Oren and Tom Stahl, Freeman, S.D., are experimenting with twin row corn.
"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. Our corn plants were significantly healthier when we used the twin-row system. They were greener and had improved standability. "
Twin-row planting gives plants more room to grow when population levels are at 28,000 ppa and higher. 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 inches 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" 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."
Sorensen is from Yankton, S.D.