NEVADA, Iowa – Corn stover may be an untapped and profitable renewable resource, if farmers are able to harvest it sustainably from their fields.
A cornfield may contain more than one commodity; the corn kernels themselves, and the rest of the plant, called stover. Nevada farmer Tim Couser says combines already eject corn stover as they make passes; it’s just a matter of catching it, and baling it.
“It’s taking the part that really is of the highest value, and that we want anyway,” he says of equipment like the Hillco Single Pass Round Baler. “So it’s the corn cob, and the husk, and some leaves. The stalk is where the majority of the potassium is located, and so we want to leave that, so we don’t remove too much nutrient.”
Stover is useful in different applications: animal bedding, animal feed, and biomass for new forms of ethanol. As corn yields improve, there’s more stover in the field, and Tim’s father Bill Couser says removing some of it is in a farmer’s best interest.
“As you ride in the combine today,” says Couser, who has been farming for 40 years, “we’re seeing 300-bushel marks as we go through the field. And that’s one of the biggest challenges we have when we put our agronomic cap on; it’s residue management. It takes nutrients to break that residue down. We can safely remove – sustainably remove – a portion of that residue, so it takes less fertilizer in the spring to grow that next crop.”
The Cousers are taking part in a multi-year project between John Deere, ADM and Monsanto, who are together conducting research on handling, storage, and nutrient content of stover bales. One concern on removing stover is possible soil erosion; Monsanto End-Use Market Manager Steve Petersen says that can be avoided.
“We’ve done some analysis at various other areas around the country,” says Petersen, “looking at how… by placing a cover crop on the ground, you can protect it from erosion, you can add soil organic matter, and then it allows you to remove a lot more stover.”