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.
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.
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.
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.
Figure 1. Cropping activity
windows for different crops in Iowa.
