Twin-row planting captures more sunlight for corn

Twin-row corn planting is hardly a new concept, but there’s new interest in the practice. Research has indicated that twin rows may take yields to the next level.

Brothers Oren and Tom Stahl, who farm southwest of Freeman, S.D., are very pleased with twin rows.

“We knew sunlight utilization increases greatly for corn plants in a twin-row system,” Oren says. “We saw both improved yield and healthier plants with 28,000 plants per acre. Researchers say that in 30-inch rows, knee-high corn captures only 30% of available sunlight. In 20-inch corn, knee-high plants capture 68% of sunlight. In twin-row corn, knee-high plants can use 90% of the sunlight.

Key Points

• South Dakota brothers are quite pleased with their twin-row corn.

• The twin-row configuration increased yields on their farm.

• Corn plants were healthier and had bigger stalks in twin rows.

“Our corn plants were significantly healthier when we used the twin-row system. They were greener and had improved standability.”

Part of the increased potential of a twin-row system centers around the fact that twin-row planting gives plants more room to grow when population levels are at 28,000 ppa and higher. In twin-row planting, corn and soybeans are planted in rows spaced between 7 and 8 inches apart on 30-inch centers.

Research has documented that root mass in a twin-row system is significantly larger than in a 30-inch system. Corn plant studies have long confirmed that as soon as a corn plant begins to touch a neighboring plant, the root system ceases to grow larger, limiting the plant’s ability to take up nutrients and moisture.

Records of stalk diameters of the same corn hybrids in twin-row and single-row configurations seem to bear out the fact that twin-row corn plants are healthier and more vigorous. Some studies reported stalk diameters in twin-row systems as large as 1.125 inches in comparison to 0.875 inch produced in 30-inch single-row plantings.

Twin-row planting also uses a significantly larger percentage of each acre because twin-row splits the population of one “single” row into two staggered twin-rows spaced 8 inches apart. At 38,000 ppa, the area of an acre used for root growth and moisture/nutrient gathering is expanded from 14.4 in a single 30-inch row to 44.5% in a twin-row system.

Not everyone agrees with the twin-row planting concept. However, even on dryland acres, the Stahls believe their crops had an advantage under a twin-row system.

“The 2011 growing season conditions were very good for us,” Oren says. “We were blessed with timely rains and all-around good growing weather. But even though we haven’t had enough rain to produce a corn crop on our dryland in 2012, I wouldn’t be surprised to see farmers with irrigated acres benefit this year from using a twin-row system.”

On average, the Stahls see between 17 inches and 18 inches of rain each growing season. Their soil types tend to be sandy, with a mix of Prosper-Clarno loams; Prosper-Stickney, Prosper and Crossplain and Dudley-Stickney complex. They also find Tetonka silty clay loam and Ethan-Betts loams in their fields. Their planter is a Great Plains Yield Pro 1625, a 40-foot, 16-row planter. They use several DuPont Pioneer hybrids.

The Stahls were considering purchasing a 20-inch single-row planter when they began exploring the advantages of twin-row planting.

“We found we could switch to twin-row and still use our existing combining equipment,” Oren says. “We stayed with the same corn hybrids we’ve been using. Those numbers vary from field to field. With the twin-row planting ,we also saw the corn plants canopy sooner, which means better moisture conservation. I had a personal best yield record in a corn growers’ contest.

“I can’t think of any disadvantages to the twin-row system,” Oren adds. “We’ll continue working with it to improve our yield.”

Sorensen is from Yankton, S.D.

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SEEING DOUBLE: Brothers Oren (left) and Tom Stahl used a twin-row planting planter for both their corn and soybeans in 2011 and 2012. Their 2011 yield increased significantly due to twin-row planting. In 2012, their corn crop dried out because of the drought, and their soybean crop was stunted due to hot dry conditions that persisted into July.

This article published in the January, 2013 edition of DAKOTA FARMER.

All rights reserved. Copyright Farm Progress Cos. 2013.