Using the same hybrid and fertility program, Allen Decker found 15" rows outyielded 30" rows by 7 bu. to 20 bu. per acre.
If growing corn was like horse racing, the announcer on Allen Decker’s farm would sound like this: "They’re through August, they’re past September, they’re heading for the finish line … and the winner is 15" rows, with 30" rows in second!"
Farming isn’t much like horse racing, though it may seem like a gamble at times. But there is one parallel: As with thoroughbreds, Decker’s 15" rows will remain champion only until a challenger beats them, if one ever does.
The Wellington, Ill., corn and soybean grower has compared 15" and 30" rows side by side—same hybrid, same fertility program—on his various soil types for three years. In 2010, he planted half his acres to each row width, using 15" and 30" planters.
"There has been a 7-bu.- to 20-bu.-per-acre advantage for narrow rows every year," he says. "I think we’ll plant all narrow-row corn this year. However, we might plant in 20" rows, rather than 15", so we can sidedress fertilizer."
Gearing up for 2009’s test took a little engineering. "The planter we had been using for 15" rows didn’t have room for fertilizer attachments," says Derric Eisenmann, who works with Decker. "The corn seemed to run out of nutrients late in the season, so we needed to apply more nitrogen. The 15" rows are too narrow to sidedress, so planting time is our only chance to get fertilizer right."
Modified right. Great Plains Manufacturing offered the only planter with room for fertilizer coulters in 15" rows, Decker says. His dealer’s planters were set up for twin rows, so he and Eisenmann modified a 60' model to plant 15" rows. They left 30" spacing behind the tractor’s dual tires and one 30" row in the middle for Decker’s sprayer to follow. Martin row cleaners sweep clods and residue away from the planting units.
Decker applies a 28% urea-ammonium nitrate (UAN) solution through Yetter Manufacturing 2995 Series fertilizer coulters. Each coulter feeds two rows of corn, and each row has a Wilger monitor.
The UAN solution is metered by a hydraulically driven diaphragm pump from SureFire Ag Systems.
"Hydraulic control lets us vary the rate of nitrogen," Eisenmann says. "We apply from 20 gal. to 60 gal. per acre, depending on the hybrid and the field. We control the fertilizer with a John Deere monitor and rate controller."
A pull-behind Great Plains cart carries 1,600 gal. of UAN solution. Two 200-gal. tanks mounted on the planter carry starter fertilizer.
Decker harvests 15" rows with a 24-row head built by Clarke Machine. It’s possible to harvest 15" rows two at a time, using a 30" head, he notes, but it’s tiring for the operator.
He plans to stick with 15" or 20" corn rows for now until something else yields better. "We’re testing twin rows, on a small scale using a seed company’s planter," he says.
- Mid-February 2011