Help with composting on a large-scale corn and soybean
I have just started following your column on the New Farm website. We
farm + 1000 acres of organic corn and soybeans in Iowa, and therefore
your comments about cover crops, etc., are very pertinent to us.
Have you had any experience with composting? We are just starting that
routine, due to having no time in fall or spring to truck in the turkey
litter which we use for fertilizer. Composting appears to give us the
chance to haul nearly all year, stockpile, and apply in spring, without
losing the nutrients.
The question … I would like to allow our cover crops to grow until
about May 1, at which time we would spread the compost, and incorporate
same with field cultivators. Planting corn would then begin about May
10-15. Is that 10-14 days enough time for the compost to begin to break
down, and become available? Or, do we need to spread and incorporate (which
obviously would then tear up the cover crop) nearer to April 15 in order
to allow the composted turkey litter more time to breakdown?
I have been told that oats are actually a better cover crop than the winter
rye, which we are currently using. It apparently provides more beneficial
nutrient take-ups than rye, even though rye supposedly has better weed
control properties. Another advantage for us with the winter rye is that
we can put it on in the fall, whereas spring planting of oats can be a
hit or miss operation, obviously depending upon the weather. That could
result in late planting of the oats, and resultantly, a short stand by
the time the compost needs to be applied.
Your comments will be appreciated.
Spring Valley Farms of IA, Ltd.
Good morning, Gene,
I’ll try and answer your questions but I must admit your letter
prompted more questions in my mind than answers. I’ll discuss composting
first. We do compost broiler house litter and municipal leaf waste here
on our farm. We don’t use it as our primary nitrogen source since
we have seen through our research that if we apply enough compost to satisfy
our nitrogen needs the phosphorous levels begin to be a problem. We use
legume cover crops, planted in the fall, to supply the nitrogen then apply
the compost as a source of micronutrients and “food” for the
microbes in the soil. I think you hit on something most composters will
agree with. And that is the control you get over your time at crunch periods
by not needing to haul material great distances when you want to be getting
your ground ready to plant. I think the 2 week time period you suggest
between application and planting will work out fine. The corn won’t
need the fertilizer released from the compost for another 2 or 3 weeks,
anyway, and by then it will be there. I’m curious about your rotation.
If you have time or interest to write back, I’d be interested in
learning more about your rotation, fertilizer, and overall farm plan.
The only time I use oats as a cover is as a fall planting which will then
winter kill. Often I plant oats in late summer with a vetch legume to
act as a nurse crop for winter protection. We do plant rye in the fall,
usually after soybean harvest. The biggest problem we have is handling
the lush rye growth in the spring. It sounds like you will be killing
it early enough so that it won’t be an issue. It does take a fair
amount of disturbance to actually kill it.
Are turning you compost? Do your plans involve mixing the turkey litter
with another carbon source, or is the C or N ration fine as it is?
Again thanks for reading New Farm and I look forward to hearing from you
Gene continues the conversation:
Thank you for the reply. A few comments are listed below.
About our rotation and farm plan: Right now our rotation has been
corn/bean/corn/bean, etc. Since the NOP have been installed, we have not
had to use a fallow, or small grain, crop in the rotation. As soon as
I start getting some kickback on the organic crop cash--weed control has
been disastrous up until this year--I will be putting in small grains,
probably wheat. Further, I am considering going with alfalfa if I can
find an organic market for it, which is in the realm of feasibility …
we have had so many new issues to deal with that to also get into the
haying business, with balers and storage problems, etc., might be the
straw that would send me bonkers.
About hard-to-kill rye: We have had that problem--one year the rye was
above the hood of my Suburban, and this year we let 35 acres get too tall.
Took 5--literally 5--diskings to knock it down enough to let the planters
put seeds into actual soil. We have not had much problem with re-growth.
In the future we will, at least, mow the rye timely, even if we cannot
till it under at that time. (On the 35A this spring, after 5 diskings,
I still could not see the planter markers, and had to have the field harrowed
to make it "glossy" enough for the markers to provide enough
of a line for me to not get too far off, too much of the time.
About turning our compost, and adding C: We bought a turner on a Texas
auction earlier this year, and did not have a chance to operate it until
just now, when we started needing it. Real problem … drum out of
balance, and cannot be put into balance because of the abuse it had received.
Now looking for drum builder. But, yes, we will turn it … are going
to use loader/backhoe for now. With respect to C source … we are
using turkey litter, and frankly I am not sure we are going to have to
use a C source. If we do, it will probably be sawdust.
I can relate to everything you are saying. I can tell you it does get
easier, but new problems find a way of creeping into the system. Then
again, that’s what makes life interesting. One of the operations
I’m personally focusing on is no-tilling corn into cover crops.
I built a roller to kill the cover (and it works on rye when it’s
headed out). Then I no-till plant the corn or beans. I mount my roller
on the front of the tractor and the planter on the rear as a one pass
operation. You could do it in 2 passes, in which case I plant first then
roll or roll first then use foam markers to plant by. Keep in touch.