Traits designed to protect cornstalks do such a good job, they can sometimes be tough to handle post-harvest. Farm Journal agronomist Ken Ferrie, based in Heyworth, Ill., urges growers in corn-on-corn rotations to carefully think through the trash issue.
Ferrie notes that when corn decomposes, it emits a toxin that can be troublesome the following spring in corn-on-corn situations. In no-till corn-on-corn, Ferrie’s studies show that the further you can plant corn away from the previous year’s crown root growth, the better your corn crop is likely to perform.
“That’s assuming you don’t have wheel track compaction from previous trips in the field,” he says. “No-till corn-on-corn leaves no room for mudding a crop in or out.”
Strip tillage can also help address light compaction as it speeds up the decomposition process. Ferrie recommends clearing the residue away when building the strip to reduce the toxin effect.
Combines play an important role in helping distribute residue evenly on fields during harvest. Shredders and spreaders that attach to the combine can even out distribution. However, in some cases, large headers on combines can create a trail of residue behind the machine.
"Shredding stalks in no-till and strip-till operations comes with a risk that they'll blow away with high winds or a flood will cause them to float away,” Ferrie cautions.
Residue management is part of a good fertility program. Ferrie says decomposition is driven by soil microbes that are very sensitive to soil pH.
“Acid soils lead to poor decomposition, so it’s important to keep soil pH balanced,” he says, adding: “Apply enough nitrogen to manage spring immobilization.”
To achieve effective nitrogen utilization for next season, he recommends that farmers split their nitrogen use into preplant, weed-n-feed and planter applications. Then, sidedress the balance of needed nitrogen, he suggests.