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A wider path to narrow-row corn

Conversion kit makes it easier to build your own 15-in row units.

A few years ago, when Case Corporation bought the rights to Marion Calmer's patented universal corn-picking row unit, the self-styled narrow-row corn crusader figured 15-in. corn headers were on the fast track to wide acceptance. But then Case decided to not pursue the project. And the Renaissance farmer soon found himself looking into the manufacturing business, building narrow-row header conversion kits and selling them directly to his fellow farmers.

"I'm convinced that narrow-row corn provides a significant yield advantage over conventional 30-in. rows," Calmer says. "Equidistant spacing between plants improves light interception and yield potential while a denser canopy reduces weed control costs. The more research we do, the more we realize it isn't just a regional phenomenon confined to the northern Corn Belt. I've talked to growers in Kentucky and Texas who've posted 15% yield advantages, too." University researchers throughout the Corn Belt are now compiling narrow-row corn data from 30 farms to determine if narrow rows provided a significant yield advantage in 2000. Calmer plans to post the data on his Web site as they become available.

Narrow-row challenges. Despite the promise of higher yields, Calmer and other experienced farmers know that narrow-row corn has its challenges. A denser canopy can trap humidity and lead to disease and stalk rot problems in disease-susceptible hybrids. And although a 30-in. corn header can be used to harvest 15-in. rows, it's usually a tricky operation, requiring the driver to slow down and raise the header higher in order to avoid harvest loss. The process can be tedious, making 50 acres of 15-in. corn about all most farmers would care to harvest with a 30-in. head. Calmer says his 15-in. header conversion kit solves that problem, making it possible to harvest narrow-row corn at normal speed and perhaps even faster than in conventional rows. Calmer explains that it's easier for the combine to process one ear per foot of row in 15-in. rows versus two ears per foot of row in 30-in. rows.

Farmer-built solution. "We have orders for approximately 20 kits so far and hope to have 50 sold before 2001 harvest," Calmer says. "I've talked to several farmers who've converted old heads to narrow rows with and without the kit. The parts and instructions in our kit make the process easier than starting from scratch."

For farmers who already use a Kinze splitter planter to plant soybeans in 15-in. rows, it makes sense to adopt the same corn row width. Since making the switch four years ago, Bennett, IA, corn and soybean grower Jim Rohlf has planted all his acres with the same planter. Rohlf says the convenience, plus improved weed control and soil erosion resistance, made it worthwhile to build his own 15-in. corn head. "I think 15-in. corn performs especially well with a conservation tillage total post-applied herbicide program," Rohlf says. "The thick canopy in narrow-row corn keeps waterhemp in check for us. And the plant spacing provides a solid mat of material that holds the soil in place after harvest."

Rohlf customized his 15-in. header by blending parts from an old John Deere frame and an old International header over the winter months, then spent the summer installing a homemade prototype of the Calmer row unit kits. "We built our unit based on an experimental license from Calmer," Rohlf says. "It worked great. And if we build another head, it should be even easier with the ready-made Calmer kit."

When you build your own header, there's usually more than one way to get the job done. Calmer recommends reconditioning an old John Deere 30- or 36-in. corn header, including cluster gear, stock rolls and seals, then hiring a machine shop to grind down the sidewalls to 15 in.

Todd Schlachter of Lena, IL, used three reconditioned headers - an 8-row, a 6-row and a 4-row - to build his 16-row narrow-row unit with two spare row units. He did most of the work himself, including narrowing the gearboxes down with a torch. Schlachter estimates the entire project cost $25,000. "Cutting the gearboxes down was the hardest part," he says. "We wanted the local machine shop to do it, but they were busy, so I just fired up the cutting torch and it worked out fine."

The payoff? Schlachter says he gains an average of 22 bu./acre by going to 15-in. rows. And where high winds caused down corn this past season, his home-built narrow-row header was able to pick it up "like a fork through spaghetti."

Calmer's kit provides plastic ear guides, paddles, new deck covers, mounting hardware and an instruction manual. Cost of the kit itself is approximately $500/row. For farmers who like narrow-row corn but aren't looking for another shop project to keep them busy, Calmer says he's now building some complete headers to sell and he has a list of farmers and machine shops that will take the kit and do the header conversion work for a fee. For more information, contact Calmer Ag Research Center, Dept. FIN, 550 N. Know Rd., Alpha, IL 61413, 309/334-2609, e-mail, visit

Though not affiliated with Calmer, another source of 15-in. corn heads and kits is Clarke Machine. For more information, contact Clarke Machine, Dept. FIN, Box 694, Howard, SD 57349, 800/658-4568, www.clarke

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