Help with composting on a large-scale corn and soybean farm


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.

Thank you.
Gene Moore
Spring Valley Farms of IA, Ltd.
Oskaloosa, Iowa

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 again.


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.