Narrower Row Spacing Boosts Corn Yields

Planting corn in rows spaced 15 inches apart rather than the traditional 30 inches increases yields and has other benefits as well, according to Agricultural Research Service scientists who are studying the benefits of narrower row spacing.

ARS soil scientists Ardell Halvorson and Curtis Reule of the Soil-Plant-Nutrient Laboratory in Fort Collins, Colo., have found a 20 percent yield increase in the first year of a study using the narrower spacing. The researchers do not know exactly why the yield increased, but the corn may be using sunlight, water and nutrients more efficiently in the more closely spaced rows, according to Halvorson.

In addition to higher yields, farmers who plant corn in narrow rows should have fewer weeds, because increased shading from the corn plants and competition for water, sunlight and nutrients makes it tougher for weeds to survive.

Farmers who decide to plant corn in rows with 15-inch spacing will likely have to modify existing planters and combines or buy new equipment. But Halvorson says the yield advantage and weed control benefits of narrow rows may justify Great Plains farmers' buying the new equipment or modifying their existing equipment to farm on the more narrowly spaced rows.

Halvorson studied row spacing of dryland corn and sunflowers in North Dakota and found similar benefits from narrower rows. Other researchers have gotten similar results with various crops such as soybeans, and narrow rows may help backyard gardeners decrease weed competition in their gardens.

Halvorson and Reule are repeating their study this year, but the initial results are consistent with earlier research on narrow spacing of crops.

ARS is the U.S. Department of Agriculture's chief scientific research agency.