Influence of Row Width on Soybean Yield

Trial Objective

• Deciding which row width to use when planting a crop is one of the many important decisions farmers make when trying to maximize the potential yield of a production system. Thirty-inch rows are the standard row width and are typically seeded with a planter, which provides improved seed-to-soil contact and seed singulation when compared to a drill. Rows narrower than 15 inches are typically seeded with a drill. By using a drill, crop canopy closure can be achieved earlier in the growing season, providing the crop a competitive advantage over weeds. In addition, drills are not used to plant corn and are likely readily available to plant soybean during the spring.
• This trial was conducted to determine if row width impacts dryland soybean yield.

Research Site Details

• The study was set up as a split-plot with four replications. Row width was the whole plot and seeding rate was the subplot.
• A 2.4 maturity group soybean product was planted in all plots.
• Two row widths were used:

—30-inch row seeded with the planter

—7.5-inch row seeded with the drill

• Four seeding rates were used:

—120,000, 160,000, 200,000, and 240,000 seeds/acre

• Weeds were controlled as needed and no fungicide or insecticide was used on the plots.

Understanding the Results

• There was no interaction between row width and seeding rate.
• There was no significant difference in yields by row width with the 30-inch row soybean yielding 61 bu/acre and the 7.5-inch row soybean yielding 64 bu/acre when averaged across the different seeding rates.
• Seeding rate did not influence yield significantly with the 120,000, 160,000, 200,000, and 240,000 seeds/acre rates yielding 61, 60, 61, and 61 bu/acre, respectively, when averaged across row widths.

What Does This Mean for Your Farm?

• On dryland fields with moderate yield potential, row width will likely not impact soybean yield.
• If soil conditions allow for good seed-to-soil contact from soybean seeded with a drill for 7.5 inch row, soybean yield will likely be on par with 30-inch row soybean seeded with a planter.