What is in this article?:
- Corn stover harvest can benefit agronomics, finances
- Crop residue benefits soil
- Harvest rates
- Tillage reduction opportunity
- What’s it worth?
Thinking about corn stover harvest?
- Evaluate each field separately for residue harvest sustainability. Stover removal is not an option on every field, says USDA-ARS Soil Scientist Jane Johnson. “On erodible land, don’t even think about it!”
- Consult erosion and soil carbon index tools from NRCS before you make a decision. Stover harvest will be most feasible for producers achieving high yields with continuous-corn systems.
- Maintain a strong fertility testing and nutrient management program.
- Reduce or eliminate tillage and employ other soil conservation practices.
- Add a perennial or cover crop to your rotation.
Sources: Jane Johnson, USDA-ARS North Central Soil Conservation Lab, Douglas Karlen, USDA-ARS National Laboratory for Agriculture and the Environment
Tillage reduction opportunity
The Strutherses supplied 600 acres of residue to DuPont in 2013. After the stover was baled, they applied hog manure, followed by one pass with a chisel plow.
Removing some residue from continuous cornfields offers an opportunity to reduce tillage, “the biggest culprit in soil carbon loss,” Penland says. The Strutherses, for example, have switched from a disk ripper to a straight-shank ripper, which “leaves more residue on the surface to protect against erosion,” Dave Struthers says.
“We’re encouraging growers to reduce tillage intensity to save costs and work towards more conservation,” Wirt says, “which will be beneficial to both growers and the land.”
Critics of residue removal — “and there are plenty of them,” says Karlen — complain that “stover harvest increases soil erosion, sediment loss and runoff.” But he’d “trade some residue removal for less tillage. Residue removal is actually preferable to tillage for soil health,” he says. “Tillage destroys soil structure and releases soil carbon.”