Every spring, as manure storage levels are inspected with varying degrees of optimism, the question comes up:
Can I put manure on hay ground? The short answer is “yes.” The
slightly longer answer, and the one extension specialists are paid to give, is “yes,
but it depends.”
Hay and pasture can be excellent places to use manure
nutrients. Forage crops are hungry, they respond well to nitrogen, and they
offer flexibility when row crop acres are already planted or conditions aren’t
ideal elsewhere. That said, forage stands are less forgiving than bare ground.
Unlike corn acres, where manure gets incorporated and everyone moves on with
their lives, hay fields tend to remember what you did to them (I remember that rut
from last year).
Timing matters. So does rate and so does what kind of manure
you’re hauling.
If applying to hay ground, the best timing is as soon after harvest
as possible. This gives manure the greatest chance to reach the soil surface
while giving the stand the most time to recover before the next harvest.
Applying immediately after cutting also reduces wheel traffic damage to
regrowth. Young shoots don’t appreciate being run over any more than the rest
of us.
If choosing between fields, I generally choose older hay
stands first. They’re often a little grassier, and grasses tend to respond very
well to manure nitrogen. They also tend to be more tolerant of manure
application than a young, productive alfalfa stand with crowns you’d prefer not
to bury under a layer of bedding and regret.
For liquid manure, thinner is better.
If pulling from a storage, skim from the top if you can.
This is one of the rare times in agriculture when taking only the top layer is
considered good management. Avoid full agitation before pumping. The upper
fraction is lower in solids, spreads more evenly, and is less likely to smother
regrowth. It’s also easier on alfalfa crowns.
With solids, application rate becomes especially important. A
good starting range is 5 to 10 tons per acre, with manure characteristics
driving where in that range you land. If you’ve got a thick pen-pack with a
healthy amount of corn stalk bedding still recognizable as corn stalk bedding, toward
the lower end. Coarse bedding can mat on the surface, shade regrowth, and in
heavier spots cause enough smothering to set the stand back. If manure is more
decomposed, finer textured, and spreads uniformly, rates closer to 10 tons can
work well. The key is even distribution. Most problems aren’t caused by manure,
they’re caused by a pile of manure.
Pasture generally gives a little more flexibility than hay.
Grass pastures tend to use manure nitrogen efficiently. At the end of the day,
hay and pasture can be a very good fit for manure application. They provide a
productive outlet for nutrients, they can help ease storage pressure, and they
often reward you with a little extra forage in return.
