Summary of Multi-State State Research on Soybean Row Width, Planting Date, and Plant Population

 

With funding from the United Soybean Board, soybean agronomists across the US came together to summarize soybean row width, planting date, and seeding rate research trials. (Ohio-specific research trials were funded by Ohio Soybean Council.) Here’s what we found:

 

Row width: Soybean row width varies across the US. In Ohio, most farmers plant soybean in 7.5, 15, or 30-inch row widths. Across the US, narrow rows (7 to 15 inch) out-yielded wide rows (≥ 30 inches) 69% of the time. Narrow rows tend to out-yield wide rows due to earlier canopy closure which facilitates light interception and drives photosynthesis. For the full report on row spacing: https://soybeanresearchinfo.com/wp-content/uploads/2021/02/FINAL-2700-002-20-Row-Spacing_Science-for-Success-Dec-22_v1.pdf

 

Planting date: The date of planting has more effect on soybean grain yield than any other production practice. In many instances, this means planting soybean as early as field conditions allow, but generally at or after the Risk Management Agency (RMA) replant crop insurance dates begin. In Ohio, we estimate a yield reduction of 8% when planting soybean on May 31 compared to May 1. Although, this reduction can vary (or become minimal) depending on rainfall during the R3 to R5 growth stage. For the full report on planting date: https://soybeanresearchinfo.com/wp-content/uploads/2021/02/FINAL-2700-002-20-Planting-Date_Science-for-Success_Dec-22_v3.pdf

 

Population Density: Soybean plants respond to their environment through branching and can produce maximum yields at relatively low plant densities (plants per acre). For normal planting dates in the Midwest, generally 100,000 to 125,00 plants per acre is required to achieve maximum yield. (A higher population density is needed as soybeans are planted into June and July.) For the full report on population density: https://soybeanresearchinfo.com/wp-content/uploads/2021/02/FINAL.2700-002-20-Seeding-Rate_Science-for-Success_Dec-23_v1-1.pdf

 

Interested in more? Soybean agronomists, Dr. Shawn Conley (University of Wisconsin- Madison), Dr. Seth Naeve, (University of Minnesota), and Dr. Rachel Vann (North Carolina State University) will be discussing these topics during a Planting Considerations webinar on Friday, February 19 at 12:45-1:45 PM. Click here to register: https://www.eventbrite.com/e/science-for-success-soybean-planting-considerations-tickets-140292814585?utm-medium=discovery&utm-campaign=social&utm-content=attendeeshare&aff=escb&utm-source=cp&utm-term=listing