You are harvesting corn, because that is what the market wants and a price is offered for it. However, the grain only amounts to 50% of the weight of the dry material in your field. Are you leaving something in the field that may have value? So far the nearest ethanol plant is not yet accepting biomass feedstock, so what is the value of that pile of dry corn stalks in the field and how can you benefit from it?

For many farmers whose fall to-do list includes chopping corn stalks, the ideas of Paul Jasa may sound like heresy, but the University of Nebraska ag engineer offers some ideas of managing corn residue to resolve some problems you may have. He says the good yields and increased volume of plant material above the soil may have created concerns about what to do with your bumper crop of corn stover, and how it will control your planting schedule next spring.

The cornhead on your combine may be one of the keys to the problem, and it will become a good partner if it can process the corn stalks by leaving them on the ground and reducing the amount of material that runs through your combine. That could be a problem for no-till farmers, but consider Jasa’s idea of leaving as much as possible of the stalk standing upright, and that reduces the amount of material between the rows that planters have to cut through next spring. Jasa is an advocate of knife to knife or tapered snapping rolls, which he says are more aggressive in lacerating and crushing stalks; and with running the combine header about a foot off the ground to leave standing stalks. While those standing stalks will deteriorate from the exposure to weather and microbes, they will also hold the rest of the residue between the rows to reduce soil erosion and preserve moisture in the spring. However, with stronger stalks that resist growing season disease and insect pressure, their winter deterioration becomes important and using the combine to jump-start that process is important.

Cornstalks that are 12-18 inches tall, left to overwinter in the field, will keep residue in place, catch snowfall, and reduce wind erosion. Jasa said air movement is enhanced down to the surface of the soil to encourage microbial breakdown of the stover, compared to matted or flat residue left with stalk choppers. However, he says the upright stalks that remain standing in the spring may get caught on planting equipment.

To clean up corn and prevent problems with volunteer corn next year, Jasa suggests grazing stalks or mechanically removing some residue, but not every year. If alternating strips of residue are removed, they should be as wide as your planter, to allow for early controlled planting next spring where the soil has warmed early.

The residue left in the field should be treated as a valuable commodity because it protects against erosion, and saves 3-5 in. of water over the year. The residue also is a valuable source of fertilizer, with each ton contributing 17 lbs of N, 4 lbs. of P, and 50 lbs. of K, and if the stover is removed, those elements need to be replaced.

The use of a cover crop will retain humidity in the crop canopy and continue the effort of residue breakdown. They will also help dry out poorly drained soils and aid to spring warm up. But Jasa says control the cover crop or it will dry out the soil and created unwanted residue.

By not using a stalk shredder, Jasa says the corn stalk is not as flattened and that will keep the opportunity for more uniform deterioration in the spring, since air and moisture can circulate.

Summary:
Some out of the box thinking about handling corn stalks may offer some new solutions to old problems. Shredding stalks will create a dense mat that will deteriorate more slowly than corn stover that allows air, water, and microbial activity. However, allowing stalks to stand will keep the biomass porous while it prevent soil erosion and retains moisture. The key to its success is the use of proper snapping rolls on a combine that will crush stalks to allow them to stand 12-18 tall, yet deteriorate over the winter to not interfere with planting progress.