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No-till soybeans this spring

Farmers attending Iowa State University’s Crop Advantage meetings around the state this winter harvested information on a number of topics. One was no-till soybeans; why more farmers should be switching to no-till beans. No-till corn can have more complications. Success comes easier with no-till beans, and they save time and money — two things farmers will run short of this spring.

Palle Pedersen, former ISU Extension soybean agronomist, points out that Iowa lags behind neighboring states in adopting no-till soybeans. Pedersen left ISU Jan. 31 to work for Syngenta.

One reason Iowa farmers don’t plant a higher percentage of the soybean acres to no-till is that beans look ragged for the first few weeks after emerging. Stands are often uneven as crop residue keeps the ground cooler compared to tilled fields. But eventually no-till beans catch up to the tilled beans once it’s warmer and the crop gets going. “You don’t want to let cosmetics overrule economics,” says Pedersen. “Soybean plants in no-till can usually overcome the slow start early in the season to produce equal or better yields in well-drained soils. Field drainage is a key factor.”

Cosmetics or economics?

Pedersen says more farmers could be planting beans no-till into corn stubble, then doing a little tillage before planting corn in a corn-bean rotation. His field trial results back up that conclusion.

Pedersen conducted a detailed, three-year study of no-till beans at six Iowa sites. The 2007-09 study shows no-till soybeans outyielded conventional tillage in four out of six sites. Averaged over the three years, the yield differences ranged from 0.4 to 1.5 bushels per acre.

Soybeans grown in conventional tillage performed better than no-till in northwest and north-central Iowa. They beat the no-till beans by 0.3 bushels per acre at Linn Grove and 1.4 bushels at Humboldt. But that wasn’t enough to pay for the tillage costs — about $12 to $18 per acre. “Your business is farming; your hobby is doing tillage,” Pedersen tells farmers. “You need to find a new hobby. Recreational tillage is expensive.”

Poorly drained soils, such as those dominating the Des Moines Lobe area stretching from central Iowa to Minnesota, can make it difficult to raise high-yielding no-till beans. But on better drained soils, growers can make no-till pay with some management changes.

Tools are now available to minimize the risk of no-till, such as seed treatments, better postemergence herbicides and improved seed genetics. No-till soils are usually wetter and a few degrees cooler in the spring compared to tilled fields. You may have to wait a few days longer to plant no-till beans.

Preparing for no-till beans starts in the fall with corn harvest, he adds. Bigger corn yields produce more crop residue. It needs to be evenly distributed in larger pieces instead of finely chopped. A mat of residue is hard to plant through.

At planting, pay attention to your settings of closing wheels, residue cleaners and planting depth. Check and adjust field by field. Floating residue cleaners worked best in the ISU study. Fixed residue cleaners were often too aggressive.

Pedersen suggests planting beans in a 15-inch row width, going the same direction as the previous year’s crop. ISU studies show a yield advantage of 3.8 bushels per acre for 15-inch compared to 30-inch rows. The highest-yielding varieties in conventional tillage were also the best performers in no-till fields. Seed treatments helped improve the stand with early planting in no-till.

“In addition to saving time and money, no-till offers other advantages, such as improved soil tilth, increased organic matter, erosion reduction and saving soil moisture for use by the crop,” he adds.

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This article published in the March, 2010 edition of WALLACES FARMER.

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