After six years, Lance Hansen, who farms with his son Nick near Guthrie Center, Iowa, believes switching to 20" corn was a sound move for their operation. "We conducted one side-by-side comparison in a test plot put out by my nephew, and we saw some yield increase,” he says. "I think we're seeing a little higher yield in our fields, too.
"But yield was not our entire justification for going to 20" rows,” Hansen says. "We had several other reasons.”
|In addition to a potential yield increase, 20" corn rows provide a faster canopy and let Iowa farmer Lance Hansen spray contoured rows on sloping fields from any direction.
Some of those reasons are related to the highly erodible land the Hansens farm, using continuous no-till and planting on the contour. "Trying to follow a contoured row on small steep fields when spraying herbicides is a real chore,” Hansen says. "With 20" rows, we can spray any direction.
"Also, narrow rows provide a faster canopy, which helps with weed control. And if corn goes down at harvest, if you can just get the combine snout under it, it's amazing how much corn you can pick up.”
The Hansens plant 32,000 to 34,000 seeds per acre, about the same as they did in 30" rows. They use a 24-row Kinze 3700 planter equipped with Schlagel Posi-Close closing wheels for corn and soybeans. "I like 20" rows for soybeans because you get most of the yield benefit of narrow rows but more air circulation to aid in disease control,” Hansen says.
Dealing with residue from a 165-bu. to 170-bu.-per-acre corn crop—a typical yield in the Hansens' area—when no-tilling into 20" corn rows was challenging at first. "Any trash whipper will work in 30" rows,” Hansen says. "But in 20" rows, some of them throw residue against each other and plug up.” The Hansens' planter is now equipped with Yetter Ultra Narrow Titan coulter and residue manager units.
Start at harvest.
Residue management starts with the combine. The Hansens use a John Deere narrow-row corn head with knife rolls but without the optional stalk-chopping attachment. Their combine came with a high-capacity stalk chopper.
Especially with no-till, spreading residue evenly across the width of the combine header is important to get uniform emergence the following spring. That is likely to become an issue with soybean chaff.
"Our combine does a good job of spreading the residue,” Hansen notes. He uses a John Deere 9670 STS with PowerCast spreading system, a 12-row corn head and a 35' bean platform.
The advent of Bt insect-resistant hybrids does not seem to have made residue management any more difficult, Hansen observes, even though the hybrids might be expected to decay more slowly. He has noticed cornstalks get cut more effectively by the header if there's warm, dry weather at harvest.
|For More Information
|To learn more about the products mentioned in this story, visit:
Schlagel Posi-Close planter closing wheels, www.schlagel.net
Yetter Ultra Narrow Titan coulter and residue manager units, www.yetterco.com
To download a copy of a 20-page booklet about how continuous no-till improves soil quality, go online to www.ctic.purdue.edu. Click on "CTIC Publications,” then click on "Better Soil, Better Yields.”
"If there's a downfall to 20" rows, it's the difficulty of combining them on the contour,” Hansen concludes. "A 20" corn head costs more, but a 20" planter is no more expensive than a split-row machine. All in all, 20" rows offer a potential yield increase for a relatively small investment.”
You can e-mail Darrell Smith at
- December 2008