on the urea applied plots, in the manure-only
plots, application variability of 50% had more significant yields than 10%
statistically but was no different than 110%. Generally, the data suggest
improved uniformity increased yield at the higher application rate, where
manure had to supply fertility.</span></p>Daniel Andersenhttp://www.blogger.com/profile/17296164974381593950noreply@blogger.com0tag:blogger.com,1999:blog-8695306981003495902.post-55742244808595848202021-06-09T12:55:00.004-05:002021-06-09T12:55:35.499-05:00How does uncertainty impact the manure nitrogen application rate you select?<p> <span style="color: #0e101a; font-family: "Times New Roman", serif; font-size: 12pt;">Selecting an
appropriate nitrogen fertilizer rate is critical for optimizing profit from
cornfields. Applying too little N reduces profit by reducing grain yield; too
much N and you don’t get a return on the nitrogen you bought and can cause
damage to the environment. In Iowa, most manure management plans are filled out
using the yield goal method, with current university guidelines suggesting the
use of the maximum return to nitrogen approach. If you are a long-time reader
of this blog, you’ve probably seen both of these discussed before, so don’t
worry, that isn’t the topic today. Instead, I’m focusing on uncertainties in
the application and what that means for how we make decisions.</span></p>
<p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><span style="color: #0e101a; font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";">A lot of uncertainties
exist when using manure as a fertilizer. Some examples include:<o:p></o:p></span></p>
<p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><span style="color: #0e101a; font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";"> </span><span style="color: #0e101a; font-family: "Times New Roman", serif; font-size: 12pt;">· Nitrogen need of the
crop (every growing season is a bit different)</span></p>
<p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><span style="color: #0e101a; font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";">· Spatial variation in
nitrogen need to support crop production (because all soils aren’t the same)<o:p></o:p></span></p>
<p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><span style="color: #0e101a; font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";">· Nutrient content of
the manure<o:p></o:p></span></p>
<p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><span style="color: #0e101a; font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";">· Nutrient variation
from start to finish of manure application<o:p></o:p></span></p>
<p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><span style="color: #0e101a; font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";">· Application Rate
Control and Variation in Application Rate<o:p></o:p></span></p>
<p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><span style="color: #0e101a; font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";">· Availability of the
manure nitrogen to the crop<o:p></o:p></span></p>
<p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><span style="color: #0e101a; font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";">· Amount of nitrogen
lost to volatilization<o:p></o:p></span></p>
<p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><span style="color: #0e101a; font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";">· Non-uniformity in
application rate<o:p></o:p></span></p>
<p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><span style="color: #0e101a; font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";"><o:p> </o:p></span><span style="color: #0e101a; font-family: "Times New Roman", serif; font-size: 12pt;">For now, I want to
look at the manure application parts of this uncertainty and assume we know the
crop response to nitrogen perfectly. How do all the variations and uncertainty
impact the nitrogen application rate we should select? To answer this question,
I first parameterized the yield response curve from the maximum return to
nitrogen. The price of corn was set at $5.65 a bushel and nitrogen price at
$0.40 a pound, which in a corn-soybean rotation gave an optimal nitrogen rate
of 150 lb N/acre.</span></p>
<p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><span style="color: #0e101a; font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";"><o:p> </o:p></span><span style="color: #0e101a; font-family: "Times New Roman", serif; font-size: 12pt;">The manure nitrogen
content was set at 40 lbs N/1000 gallon, nitrogen availability at 95%, the
nitrogen volatilization coefficient at 98%, and the desired application rate of
3706 gallons/acre calculated. A Monte Carlo simulation was then performed. For
each variable that added uncertainty (manure N/content, Application rate,
Volatilization coefficient, Nitrogen availability, and the knife-to-knife
coefficient of variation), a normal distribution was constructed using the average
value listed above and standard deviations of 2.75 lb N/1000 gallons, 250
gallons/acre, 0.01 % volatilization, and 0.05 % availability, respectively.
Knife-to-knife variation varied between 0 and 100% were evaluated. I then
performed 3500 simulations drawing randomly from the distributions I created to
determine the nitrogen application rate for each knife (for distributions with
natural limits, such as volatilization coefficient, no values over 100% were
allowed).</span></p>
<p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><span style="color: #0e101a; font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";"><o:p> </o:p></span><span style="color: #0e101a; font-family: "Times New Roman", serif; font-size: 12pt;">A lost value from
application variability and uncertainty was calculated. If the actual amount of
available N applied was greater than the MRTN rate of 150 lb N/acre, the value
was set at the differences between the amount of N used minus 150 lb N/acre
times a nitrogen price of $0.40 a pounds. If the nitrogen application rate was
less than the MRTN rate, the value was set at the difference between corn yield
at MRTN and the projected corn yield at the N rate applied times a corn price
of $5.65 a bushel. The average loss in profit for all 400 knife simulations for
each of the 3500 simulations was calculated, and then the average and standard
deviation of the 3500 simulations were calculated.</span></p>
<p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><span style="color: #0e101a; font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";">A maximum return curve
was calculated by taking the profit that would have been generated with perfect
information (200 bu/acre x $5.65/bu – 150 lb N/acre x $0.40/lb N) minus the
profit lost from uncertainty and application variability using the procedure
listed above. Here we see an interesting trend – the uncertainty of ammonia
volatilization and nitrogen availability and the variation in volumetric
application rate and manure nitrogen content during the application, make it
advisable to apply six pounds more available nitrogen per acre than if we
didn’t have these variations. This occurs as the economics of nitrogen
application is non-symmetrical, with the cost of being a pound short greater
than being a pound heavy. Suppose we factor in any knife-to-knife application
variability. The story gets more interesting, with the ideal application rate first
increasing (until we reach a knife-to-knife application variability of about
40%, where the ideal rate is 167 pounds of N/acre, or 17 pounds/acre higher
than the known nitrogen response curve we put in. Ideal nitrogen rate then
decreasing to 137 lb available N/acre.<o:p></o:p></span></p>
<p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><span style="font-family: "Times New Roman",serif; font-size: 12.0pt;"><o:p> </o:p></span></p>
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjcw-zIjMuKVlQEqrhZ7jsg7tSNxgOzbBqsSqlcNT5NbagqUARBJqz-IYVkkHoKN_l5PKbgLmK_qkvbldH_vcDbL8UvJ4wI8-820gMOT3P7Y_bfUxGJLtFVh-BCbr0QvyGKVWWm06JWZqs/s601/Figure1.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="361" data-original-width="601" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjcw-zIjMuKVlQEqrhZ7jsg7tSNxgOzbBqsSqlcNT5NbagqUARBJqz-IYVkkHoKN_l5PKbgLmK_qkvbldH_vcDbL8UvJ4wI8-820gMOT3P7Y_bfUxGJLtFVh-BCbr0QvyGKVWWm06JWZqs/s320/Figure1.jpg" width="320" /></a></div><br /><div class="separator" style="clear: both; text-align: center;"><b style="text-align: left;"><span style="color: #0e101a; font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";">Figure 1.</span></b><span style="color: #0e101a; font-family: "Times New Roman", serif; font-size: 12pt; text-align: left;"> Impact of knife-to-knife variability of
the effects of the maximum return to nitrogen for spring-applied swine manure
to corn in a corn-soybean rotation. The ideal rate varies with our machinery
variation.</span></div>
<p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><span style="color: #0e101a; font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";"><o:p> </o:p></span></p>
<p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><span style="color: #0e101a; font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";">But what about a fall
application? As the MRTN curve is based on spring nitrogen applications, I
added a term to the model to account for N-loss from fall to spring. For fall
applications, I assumed an average of 15 lbs N/acre with a standard deviation of
15 lb N/acre and performed the same Monte Carlo simulation as above (but with
the available N corrected for estimated nitrogen loss.<o:p></o:p></span></p>
<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiGFFn9IrBA8uNF6rIYYZ0GN3wehYZlE1FxO6SrKEjbB7DNklMn1weYRsTCfRrK3jdqtM9ZD7ksF5fvFrFEQZ5xjygv0hyphenhyphenkzflLIx2D5McaJbFGVlYCyCdNdNl8jrcn1tW__tjuSMoV2j8/s480/Figure2.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="288" data-original-width="480" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiGFFn9IrBA8uNF6rIYYZ0GN3wehYZlE1FxO6SrKEjbB7DNklMn1weYRsTCfRrK3jdqtM9ZD7ksF5fvFrFEQZ5xjygv0hyphenhyphenkzflLIx2D5McaJbFGVlYCyCdNdNl8jrcn1tW__tjuSMoV2j8/s320/Figure2.png" width="320" /></a></div><p align="center" class="MsoNormal" style="text-align: center;"><strong><span style="color: #0e101a; font-family: "Calibri",sans-serif; mso-ascii-theme-font: minor-latin; mso-bidi-font-family: "Times New Roman"; mso-bidi-theme-font: minor-bidi; mso-hansi-theme-font: minor-latin;">Figure 2.</span></strong> Impact
of knife-to-knife variability on the impact of the maximum return to nitrogen
for a fall and spring-applied swine manure to corn in a corn-soybean rotation
and continuous corn rotations. The ideal rate varies with our machinery
variation.</p>
<p class="MsoNormal"><span style="font-family: "Times New Roman",serif; font-size: 12.0pt; line-height: 107%;">Almost all the curves looked the same. For example,
the Maximum Return to Nitrogen in a continuous corn rotation was approximately
50 pounds higher in the continuous corn rotation than in the corn-soybean
rotation, whether the manure was applied in the fall or the spring. The
difference was impacted slightly by the knife-to-knife variability of the
application equipment, but only slightly. Similarly, while the nitrogen loss
from fall application was set at 15 lb N/acre, the fall application rates were
on average 22 lb N/acre higher to hit the optimal rate.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family: "Times New Roman",serif; font-size: 12.0pt; line-height: 107%;">So overall, where does this leave us. There is
uncertainty and variability in every decision we make. The more confident we
are about our equipment and manure, the closer our rate should be to the “true”
MRTN. However, from an economic perspective, if there is uncertainty or
variability in what we are doing, the right rate for us sneaks upward just
slightly. This insurance N helps us in years we’d otherwise be short. And this
is why we still talk about the 4Rs of right rate, right place, right timing,
and the right type of fertilizer.<o:p></o:p></span></p>Daniel Andersenhttp://www.blogger.com/profile/17296164974381593950noreply@blogger.com0tag:blogger.com,1999:blog-8695306981003495902.post-6173518893286224352021-03-19T15:23:00.006-05:002021-03-24T18:35:39.680-05:00Manure Scoop: The Value of Real Time Nutrient Sensing<p> </p><p style="margin-bottom: .0001pt; margin: 0in;"><span face=""Calibri",sans-serif" style="color: #0e101a; font-size: 11pt; mso-ascii-theme-font: minor-latin; mso-bidi-font-family: "Times New Roman"; mso-hansi-theme-font: minor-latin;">A few years
ago, I became interested in the value of manure sampling and how obtaining good
information helped us make better nutrient management decisions. I tried to use
the theory of value of data to determine how much a manure sample was worth.
Read a summary </span><a href="http://themanurescoop.blogspot.com/2014/10/economic-value-of-manure-sampling-and.html"><span face=""Calibri",sans-serif" style="font-size: 11pt; mso-ascii-theme-font: minor-latin; mso-bidi-font-family: "Times New Roman"; mso-hansi-theme-font: minor-latin;">here</span></a><span face=""Calibri",sans-serif" style="font-size: 11pt; mso-ascii-theme-font: minor-latin; mso-bidi-font-family: "Times New Roman"; mso-hansi-theme-font: minor-latin;">.<span style="color: #0e101a;"> <o:p></o:p></span></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span face=""Calibri",sans-serif" style="color: #0e101a; font-size: 11pt; mso-ascii-theme-font: minor-latin; mso-bidi-font-family: "Times New Roman"; mso-hansi-theme-font: minor-latin;"><o:p> </o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span face=""Calibri",sans-serif" style="color: #0e101a; font-size: 11pt; mso-ascii-theme-font: minor-latin; mso-bidi-font-family: "Times New Roman"; mso-hansi-theme-font: minor-latin;">Many factors cause
variations in manure's average nutrient concentration: diet, housing type,
manure storage type, environmental conditions, management techniques, and
treatment practices. Just as critically, our ability to agitate and create a
uniform, homogeneous mixture is often limited by our ability to stir manure
storages.<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span face=""Calibri",sans-serif" style="color: #0e101a; font-size: 11pt; mso-ascii-theme-font: minor-latin; mso-bidi-font-family: "Times New Roman"; mso-hansi-theme-font: minor-latin;"><o:p> </o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span face=""Calibri",sans-serif" style="color: #0e101a; font-size: 11pt; mso-ascii-theme-font: minor-latin; mso-bidi-font-family: "Times New Roman"; mso-hansi-theme-font: minor-latin;">A repeated
sampling at five manure storages was used to assess the average, standard
deviation, and coefficient of variability. The data were summarized as averages
across the sampling data set to determine the variability in manure
concentrations from each manure application event. Average manure nutrient
concentrations were 28, 16, and 21 pounds of N, P, and K, respectively, per 1,000
gallons with standard deviations of 4, 7, and 3.<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span face=""Calibri",sans-serif" style="color: #0e101a; font-size: 11pt; mso-ascii-theme-font: minor-latin; mso-bidi-font-family: "Times New Roman"; mso-hansi-theme-font: minor-latin;"><o:p> </o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span face=""Calibri",sans-serif" style="color: #0e101a; font-size: 11pt; mso-ascii-theme-font: minor-latin; mso-bidi-font-family: "Times New Roman"; mso-hansi-theme-font: minor-latin;">In
determining the manure test's value, it is essential to understand how a farmer
can use the information gained from the test results, i.e., how having this
information alters the farmer's nutrient management and affects the farm
profit. This is a complex topic, as almost limitless possibilities exist. This
evaluation assumed the manure application method would be either injection or
immediate incorporation to maximize N utilization. Additionally, we assumed
best management practices for manure application timing were followed. As a
result, the yield response to available N (defined here as the sum of ammonia N
and organic N expected to mineralize in the first growing season) would be the
same as the yield response to mineral N fertilizer. Finally, we limited crop
rotation choices to continuous corn and corn-soybean rotations, as these
represent the dominant rotations in the upper Midwestern U.S.<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span face=""Calibri",sans-serif" style="color: #0e101a; font-size: 11pt; mso-ascii-theme-font: minor-latin; mso-bidi-font-family: "Times New Roman"; mso-hansi-theme-font: minor-latin;"><o:p> </o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span face=""Calibri",sans-serif" style="color: #0e101a; font-size: 11pt; mso-ascii-theme-font: minor-latin; mso-bidi-font-family: "Times New Roman"; mso-hansi-theme-font: minor-latin;">Our
methodology was to estimate the profit that would have been made if the manure
was assumed to have a "typical" nutrient composition and then to
compare this to the profit generated if the actual nutrient composition was
known. To make this evaluation, an economic model was developed as an Excel
spreadsheet. The model compared the costs and revenue of corn production. Corn
yield was calculated as the product of maximum yield and the estimated percent
yield that was achieved.<o:p></o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span face=""Calibri",sans-serif" style="color: #0e101a; font-size: 11pt; mso-ascii-theme-font: minor-latin; mso-bidi-font-family: "Times New Roman"; mso-hansi-theme-font: minor-latin;"><o:p> </o:p></span></p>
<p style="margin-bottom: .0001pt; margin: 0in;"><span face=""Calibri",sans-serif" style="color: #0e101a; font-size: 11pt; mso-ascii-theme-font: minor-latin; mso-bidi-font-family: "Times New Roman"; mso-hansi-theme-font: minor-latin;">For a
corn-soybean rotation where the manure is going to corn, this means that the
real-time nutrient correction for manure would be worth approximately $3.13 per
acre. However, in a continuous corn rotation, which is more sensitive to
nitrogen application in terms of crop response, it would be worth around $4.29 per acre. However, understanding just how big this variability is from
load-to-load or pass-to-pass is critical for putting value to this technology.<o:p></o:p></span></p>Daniel Andersenhttp://www.blogger.com/profile/17296164974381593950noreply@blogger.com0tag:blogger.com,1999:blog-8695306981003495902.post-69156088849615744702021-01-20T08:09:00.003-06:002021-01-20T08:09:46.903-06:00Manure Nitrogen Availability from Manures and N Application Recommendations Around the Midwest<p style="text-align: left;"> </p><p class="MsoNormal" style="line-height: normal; margin-bottom: 0.0001pt; text-align: left;"><span style="color: #0e101a; font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";">How much nutrient is
there? While it seems a simple question, with manures where the only thing
consistent about them is inconsistency, the answer isn't always easy. The place
I like to start is what does 'availability' mean.<o:p></o:p></span></p>
<p class="MsoNormal" style="line-height: normal; margin-bottom: 0.0001pt; text-align: left;"><span style="color: #0e101a; font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";"><o:p> </o:p></span><span style="color: #0e101a; font-family: "Times New Roman", serif; font-size: 12pt;">I define </span><b style="color: #0e101a; font-family: "Times New Roman", serif; font-size: 12pt;">availability</b><span style="color: #0e101a; font-family: "Times New Roman", serif; font-size: 12pt;"> as
nitrogen present in a form able to be used. When talking about manures, we
typically mean that this percent of the nutrient will cycle through a form that
plants can use.</span></p>
<p class="MsoNormal" style="line-height: normal; margin-bottom: 0.0001pt; text-align: left;"><span style="color: #0e101a; font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";">I'll use the
term <b>supply</b> to specify how much is added; less the fractions
are lost to volatilization, leaching, denitrification.<o:p></o:p></span></p>
<p class="MsoNormal" style="line-height: normal; margin-bottom: 0.0001pt; text-align: left;"><span style="color: #0e101a; font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";"><o:p> </o:p></span><span style="color: #0e101a; font-family: "Times New Roman", serif; font-size: 12pt;">Within the state of
Iowa, our go-to document on the subject of nutrient availability is "Using
Manure Nutrients for Crop Production," specifically table 1. A second
correction is made for ammonia volatilization losses based on the type of
manure (as this impacts the amount of nitrogen that is in the ammonium at the
time of application) and the application method (as this influences how long
the manure it's on the surface and is exposed for potential losses.</span></p><p class="MsoNormal" style="line-height: normal; margin-bottom: 0.0001pt; text-align: left;"></p><p align="center" class="MsoNormal" style="text-align: center;"><b>Table 1. Iowa Suggested Manure Nutrient Availability.<o:p></o:p></b></p><div align="center">
<table border="0" cellpadding="0" cellspacing="0" class="MsoNormalTable" style="border-collapse: collapse; mso-padding-alt: 0in 5.4pt 0in 5.4pt; mso-yfti-tbllook: 1184; width: 384px;">
<tbody><tr style="height: 15.0pt; mso-yfti-firstrow: yes; mso-yfti-irow: 0;">
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 15.0pt; mso-border-bottom-alt: solid windowtext .5pt; padding: 0in 5.4pt 0in 5.4pt; width: 133.0pt;" valign="bottom" width="177">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;"><b>Manure Source<o:p></o:p></b></p>
</td>
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 15.0pt; mso-border-bottom-alt: solid windowtext .5pt; padding: 0in 5.4pt 0in 5.4pt; width: 51.5pt;" valign="bottom" width="69">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;"><b>1st Year<o:p></o:p></b></p>
</td>
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 15.0pt; mso-border-bottom-alt: solid windowtext .5pt; padding: 0in 5.4pt 0in 5.4pt; width: .75in;" valign="bottom" width="72">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;"><b>2nd Year<o:p></o:p></b></p>
</td>
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 15.0pt; mso-border-bottom-alt: solid windowtext .5pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" valign="bottom" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;"><b>3rd Year<o:p></o:p></b></p>
</td>
</tr>
<tr style="height: 15.0pt; mso-yfti-irow: 1;">
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 133.0pt;" valign="bottom" width="177">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">Beef Cattle (solid or liquid)<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 51.5pt;" valign="bottom" width="69">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">30-50<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: .75in;" valign="bottom" width="72">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">10<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" valign="bottom" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">5<o:p></o:p></p>
</td>
</tr>
<tr style="height: 15.0pt; mso-yfti-irow: 2;">
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 133.0pt;" valign="bottom" width="177">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">Dairy (solid or liquid)<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 51.5pt;" valign="bottom" width="69">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">30-50<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: .75in;" valign="bottom" width="72">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">10<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" valign="bottom" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">5<o:p></o:p></p>
</td>
</tr>
<tr style="height: 15.0pt; mso-yfti-irow: 3;">
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 133.0pt;" valign="bottom" width="177">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">Liquid swine<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 51.5pt;" valign="bottom" width="69">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">90-100<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: .75in;" valign="bottom" width="72">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">0-10<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" valign="bottom" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">0<o:p></o:p></p>
</td>
</tr>
<tr style="height: 15.0pt; mso-yfti-irow: 4; mso-yfti-lastrow: yes;">
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 15.0pt; mso-border-bottom-alt: solid windowtext .5pt; padding: 0in 5.4pt 0in 5.4pt; width: 133.0pt;" valign="bottom" width="177">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">Poultry<o:p></o:p></p>
</td>
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 15.0pt; mso-border-bottom-alt: solid windowtext .5pt; padding: 0in 5.4pt 0in 5.4pt; width: 51.5pt;" valign="bottom" width="69">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">50-60<o:p></o:p></p>
</td>
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 15.0pt; mso-border-bottom-alt: solid windowtext .5pt; padding: 0in 5.4pt 0in 5.4pt; width: .75in;" valign="bottom" width="72">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">0-10<o:p></o:p></p>
</td>
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 15.0pt; mso-border-bottom-alt: solid windowtext .5pt; padding: 0in 5.4pt 0in 5.4pt; width: 49.5pt;" valign="bottom" width="66">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">0<o:p></o:p></p>
</td>
</tr>
</tbody></table>
</div><p align="center" class="MsoNormal" style="text-align: center;"><b>Table 2. Iowa Suggested Manure Nitrogen Volatilization Correction Factors.</b></p><p align="center" class="MsoNormal" style="text-align: center;">
</p><table border="0" cellpadding="0" cellspacing="0" class="MsoNormalTable" style="border-collapse: collapse; mso-padding-alt: 0in 5.4pt 0in 5.4pt; mso-yfti-tbllook: 1184; width: 558px;">
<tbody><tr style="height: 15.75pt; mso-yfti-firstrow: yes; mso-yfti-irow: 0;">
<td nowrap="" style="border-bottom: double windowtext 2.25pt; border-left: none; border-right: none; border-top: solid windowtext 1.0pt; height: 15.75pt; mso-border-bottom-alt: double windowtext 2.25pt; mso-border-top-alt: solid windowtext .5pt; padding: 0in 5.4pt 0in 5.4pt; width: 116.0pt;" valign="bottom" width="155">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;"><b>Application Method<o:p></o:p></b></p>
</td>
<td nowrap="" style="border-bottom: double windowtext 2.25pt; border-left: none; border-right: none; border-top: solid windowtext 1.0pt; height: 15.75pt; mso-border-bottom-alt: double windowtext 2.25pt; mso-border-top-alt: solid windowtext .5pt; padding: 0in 5.4pt 0in 5.4pt; width: 124.0pt;" valign="bottom" width="165">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;"><b>Incorporation<o:p></o:p></b></p>
</td>
<td nowrap="" style="border-bottom: double windowtext 2.25pt; border-left: none; border-right: none; border-top: solid windowtext 1.0pt; height: 15.75pt; mso-border-bottom-alt: double windowtext 2.25pt; mso-border-top-alt: solid windowtext .5pt; padding: 0in 5.4pt 0in 5.4pt; width: 178.5pt;" valign="bottom" width="238">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;"><b>Volatilization Correction Factor<o:p></o:p></b></p>
</td>
</tr>
<tr style="height: 15.75pt; mso-yfti-irow: 1;">
<td nowrap="" style="height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 116.0pt;" valign="bottom" width="155">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">Direct Injection<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 124.0pt;" valign="bottom" width="165">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">-<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.75pt; padding: 0in 5.4pt 0in 5.4pt; width: 178.5pt;" valign="bottom" width="238">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">0.98-1.00<o:p></o:p></p>
</td>
</tr>
<tr style="height: 15.0pt; mso-yfti-irow: 2;">
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 116.0pt;" valign="bottom" width="155">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">Broadcast (liquid/solid)<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 124.0pt;" valign="bottom" width="165">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">Immediate Incorporation<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 178.5pt;" valign="bottom" width="238">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">0.95-0.99<o:p></o:p></p>
</td>
</tr>
<tr style="height: 15.0pt; mso-yfti-irow: 3;">
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 116.0pt;" valign="bottom" width="155">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">Broadcast (liquid)<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 124.0pt;" valign="bottom" width="165">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">No Incorporation<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 178.5pt;" valign="bottom" width="238">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">0.75-0.90<o:p></o:p></p>
</td>
</tr>
<tr style="height: 15.0pt; mso-yfti-irow: 4;">
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 116.0pt;" valign="bottom" width="155">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">Broadcast (solid)<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 124.0pt;" valign="bottom" width="165">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">No Incorporation<o:p></o:p></p>
</td>
<td nowrap="" style="height: 15.0pt; padding: 0in 5.4pt 0in 5.4pt; width: 178.5pt;" valign="bottom" width="238">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">0.70-0.85<o:p></o:p></p>
</td>
</tr>
<tr style="height: 15.0pt; mso-yfti-irow: 5; mso-yfti-lastrow: yes;">
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 15.0pt; mso-border-bottom-alt: solid windowtext .5pt; padding: 0in 5.4pt 0in 5.4pt; width: 116.0pt;" valign="bottom" width="155">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">Irrigation<o:p></o:p></p>
</td>
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 15.0pt; mso-border-bottom-alt: solid windowtext .5pt; padding: 0in 5.4pt 0in 5.4pt; width: 124.0pt;" valign="bottom" width="165">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">No Incorporation<o:p></o:p></p>
</td>
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 15.0pt; mso-border-bottom-alt: solid windowtext .5pt; padding: 0in 5.4pt 0in 5.4pt; width: 178.5pt;" valign="bottom" width="238">
<p align="center" class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in; text-align: center;">0.60-0.75<o:p></o:p></p>
</td>
</tr>
</tbody></table><p align="center" class="MsoNormal" style="text-align: center;"><b style="mso-bidi-font-weight: normal;"><br /></b></p><p align="center" class="MsoNormal" style="text-align: center;"><span style="color: #0e101a; font-family: "Times New Roman", serif; font-size: 12pt; text-align: justify;">Iowa nitrogen
management recommendations either come from the Yield Goal Method or the
Maximum Return to Nitrogen concept. In the Yield Goal Method. As a base case
for comparison, I will look at deep-pit swine manure testing at 50 lbs/N per
1000 gallons. In Iowa, the average yield times 1.1 is 215 bushels/acre of corn
and 56 bushels/acre of soybean. Assuming a nitrogen use factor of 1.2 lb
N/expected bushel of corn and a soybean credit of 50 lb N/acre, nitrogen
application rates would be 208 lb N/acre to the corn phase of a corn-soybean
rotation and 258 lb N/acre in a continuous corn rotation. The Corn nitrogen
calculator would be 140 lb N/acre in a corn-soybean rotation and 188 lb N/acre
in a continuous corn rotation. I'll show a figure of these results in just a
second, but I also wanted to compare them to two neighboring states, Illinois
and Minnesota. Second-year N availability was estimated in the continuous corn
rotation as what didn't mineralize the first year.</span></p><div align="center"><div style="text-align: left;">
<p class="MsoNormal" style="line-height: normal; margin-bottom: 0.0001pt; text-align: justify;"><span style="color: #0e101a; font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";"> </span><span style="color: #0e101a; font-family: "Times New Roman", serif; font-size: 12pt;">Illinois uses the same
nitrogen volatilization recommendations as Iowa (they come from Midwest Plan
Service) and uses the Midwest plan service method to estimate nitrogen
availability from the manure. For swine manure with approximately 70% of the
nitrogen in the ammonia form and a 35% mineralization factor, 80% of the
nitrogen will be available in the first year. The second-year availability for
the continuous corn rotation is estimated to be half of the amount mineralized
from the organic nitrogen fraction, which amounts to approximately 2 pounds.
The desired Nitrogen application rate for Illinois is selected using MRTN, but
rather than the optimum value, the maximum within a $1 profit is recommended.</span></p>
<p class="MsoNormal" style="line-height: normal; margin-bottom: 0.0001pt; text-align: justify;"><span style="color: #0e101a; font-family: "Times New Roman", serif; font-size: 12pt;">Minnesota suggests
that 150 plant available pounds of N per acre should be applied in a corn-soybean
rotation and 195 in a continuous corn rotation. In Minnesota, they don't
separate corrections for availability and loss but incorporate both into a
correction factor. They also provide a second-year availability factor of 15%
for swine manure.</span></p>
<p class="MsoNormal" style="line-height: normal; margin-bottom: 0.0001pt; text-align: justify;"><span style="color: #0e101a; font-family: "Times New Roman", serif; font-size: 12pt;">What does this mean? I
put together this figure of nitrogen application rate recommendations, two for
Iowa (Yield Goal and MRTN), to compare the suggested rates for Minnesota and
Illinois. Note this is only for nitrogen and doesn't consider any phosphorus limitations
that may restrict manure application.</span></p></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgFlITVFdJpCxA2A1dkxWLftWsPmixcfnoShkKE-pl0TT3mb5VbXpvEbu8uQhNqTkdz6-ynL_Ssdfbi2fC1-tZ5Tlvh7IVw_i5JlAw6Jfhr6SOYRF_Ev6zKrIRCeoCWm4U-LAt8vJWLkA4/s676/Fig1.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="483" data-original-width="676" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgFlITVFdJpCxA2A1dkxWLftWsPmixcfnoShkKE-pl0TT3mb5VbXpvEbu8uQhNqTkdz6-ynL_Ssdfbi2fC1-tZ5Tlvh7IVw_i5JlAw6Jfhr6SOYRF_Ev6zKrIRCeoCWm4U-LAt8vJWLkA4/s320/Fig1.png" width="320" /></a></div><br /><div style="text-align: center;"><b>Figure 1. Summary of recommended manure application rates for the corn
phase of a corn—soybean rotation. Swine manure with 50 lb N per 1000 gallons,
70% ammonium with error bars set based on high and low suggestions for nitrogen
availability and volatilization losses suggested within each state.</b></div>
<p class="MsoNormal" style="text-align: center;"><o:p> <a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhyeyaF4Ram0cAQlMbGV0CjnjXadwF4xM-Jp_ysi32ViE2o-9tMPd2HBJyif3DE3At7r7q5Sb-hVRpKCiMqCtFpKfbeRC1LKRN7iOTXwQBi-RD2PR6azrKstzb9S3CrsztjW6o1BB8ICxk/s676/Fig2.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="484" data-original-width="676" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhyeyaF4Ram0cAQlMbGV0CjnjXadwF4xM-Jp_ysi32ViE2o-9tMPd2HBJyif3DE3At7r7q5Sb-hVRpKCiMqCtFpKfbeRC1LKRN7iOTXwQBi-RD2PR6azrKstzb9S3CrsztjW6o1BB8ICxk/s320/Fig2.png" width="320" /></a><br /><b>Figure 2. Summary of recommended manure application rates for a
continuous corn rotation. Swine manure with 50 lb N per 1000 gallons, 70%
ammonium with error bars set based on high and low suggestions for nitrogen
availability and volatilization losses suggested within each state.</b></o:p></p>
<p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><span style="color: #0e101a; font-family: "Times New Roman",serif; font-size: 12.0pt; mso-fareast-font-family: "Times New Roman";"> </span><span style="color: #0e101a; font-family: "Times New Roman", serif; font-size: 12pt;">As we look at this
data, I came home with a few takeaways. The first being, the factor ammonia
loss with broadcast application in Minnesota is much higher than in Iowa and
Illinois, based on the Midwest Plan Service Methods. Iowa and Illinois have
volatilization factors of 15-30%, while Minnesota uses ~45%. The difference in
volatilization assumption makes a substantial change in the recommended
application rate.</span></p>
<p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><span style="color: #0e101a; font-family: "Times New Roman", serif; font-size: 12pt;">The two
recommendations for Iowa make an interesting comparison. When using the yield
goal approach, Iowa's recommendations are similar to those provided with the
Illinois method. In the case of continuous corn, the Yield Goal method for Iowa
tends to be slightly higher, while in the corn-soybean rotation marginally
lower, but overall, the results are similar.</span></p>
<p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><span style="color: #0e101a; font-family: "Times New Roman", serif; font-size: 12pt;">When we look at the
recommendations resulting from using the MRTN for Iowa, the results are more
comparable to the Minnesota recommendations. In the corn-soybean phase, Iowa's
MRNT recommendation would be lower thanks to both the lower mineralization
suggestion and the slightly higher N application recommendation.</span></p>
<p class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0in;"><span style="color: #0e101a; font-family: "Times New Roman", serif; font-size: 12pt;">Overall, these results
indicate that Iowa's approaches place us within the context of the surrounding
states.</span></p></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><br /></div></div><div style="text-align: center;"><p class="MsoNormal" style="line-height: normal; margin-bottom: 0.0001pt; text-align: justify;"><span style="color: #0e101a; font-family: "Times New Roman", serif; font-size: 12pt; text-align: left;"><br /></span></p><div style="text-align: justify;"><br /></div></div>Daniel Andersenhttp://www.blogger.com/profile/17296164974381593950noreply@blogger.com0tag:blogger.com,1999:blog-8695306981003495902.post-56364245633735870862020-05-21T16:21:00.001-05:002020-05-21T16:21:20.000-05:00Shallow Burial for Mass Mortality Management<br />
<div class="MsoNormal" style="line-height: normal; mso-margin-bottom-alt: auto; mso-margin-top-alt: auto;">
<span style="color: black; font-family: "Arial",sans-serif; font-size: 10.0pt; mso-fareast-font-family: "Times New Roman";">There is no best way to
dispose of swine mortality carcasses. While some methods may work well for
managing routine mortalities, due to capacity issues, they may not adapt to
times when catastrophic mortalities occur. The optimum system for any
particular farm location is based on a number of criteria, including the
current state of the protein/oil market, the biosecurity required, the distance
to processing sites, the local public's perception, the government regulations
that apply to that location, the environmental conditions, and the ability of
the farm to carry out the different procedures. <o:p></o:p></span></div>
<div class="MsoNormal" style="line-height: normal; mso-margin-bottom-alt: auto; mso-margin-top-alt: auto;">
<span style="color: black; font-family: "Arial",sans-serif; font-size: 10.0pt; mso-fareast-font-family: "Times New Roman";">The death losses at a
farm can be classified broadly as one of two types: <span style="mso-spacerun: yes;"> </span>routine or catastrophic mortalities. Routine
mortalities represent a small proportion of the herd and occur throughout normal
production. Catastrophic mortality events involve high death losses within a
distinct time. Four predominant methods of routine swine mortality disposal are
burial, incineration, rendering, and compositing. Catastrophic losses present
unique challenges because of handling large amounts carcasses within a short
time (and if losses are due to disease, a higher biosecurity risk).<o:p></o:p></span></div>
<div class="MsoNormal" style="line-height: normal; mso-margin-bottom-alt: auto; mso-margin-top-alt: auto;">
<i style="mso-bidi-font-style: normal;"><span style="color: black; font-family: "Arial",sans-serif; font-size: 10.0pt; mso-fareast-font-family: "Times New Roman";">Burial<o:p></o:p></span></i></div>
<div class="MsoNormal" style="line-height: normal; mso-margin-bottom-alt: auto; mso-margin-top-alt: auto;">
<span style="color: black; font-family: "Arial",sans-serif; font-size: 10.0pt; mso-fareast-font-family: "Times New Roman";">Burial can occur either
on site or via transport of carcasses to approved landfills. Typically, on-farm
burial of routine mortalities is performed using a trench method, which
involves excavating a narrow and shallow trench, placing a single layer of
carcasses in the trench and then covering with soil. Pigs slowly decompose
until they are unrecognizable, generally after a few years. One concern is that
burial can have negative environmental impacts if the sites are not selected
carefully. In particular, depth to groundwater or sanding soils where leachate
transport to groundwater is more likely. This method is not available when the
ground is frozen and predators can uncover carcasses not buried deep enough.
Typically, for routine management of mortalities, this method is often reserved
for smaller operations.<o:p></o:p></span></div>
<div class="MsoNormal" style="line-height: normal; mso-margin-bottom-alt: auto; mso-margin-top-alt: auto;">
<span style="color: black; font-family: "Arial",sans-serif; font-size: 10.0pt; mso-fareast-font-family: "Times New Roman";">In terms of catastrophic
mortality, disposal burial is more common. With emergency disposal burial, the
number of carcasses placed in a location is typically greater, increasing the
potential for leachate, making location selection critical. The use of modern
engineered landfilled equipped with leachate collection and treatment
significantly reduces the risk of leachate concerns. The utilization of the
landfill relies on the owner’s copperation and the transport of carcasses. Efforts
to support bio-secure transport are required in cases where mortality is from a
transmittable disease.<o:p></o:p></span></div>
<div class="MsoNormal" style="line-height: normal; mso-margin-bottom-alt: auto; mso-margin-top-alt: auto;">
<span style="color: black; font-family: "Arial",sans-serif; font-size: 10.0pt; mso-fareast-font-family: "Times New Roman";">If mass burial is
required on site, the combination of topographic, geologic, soil, and water
resource data should be used to identify and map burials sites. Farms should
work to identify locations for on-farm burial as part of emergency preparedness
plans.<o:p></o:p></span></div>
<div class="MsoNormal" style="line-height: normal; mso-margin-bottom-alt: auto; mso-margin-top-alt: auto;">
<i style="mso-bidi-font-style: normal;"><span style="color: black; font-family: "Arial",sans-serif; font-size: 10.0pt; mso-fareast-font-family: "Times New Roman";">Shallow Burial<o:p></o:p></span></i></div>
<div class="MsoNormal">
Shallow burial is a bit different, almost a cross between
composting and burial. Often burial decomposition is slowed by lower oxygen
concentrations and the fear of leachate movement. Shallow burial tries to
address this by leaving the carcass near the surface.<o:p></o:p></div>
<div class="MsoNormal">
The process is something like this – dig a long narrow
trench approximately 20-inches deep by the width of an animal body for the
length you need. You’ll want to put in a layer of organic material, like wood
chips, approximately 12-inches thick. This absorbent material will help absorb
any potential leachate from the animals and also can help facilitate air
exchange and keep the zone aerobic.<o:p></o:p></div>
<div class="MsoNormal">
The next step is to get the animals in the trench, one layer
thick. The animals are probably mostly even with the ground. What we are trying
to do with this approach is keep them in an area with high soil microbial
activity to help promote decomposition. At this point, put the removed soil
back on top, plant grass or perennial vegetation to keep it in place, and let
nature help with the circle of life.<o:p></o:p></div>
<div class="MsoNormal">
It will take a little time, but most work has shown in about
a year, the animal’s decomposition will be nearing completion.<o:p></o:p></div>
<div class="MsoNormal">
If you are looking into what you might need to get started
on the process Michigan State has a spreadsheet to help you plan sizes and
material needs. <a href="https://www.canr.msu.edu/resources/spartan-emergency-animal-tissue-composting-planner-v1-04">https://www.canr.msu.edu/resources/spartan-emergency-animal-tissue-composting-planner-v1-04</a>.<o:p></o:p></div>
<br />Daniel Andersenhttp://www.blogger.com/profile/17296164974381593950noreply@blogger.com0tag:blogger.com,1999:blog-8695306981003495902.post-68606942820101633332019-12-23T13:18:00.003-06:002019-12-23T13:18:32.188-06:00The Value of Adding Small Grains and Hays to Improve Manure Management in Iowa<br />
<div style="margin-bottom: .0001pt; margin: 0in;">
<span style="color: #201f1e; font-family: "calibri" , sans-serif; font-size: 11pt;"><o:p> </o:p></span><span style="color: #201f1e; font-family: "calibri" , sans-serif; font-size: 11pt;">Annual manure production in
Iowa now exceeds 14 billion gallons of liquid manure, with most of this
predominately produced on swine farms. This manure needs to be applied annually
and its management is often cited as one of the critical factors impacting
water quality. Some research suggests, this is in part to a mismatch in timing
of when crop nutrients are needed and when the manure is applied. Moreover,
unlike other fertilizer sources, the management of manure is complicated by the
fact specific management activities at the facility does not always align with
the most appropriate agronomic decisions. For example, manure application could
be driven by a full storage rather than appropriate field conditions, or a turn
at the facility that allows manure agitation and removal at a time when the
facility is empty, improving withdrawal safety for employees and animals.</span></div>
<div style="margin-bottom: .0001pt; margin: 0in;">
<br /></div>
<div style="margin-bottom: .0001pt; margin: 0in;">
<span style="color: #201f1e; font-family: "calibri" , sans-serif; font-size: 11.0pt;">Moreover, given the predominately
row crop (corn/soybean) agriculture that typifies much of the corn belt, manure
application windows are typically limited to either spring after the soil thaws
but before planting occurs or fall after harvest but again before the soil
freezes. While these windows have typically proven sufficient, changing weather
patterns, the expansion of livestock agriculture, and the separation of
ownership of the cropping and livestock production portions of the operation
have put new and greater stresses on the way the system is managed.
Furthermore, the move from independent ownership of manure application
equipment at the farm level, to a system where it is owned by an independent
contracting business has taken much of the control away from the individual farmer
and created a system.<o:p></o:p></span></div>
<div style="margin-bottom: .0001pt; margin: 0in;">
<br /></div>
<div style="margin-bottom: .0001pt; margin: 0in;">
<span style="color: #201f1e; font-family: "calibri" , sans-serif; font-size: 11.0pt;">In a system based on single
ownership of the crop and livestock facility, the decision when to apply manure
was a compromise for both the cropping production system and the livestock
production side, with the farm manager typically wanting to balance the
decision to maximize overall farm profits. There is great incentive to
optimally manage manure as a fertilizer resource with more ideal application
timing, but not to the extent it would prohibit the production of livestock. If
the storage was full, there is incentive to perform emergency manure
application, so animals could continue to be raised in the production facility.
Since these farms often owned their manure application this would typically
occur only to draw down the storage to an adequate level until more appropriate
application timing.<o:p></o:p></span></div>
<div style="margin-bottom: .0001pt; margin: 0in;">
<br /></div>
<div style="margin-bottom: .0001pt; margin: 0in;">
<span style="color: #201f1e; font-family: "calibri" , sans-serif; font-size: 11.0pt;">However, in more modern setups
where ownership of the crop and livestock is divided among different
individuals, there are competing interests in different decisions. For example,
the crop farmer still would want optimum timing for crop performance, but the
barn owner often focuses his decision process solely on what is best in terms
of barn management. When the fields open up, the livestock farmer may find
themselves in a situation where they may be giving away or selling the manure
at far below the market value of the nutrients it contains. This, in turn,
allows the crop producer to view it as a free fertilizer only minimally impacts
his other fertility decisions. While from an economic perspective this
arrangement is perhaps beneficial to both parties, it also creates a situation
where the environmental constraints on the system are not given priority.<o:p></o:p></span></div>
<div style="margin-bottom: .0001pt; margin: 0in;">
<br /></div>
<div style="margin-bottom: .0001pt; margin: 0in;">
<span style="color: #201f1e; font-family: "calibri" , sans-serif; font-size: 11.0pt;">This, along with the rising
costs of manure application machinery, is putting the equipment out of reach
for many farms. Thus, the greater stress to get all manure applied in shorter time
windows. While I don’t have the answers on this, it is important as we go about
facing these challenges, we look at all the options – new crop rotations,
bigger and faster equipment, altering our manure management systems to make
within season application possible, and potentially numerous others. It seems
like a first step is to understand how different crops may open up new
application windows, a first attempt at that, which I’ve shown below. Note: I’m
not saying we need to have lots of acres devoted to other crops, the next fun
steps are figuring out how much will be enough.<o:p></o:p></span></div>
<br />
<br />
<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj_7rPyTlYPIlYXUDdxW-QzTD97Ejg5d8KkAT_qh4AHFKWpMJzRV7pNcu_BOfyUOtCkyKH9rbrulmupXdUgJTCUliPq-9w1eq3ICZM0x86i8msj85AZMl8Hh8HUKHQ2my1VgXGjsxv-Ols/s1600/figure1.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="118" data-original-width="624" height="120" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj_7rPyTlYPIlYXUDdxW-QzTD97Ejg5d8KkAT_qh4AHFKWpMJzRV7pNcu_BOfyUOtCkyKH9rbrulmupXdUgJTCUliPq-9w1eq3ICZM0x86i8msj85AZMl8Hh8HUKHQ2my1VgXGjsxv-Ols/s640/figure1.png" width="640" /></a></div>
<div style="margin: 0in 0in 0.0001pt; text-align: center;">
<span style="color: #201f1e; font-family: "calibri" , sans-serif; font-size: 11.0pt;">Figure 1. Cropping activity
windows for different crops in Iowa.<o:p></o:p></span></div>
<br />Daniel Andersenhttp://www.blogger.com/profile/17296164974381593950noreply@blogger.com0tag:blogger.com,1999:blog-8695306981003495902.post-2259147261545220252019-11-26T11:23:00.000-06:002019-11-26T11:23:00.585-06:00The Science Behind Manure Management Plans - Nitrogen<div class="separator" style="clear: both; text-align: center;">
</div>
<div class="separator" style="clear: both; text-align: center;">
</div>
<div class="separator" style="clear: both; text-align: center;">
<br /></div>
<br />
<div class="MsoNormal">
Manure management plans are a tool used by both the farm to
make sure they are getting the most from their manure and by society to ensure
manures are managed in a way that is appropriate and only allows acceptable
risk to environmental quality. I think we can all agree these are good things
we want to occur but like most things, the devil is in the details. How do we,
as a society and individual farmers, work to select the right nutrient
application rates to balance both fertility decisions and impacts on yields and
economics, with the potential environmental consequence?<o:p></o:p></div>
<div class="MsoNormal">
In most manure plans, the yield goal method is used to
define the maximum allowable nitrogen application rate. This approach is based
on a mass balance approach where we are trying to match nitrogen application
rates to removal and loss rates. In this sort of system, there is a fair amount
of uncertainty in understanding where nitrogen ends up and how it moves. Changes
in corn genetics have impacted how the existing factors in this equation may
interact. Below I’ve constructed a partial nitrogen budget (estimate N
application using the yield goal method minus the amount removed in grain) with
two different grain nitrogen content. The old budget uses the 0.8 lb N/bu of
grain which is what is listed on the USDA crop nutrient removal tool, while the
newer partial budget uses 0.6 lb/N bu of grain which is just a bit higher than
what newer research on corn nitrogen suggests is occurring. I’ve also marked
two vertical lines; the gray line represents Iowa’s corn yield in 1995 (state
average) while the black line represents Iowa’s corn yield in 2018.<o:p></o:p></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
What should we be taking away from this information? It
isn’t that the yield goal method is archaic, but rather, as corn genetics have
changed we need to be thoughtful about how it impacts the nitrogen use
coefficients listed for different crops within the document. It is possible, at
some point, these will need to be updated and deciding when, how, and what is
the right factor is critical to providing a realistic yield estimate. While
there is a lot to the nitrogen cycle and it can get a bit confusing, there are
two things to note in this figure. The first is the two lines diverge from each
other at yields get higher and the second is over the last 25 years the yields
have greatly increased.<o:p></o:p></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
So what does this mean at the 1995 yield level? The old
partial N budget application approximately matched the removal in corn grain.
If we look to current yields, even at the old corn N removal rate, we were
putting on around 25 lb N/acre more nitrogen than would be removed in the
grain, but as grain nitrogen content has come down, this amounts to about 40 lb
N/acre.<o:p></o:p></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
So what does this really mean? While the yield goal method
is based on a mass balance approach for nitrogen, many of the factors in mass
balance are hard to predict. Thinking about how our agricultural systems have
changed over time and what this means for rate selection, is critical for
making an informed decision. Moreover, this is one of the reasons Iowa State
has switched to recommending the maximum return to nitrogen approach for rate
selection.<o:p></o:p></div>
<div class="MsoNormal">
<br /></div>
<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjnWs2tEJEL_54RQXGUqZtU6jugFoAfiOTSa9VfiNBZ0l4LvZ-0j9mYhse4kNTGZPvKbyOlOFjuXIpVUU0vXzZDdindgClfS1rJUCIx_RLkNeeK0Oe0U5NzabRSf9iq_4504fh0ll1PD-c/s1600/budget.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="288" data-original-width="480" height="192" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjnWs2tEJEL_54RQXGUqZtU6jugFoAfiOTSa9VfiNBZ0l4LvZ-0j9mYhse4kNTGZPvKbyOlOFjuXIpVUU0vXzZDdindgClfS1rJUCIx_RLkNeeK0Oe0U5NzabRSf9iq_4504fh0ll1PD-c/s320/budget.png" width="320" /></a></div>
<div align="center" class="MsoNormal" style="text-align: center;">
Figure 1. <span style="mso-spacerun: yes;"> </span>Partial nitrogen budgets (input – grain N
removal) for old (corn with 0.8 lb N/bu) and new (corn with 0.6 lb N/bu)
estimates. The vertical gray line represents corn yield in 1995, while the
vertical black line represents corn yield in 2018. Representation for a corn
soybean rotation with a soybean credit (rotation effect) of 50 lb N/acre)<o:p></o:p></div>
<br />Daniel Andersenhttp://www.blogger.com/profile/17296164974381593950noreply@blogger.com0tag:blogger.com,1999:blog-8695306981003495902.post-2771225018430405952019-10-24T08:40:00.002-05:002019-10-24T08:40:28.153-05:00Manure Management Plans – What are they?<br />
<div class="MsoNormal">
Manure, waste or resource, is a question I like to ask when
I get the chance to step in front of a class and hear what students have to
think about the topic. Generally, I get enough answers of both to be satisfied.
Manure can be a waste and it can be a resource: it comes down to how we manage
it. It is a simple answer, but the best ones often are.</div>
<div class="MsoNormal">
<br /></div>
<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhAqoTsJATJXgRFE63be99YHn8HWhHsfbx2RtBpEgZGvbCleyKOiQ-P-p9DWd3jgZD9qhyphenhyphenPvOIoAOAx0QpR7OIOnwPm3FpnpksaZ-NOAvEzx-K2YMVeFVAkWNqc2UBbzC24a9J0kqhnZwg/s1600/MMP+Rate+2.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="854" data-original-width="1280" height="213" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhAqoTsJATJXgRFE63be99YHn8HWhHsfbx2RtBpEgZGvbCleyKOiQ-P-p9DWd3jgZD9qhyphenhyphenPvOIoAOAx0QpR7OIOnwPm3FpnpksaZ-NOAvEzx-K2YMVeFVAkWNqc2UBbzC24a9J0kqhnZwg/s320/MMP+Rate+2.jpg" width="320" /></a></div>
<div class="separator" style="clear: both; text-align: center;">
1. Students work to develop a manure management plan for a beef operations.</div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<o:p></o:p></div>
<div class="MsoNormal">
So what is a manure management plan? This is a tool that
estimates all the manure a facility is going to generate and then looks at the
crop fields available to make a determination about how much manure could be
applied to each field in any given year, based on both the risk of phosphorus
transport and the nitrogen needs of the crop. In the state of Iowa, they are
required for confinement animal feeding operations with more than 500 animal
units, which is 1,250 finishing pigs. Manure management plans can serve as a
tool for the farm as a means to estimate manure application rates, but also a
tool for society to ensure the farm has the capacity to manage its manure in a
way based on legal standards we have defined as environmentally acceptable.<o:p></o:p></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
The original framework for these plans was developed in the early
1990’s and has been modified slightly. The livestock and the manure industry
looked a bit different at those times. For example, manures typically had about
$8-$12 per 1000 gallons nutrient value in it, whereas now we typically average
closer to $30. While this change may not sound like much, when compared to
typical application prices of $10-$20 per 1000 gallons, those differences can
make a world of difference, changing it from a fertilizer source that isn’t
cost effective for the farmer to utilize to one that is.<o:p></o:p></div>
<div class="MsoNormal">
When manure plans were first developed, some farms manure looked
like a product we had to dispose and find a way to manage, while minimizing
environmental risk. Today, we have a greater opportunity, manure can be a
resource, if we can find ways to manage it as such. Are the production systems
we use today perfect? No, none are. We need to continue to get better and
improve them to ensure livestock farms can remain an important part of our
landscape in the future. We have made progress, and have to continue to do so
in the future.<o:p></o:p></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
Manure management plans are typically filled out using the yield
goal method. In this method, farmers determine a yield goal for each of their
fields. This is a number selected based on previous yields either for that
field or that county, and then multiplied by a nitrogen use factor, typically
1.2 lb N/bu of corn yield expected, less any legume credits their field would
have. Is this method perfect? No. I’ve expressed different thoughts about it
before. <a href="http://themanurescoop.blogspot.com/2019/03/yield-goal-and-mrtn-look-at-what-these.html">In
a previous blog</a>, I compared how yield goal method and MRTN estimates
nitrogen application rates, looking at how corn nitrogen content per bushel has
changed and what it means for these methods. In <a href="http://themanurescoop.blogspot.com/2016/11/update-yield-goal-compared-to-maximum.html">this
blog</a>, I looked at how the estimates compared in each county. However, nitrogen
application is a complicated topic, related to weather, and soils, and timing,
and there is a lot that goes into this decision.<o:p></o:p></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
Is there room for improvement? Absolutely! Take credit for
those nutrients. Get manure to fields where all the nutrients have value. Work
to minimize uncertainty in nutrient supply by testing the manure for nutrient
content, calibrate the equipment and check the flow meter. Look at application
uniformity, inject or incorporate, and try to apply at appropriate times. Will
this alone solve our water quality concerns? No, but they are things we can do
now to maximize the value of manure in our operations and take steps towards
environmental improvements and continuing to build trust in using manure
nutrients.<o:p></o:p></div>
<br />Daniel Andersenhttp://www.blogger.com/profile/17296164974381593950noreply@blogger.com0tag:blogger.com,1999:blog-8695306981003495902.post-5705899328368590682019-09-11T16:45:00.000-05:002019-09-11T16:45:06.560-05:00Manure Application Timing<br />
<div class="MsoNormal">
I’ve previously talked about nitrogen rate selection, using
either the yield goal method or maximum return to nitrogen, and what that may
mean from both a production and nutrient use standpoint. This time we are going
to do something similar, but will look at a different aspect of it, the impact
of when the nitrogen gets applied and how that may impact where it ends up.<o:p></o:p></div>
<div class="MsoNormal">
The nitrogen cycle is complex; there is a lot going on and
it is highly weather dependent – temperature, soil moisture, rainfall, and biology
of plants and microbes. So at best, this is an incomplete nitrogen budget as not
all sources of nitrogen are going to be accounted for as no measurement of soil
nitrogen mineralization was made. Similarly, all the places nitrogen could end
up aren’t measured, such as the amount of ammonia lost to volatilization, or
nitrogen that ends up as N<sub>2</sub>O or N<sub>2</sub>, or the amount
accumulated in soil organic matter. At best, this is a partial budget that
looks at the amount of nitrogen ending up in tile water and in the crop.<o:p></o:p></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
So we are going to take a look at four treatments:<span style="mso-spacerun: yes;"> </span>1) Spring UAN (corn-soybean rotation, chisel
plow and field cultivate, N rate at 150 lb/acre to corn phase), 2) Early Fall
Manure (corn-soybean rotation, no till, N rate at 150 lb/acre to corn phase as
liquid swine manure in early to Mid-October), 3) Early Fall Manure with Cover
Crop (corn-soybean rotation, no till, N rate at 150 lb/acre to corn phase as
liquid swine manure in early to Mid-October), and 4) Late Fall Manure
(corn-soybean rotation, no till, N rate at 150 lb/acre to corn phase as liquid
swine manure in early to Mid-November).<o:p></o:p></div>
<div class="MsoNormal">
As a first step, let’s take a look at average corn yield for
these treatments between 2016 through 2018. On this figure, the first thing
that stands out is the nitrogen application timing played a big role in the
actually yield, with spring applied UAN out yielding late fall applied manure
by around 35 bushels per acre and late fall manure out yielding early fall
applied manure by around 40 bushels per acre on average. No difference in yield
was seen between the early applied manure with and without cover crop (the
cover crop in this case was cereal rye).<o:p></o:p></div>
<div class="separator" style="clear: both; text-align: center;">
</div>
<br />
<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgL1iGAMPUKJOl_2iHzhSiy-sXdXvmlR5NnmjCxpiLXrLCjzp0noPgXFZdJUidjb_SDm2v_srYpYX0fmEUD2pX0hGihlWXr7KhE42-MeStMgxZVV5EVHxIm1bNa-Xzk2YOVDKEnbsRGDCw/s1600/Figure+1.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="288" data-original-width="480" height="192" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgL1iGAMPUKJOl_2iHzhSiy-sXdXvmlR5NnmjCxpiLXrLCjzp0noPgXFZdJUidjb_SDm2v_srYpYX0fmEUD2pX0hGihlWXr7KhE42-MeStMgxZVV5EVHxIm1bNa-Xzk2YOVDKEnbsRGDCw/s320/Figure+1.png" width="320" /></a></div>
<div align="center" class="MsoNormal" style="margin-bottom: 6.0pt; text-align: center;">
<b style="mso-bidi-font-weight: normal;"><span style="font-size: 10.0pt; line-height: 107%; mso-bidi-font-family: Calibri; mso-bidi-font-style: italic; mso-bidi-theme-font: minor-latin;">Figure 1. Average yield data for 2016 through 2018 crop years for corn
in corn-soybean rotation with differing fertilization treatments (EFM – Early
to mid-October manure application, EFM+CC- Early to mid-October manure
application and a cereal rye cover crop, LMF- Early to mid-November manure
application, UAN – spring UAN fertilizer application). All plots received 150
lb N/acre.<o:p></o:p></span></b></div>
<div class="MsoNormal" style="margin-bottom: 6.0pt;">
<br /></div>
<div class="MsoNormal" style="margin-bottom: 6.0pt;">
A second way to think of this
data as what percent of the maximum yield was obtained and what this means for
nitrogen utilization efficiency of the fertilizer source. One way to think about
and visualize this data is as a function of where we fall on a typical yield
response curve. While this curve looks different from year to year, I’m going
to use the state average data yield response curve to look at and interpret
what this means. The blue diamond shows the spring UAN application and suggests
that it would have achieved 99% (or a little better than) of maximum yield. The
late fall manure achieved about 84% of maximum yield and would have been
equivalent to about 70 pounds of spring applied nitrogen fertilizer, while the
early fall manures achieved about 67% of maximum yield and was similar in value
to approximately 10 lb N/acre fertilizer application. I’ve marked these two
points on the curve in Figure 2 with red dots.<span style="font-size: 10.0pt; line-height: 107%; mso-bidi-font-family: Calibri; mso-bidi-font-style: italic; mso-bidi-theme-font: minor-latin;"><o:p></o:p></span></div>
<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEglbaPRRQbUsf0SIdSRKbamJCU-6rCNAG49D1zPuCHvq3p4iv0W3QwpcnKugjB1A8eGgn9jhVMmG4x9D0FvVipEJ7pYIXltsVPCQhFVp41VLuv8W82bBnaRPbcnFT5m3sF63SwXjkVnwgU/s1600/Figure+2.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="561" data-original-width="790" height="227" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEglbaPRRQbUsf0SIdSRKbamJCU-6rCNAG49D1zPuCHvq3p4iv0W3QwpcnKugjB1A8eGgn9jhVMmG4x9D0FvVipEJ7pYIXltsVPCQhFVp41VLuv8W82bBnaRPbcnFT5m3sF63SwXjkVnwgU/s320/Figure+2.png" width="320" /></a></div>
<div align="center" class="MsoNormal" style="margin-bottom: 6.0pt; text-align: center;">
<b><span style="font-size: 10.0pt; line-height: 107%; mso-bidi-font-family: Calibri; mso-bidi-font-style: italic; mso-bidi-theme-font: minor-latin;">Figure 2. Looking at a typical yield response curve to understand the
effectiveness of manure fertilizer in this study. The blue diamond represents
spring UAN, the red circles represent Late Fall Manure and Early Fall Manure
applications respectively.</span></b></div>
<div class="MsoNormal" style="margin-bottom: 6.0pt;">
Looking at the next part, what
did this mean for nitrate concentrations in the tile drainage water? In many
ways, the results tended to mirror what we saw from the yield numbers, with one
notable exception. Places where yield was higher tended to have lower nitrate
concentration. The exception to this was the cover crop plots, where despite
having lower yield, nitrate concentrations in the tile drainage remained low.
The other thing of note was, in general, early fall and late fall manure showed
more variability from year to year, indicating it doesn’t always increase loss,
as much as it increases the chance of loss.<b style="mso-bidi-font-weight: normal;"><span style="font-size: 10.0pt; line-height: 107%; mso-bidi-font-family: Calibri; mso-bidi-font-style: italic; mso-bidi-theme-font: minor-latin;"><o:p></o:p></span></b></div>
<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgDsDZHrjXFx0R0Mfy_Txu-rfSBr1WdC8tsHuI8lksrAM1LOzDLPb10v0ICk5n-gUhb_kgJ8HBrjHu26I6wNFcbCpoz5yjRwicYfIx0maHvmuuJXkH-8QIxio6NiDHFPnhDj4XoDUDbTm4/s1600/Figure3.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="291" data-original-width="480" height="194" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgDsDZHrjXFx0R0Mfy_Txu-rfSBr1WdC8tsHuI8lksrAM1LOzDLPb10v0ICk5n-gUhb_kgJ8HBrjHu26I6wNFcbCpoz5yjRwicYfIx0maHvmuuJXkH-8QIxio6NiDHFPnhDj4XoDUDbTm4/s320/Figure3.png" width="320" /></a></div>
<div align="center" class="MsoNormal" style="margin-bottom: 6.0pt; text-align: center;">
<br /></div>
<div class="MsoNormal" style="margin-bottom: 6.0pt;">
<b style="mso-bidi-font-weight: normal;"><span style="font-size: 10.0pt; line-height: 107%; mso-bidi-font-family: Calibri; mso-bidi-font-style: italic; mso-bidi-theme-font: minor-latin;">Figure 3.
Average nitrate-nitrogen concentrations in tile drainage water for 2016 through
2018 crop years for corn in corn-soybean rotation with differing fertilization
treatments (EFM – Early to mid-October manure application, EFM+CC – Early to
mid-October manure application and a cereal rye cover crop, LMF – Early to
mid-November manure application, UAN – spring UAN fertilizer application). All
plots received 150 lb N/acre. <o:p></o:p></span></b></div>
<br />Daniel Andersenhttp://www.blogger.com/profile/17296164974381593950noreply@blogger.com0