Adaptability is key when new challenges throw a curveball at your no-till game plan. For Gary Kunde of Bellevue, Iowa, the combination of Bt corn hybrids that resist decay and a market signal that prompted him to plant continuous corn meant he had to find new ways to manage crop residue.
Kunde began no-tilling about 30 years ago to reduce his equipment investment. So he was ready when conservation compliance and, later, skyrocketing fuel prices came along.
"Except for the wettest years, I can no-till soybeans through undisturbed cornstalks," Kunde says. "But with corn following corn, the soil stays too cold and wet and there's too much potential for seedling diseases. I had to do something different."
After a few years, Kunde developed a four-step formula for residue management: 20" corn rows; a corn head that cuts up stalks; a shallow-spring tillage tool that sizes residue and fluffs soil to help it dry out; and row cleaners on his planter.
After switching to 20" corn rows six years ago, hoping for higher yield, Kunde found they made residue management easier. "Because you feed less material through each row, the combine header does a better job of cutting up the stalks," he says.
But the header can't handle the entire job. Kunde tried running a straight disk and a coulter tillage tool in the fall. "The disk was ineffective, and the other tool had too much weight and pulverized the surface soil too much," he says. "I concluded residue management starts at the corn head."
Kunde switched to a Drago head (www.dragotec.com) with knife-to-knife rollers. "I don't want to pulverize the stalks because the residue drifts too much," he says. "I just cut them up enough to start the decay process." A factory-installed spreader distributes residue uniformly across the width of his combine header.
Sizing residue. In the spring, Kunde runs a Great Plains Ultra-Till (www.greatplainsmfg.com) about 1" deep. "A gang of coulters on the front sizes residue, and two ranks of rolling harrows take out old root balls, fluff the residue and help the soil to dry out," he says.
The final step is clearing residue away from the planting units. "A fixed, single-tine row cleaner worked fine for planting into soybean residue," Kunde says. "But planting into cornstalks, I needed something that would move more residue and flex to follow the contour of the ground." He settled on Yetter 2967 Residue Managers (www.yetterco.com).
Kunde is still evaluating 20" rows. "I think we're getting some yield advantage," he explains. "You get a faster canopy for weed control, and the Revised Universal Soil Loss Equation shows an improvement in soil erosion control. But you can't really avoid planting in a tractor wheel track, so there could be some compaction. Spraying is easier in 30" rows."
On D slopes, Kunde's tillage system meets the requirements for conservation compliance. If you farm fields with steeper slopes, there are additional conservation practices that might be needed, says Lori Schnoor, Kunde's Natural Resources Conservation Service (NRCS) district conservationist. (Kunde has also installed additional conservation practices, such as contour buffer strips on some of his steeper land, she notes.)
- Early Spring 2009