Ask an Agronomist
Can Chopping Cornstalks Reduce Toxins Before I Plant Wheat?
Oct 20, 2011
Question: My question is have you heard anything about chopping corn stalks before planting fall wheat to help with toxins?
Answer: You’ve asked an interesting question, and I want to address it in some detail. Toxins given off by corn residue are present as long as the residue is in the field. Once the corn stalks are decomposed, the toxins disappear. I realize that by chopping the stalks you’re trying to speed up the decomposition. There are two basic reasons, in my opinion, to shed stalks: One is improve flowability of the stalks through a chisel plow. Narrow-row and twin-row corn growers commonly do this as the residue will flow through the planter better next spring when they plant, particularly for those farmers planting corn-on-corn. The second reason is to speed up decomposition. If you can speed it up, the faster you will get rid of the stalks and thereby the toxins. There is a hitch, though. In no-till wheat one of the bigger challenges, depending on where you live, is stalks drifting from the wind blowing over the field. I’ve seen chopped stalks fill up ditches and cover up the wheat and create stand problems and also harvest issues—not to mention that stalks blowing onto your neighbors’ fields won’t make them very happy. So, just shredding the stalks can be a bit risky. Crimping the stalks with your combine will help keep them in the field. If you use a chopping head and keep it high so the stalks don’t blow away, that might help. In a no-till scenario, in particular, you need to be careful with loose fodder. To get back to your specific question, my gut feeling is that it won’t make a positive difference if you shred those stalks, because your wheat crop has to start growing right now. Whether you shred the stalks or not, given the essence of time, there may not be a lot of difference in the level of toxins in the field. Also, decomposition slows down as temperatures drop, so the decomposition shifts more to the spring. I’m worried you’ll spend money on chopping the stalks now and not gain much if any advantage. Now, if you’re going to chop and bale the stalks for cattle fodder, that’s another matter. Also, if your crop rotation is corn followed by beans and then wheat, then shredding those stalks before you plant soybeans might be useful. You’ll have time then to get rid of that corn residue long before you plant wheat.
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