Scott and Noel Rahn, Bingham Lake, Minn., have planted corn in 22-in. rows for 13 years. The corn and soybean growers say narrow rows capitalize on the northern Corn Belt’s long days, shade out weeds faster and make the most of today’s advanced corn genetics. Narrow rows also give them better control of in-row seed spacing, they say.

“In the northern Corn Belt, there are more daylight hours in summer, and the more sunlight you can intercept, the more carbohydrates and yield you can produce,”says Scott Rahn. As he sees it, “Any time sunlight reaches the soil, that’s wasted energy.”

Narrower rows canopy early, which “helps control weeds and also conserves moisture,”he says. And with Roundup Ready crops, “there’s no need to row-crop cultivate, which is more difficult in narrow rows.”

The Rahns plant 36,000 to 38,000 seeds/acre, aiming for ear counts of 33,000/acre. With 22-in. rows instead of 30-in. rows, the seed meter runs more slowly, “so we feel seed spacing is more accurate.”

One of the drawbacks of 22-in. rows is higher equipment cost. Narrow-row corn tends to grow taller, “so there’s more residue to manage.”The dense canopy also makes the crop more susceptible to plant diseases, Rahn adds, so a foliar fungicide application is part of their regular corn management plan.

Pioneer studies of narrow-row corn over 13 years have found considerable variation in corn yield responses to 22-in. rows, says Steven Butzen, Pioneer research agronomist. The same is true of university narrow-row studies, he says. Positive responses to the practice are most likely north of the 43rd parallel, which runs through Madison, Wis., Mason City, Iowa, and Yankton, S.D. Yield increases in the northwestern Corn Belt have averaged 4%, Butzen says. But in the central and southern Corn Belt, yield responses have been inconsistent and sometimes negative for rows narrower than 30 in., Butzen says.