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Update On Row Width Effects On Soybean, K-State-USB-Kansas Soybean Project

Apr 24, 2017
By Ignacio Ciampitti
Crop Production and Cropping Systems Specialist
 
There are still many questions about row spacing for soybean production. Our research information has found that narrow rows (15-inch or 7.5-inch) result in equal or greater yields compared to 30-inch rows when the yield environment is greater than 45-50 bushels per acre (regardless of planting date, seeding rate, or maturity). Below this yield threshold level, narrow rows tend to result in yields about equal to or slightly below (depending on the growing conditions, water status) yields in 30-inch row spacing. Narrow rows have several benefits such as early canopy cover, better light capture, improved weed control, and reduced erosion. Poor stands, however, are more common with narrow than with wider row spacing.
 
For the 2015-16 seasons, on-farm studies (a collaboration between K-State, Kansas Soybeans, and the United Soybean Board) showed about a 2-bushel yield improvement with narrow rows (15-inch), with yields averaging 48 bushels per acre (Figure 1). Narrow rows have several benefits such as early canopy cover, better light capture, improved weed control, and reduced erosion. Poor stands, however, are more common with narrow than with wider row spacing.
 
Overall Summary
 
 
Figure 1. Soybean yield, expressed in bushels per acre, for conventional (30-inch) versus narrow (15-inch) row spacings.
 
Overall, narrow rows provided a yield response ranging from -0.6 to +4.0 bu/acre at the four locations.