Dennis Redington gets up to 30 bu/acre more corn in 15" rows than in 30" rows on his poorer-quality, hilly ground. But he says the narrow rows would pay off even if they didn't increase yields because of how they hold soil and reduce erosion.

Besides the yield and conservation benefits of narrow rows, there are other advantages as well, say Redington and other farmers who have compressed their spacings.

In 1997, Redington switched to 15" rows on the ground he farms near Galena, IL. At that time, he edged up planting population from 32,000 to 34,000 seeds/acre.

Redington farms both bottom ground and hills. His rolling ground averages 4-5% slope, with peaks of 15%. He no-tills corn on the hills.

“On 1,000 total acres of corn, we average about 15 bu/acre more yield in 15" rows than in 30" rows across all terrains,” he notes. “However, it's considerably more on the hillsides than on the level ground. We were getting 120-130 bu/acre on the hills in 30" rows, but we now get up to 160 bu/acre in 15s. With our best level fields we went from about 180 bu/acre to 185.

“Even though those are not side-by-side comparisons, there's no doubt we've had a significant yield gain from the 15s,” he says.

Narrowed rows intercept more sunlight, which enhances photosynthesis. And the more evenly distributed foliage in 15" rows does a better job of deflecting raindrops before they hit the ground during heavy downpours, Redington points out. That helps reduce erosion.

Redington, who runs a cow-calf operation, hires custom operators to chop his corn silage. “They like the 15" rows because they can go either direction,” he says.

Jeff Williams and his brother, Brad, Broadhead, WI, have been in 20" rows since 1997. “If starting over again, we would go to 15",” says Jeff Williams.

The brothers, who are on rolling ground, farm on the contour. They built their own narrow-row head using plans from farmer-inventor Marion Calmer, Alpha, IL.

“According to our yield monitor, we gained 15 bu/acre or more in yield by going from 38" to 20" rows,” Willliams notes. But the soil savings, from a combination of no-till and the narrow rows, has been even more remarkable.

“We've had some extremely heavy rains in this area,” says Williams. “On neighboring farms that are in conventional rows and have been fall-chiseled and then worked in the spring, there's been so much erosion it's filled the roadside ditches with mud. In contrast, all we've had was some movement of residue.”

The Williamses rent ground from 15 different landlords in parcels of 30-110 acres. “Some of the landowners are from the Chicago area and are very conservation-conscious,” says Williams. “They have complimented us on our stewardship. Two of them brought us fruit baskets at Christmas to show their appreciation.”

There's another bonus from the narrow rows. Because of the faster canopy, the Williamses have cut their herbicide rates in half without sacrificing weed control.

Jim Rohlf has some healthy slopes in his Bennett, IA, operation. They run up to 12% in places. Although he switched to 15" rows primarily for extra yield, he also wanted to enhance soil conservation.

“I just figured narrow rows had to help control erosion,” he notes. “We went to 15" corn and 15" soybeans. With the equidistant 15" corn rows, you can plant either up and down or across the slopes and still hold the soil.”

Rohlf no-tills his soybeans and makes a light field cultivator pass to loosen and warm the soil prior to planting corn. “There's still plenty of residue after we plant corn, including some from the corn crop of two years before,” he points out.

Soil saving has been one of the rewards of narrow-row corn for Calmer, the Illinois farmer who developed the narrow-row corn head.

“In 30" rows on our rolling ground,” says Calmer, “I would see erosion between the rows during and after the growing season. Then when I no-tilled soybeans the following spring, it was hard on the equipment. Also, the bean seed would just fall into the eroded trench and never grow. The next spring we had to use some kind of leveling device to smooth the ground.”

Calmer points out that in 15" corn rows he has plants spaced 15 × 15", with roots exploring much of the soil area. That helps pick up nutrients and holds soil.

In Monroe County, WI, ag agent Jim Leverich has conducted multi-year testing of 20" vs. 30" rows. Grain yields have averaged 15 bu/acre (5-8%) higher and dry matter silage yields have averaged 1.4 tons/acre (10-15%) greater in the 20" spacings. That was at the same population for both widths.

“Besides higher yields, we have observed stronger weed control with the narrower rows,” says Leverich. “The difference comes after corn is knee high. There is more overlap of leaves between rows for shading and less, though sufficient, overlap within the rows.”

He says the Natural Resources Conservation Service (NRCS) personnel in his county like what they see in the erosion-control virtues of the narrower rows.

Mark Maidak is a University of Illinois extension adviser in the rolling terrain of northwestern Illinois. He points out that narrow-row fields harvested for grain generally have a more uniform distribution of residue than do conventional 30" rows. That helps minimize erosion.