If you are growing corn after corn, then you've got a somewhat different decision to make than if you're staying in a corn/soybean rotation. How are you going to handle the extra residue from today's high-producing hybrids and still achieve a good seedbed for corn next spring?
Tell Tony Vyn, Purdue University tillage specialist, that he is faced with growing corn-after-corn. Then ask him to list tillage systems that could best handle this situation in his eyes. Vyn assists in Purdue's long-running tillage plots at the Purdue Agronomy Research Center near West Lafayette, and also compares tillage systems in other plot work of his own.
"My first option would be to go to strip tillage," he says. "I would go in between the existing rows this fall with a strip-till rig and make the raised berms that I could plant on next spring. It's a cheaper option from the economical option than doing primary tillage this fall, then coming back with one of two secondary tillage passes next spring."
That assumes, of course, that you either already have a strip till unit, or else can find a dealer who custom strip-tills in the fall or rents out the equipment so that you can do the work yourself. And it assumes you don't have sandy soils. Vyn's first option for tillage in corn after corn on sandy soils is none - no-till next spring instead.
What if you can't get ready for strip-till this soon? "My second option for corn-after-corn residue situations would be fall disking," he says. "That would be on soils subject to erosion. If there is very little threat of soil erosion, then I would opt for moldboard plowing. It has been effective in my plots at producing better yields than chisel-plowing."
Moldboard plowing is particularly effective at producing higher yields in corn after corn on clay soils, he notes. Strip-till is the most competitive alternative. An advantage to strip-till is that it still leaves a good layer of soil residue on the surface of a good percentage of the field.