Kelly Nichols, Agriculture Agent
University of Maryland Extension, Montgomery County
Research on the effect of soybean planting population on yield was conducted for a second year. In 2019, there were two on-farm locations in Frederick County. This year, the study was expanded to include one on-farm location in Carroll County and four University research farm locations (Keedysville, Beltsville, Upper Marlboro, and Queenstown). Soybeans were planted at 80,000, 100,000, 120,000, 140,000, and 160,000 plants per acre. At the Queenstown location, a population of 50,000 plants per acre was added.
A final stand count was taken prior to harvest at all locations. While we are still summarizing and collecting data, a few observations can be made. Final stand counts indicate that similar plant loss occurred across all planted populations, most likely due to the percent germination of the seed, insects, disease, and weather. Soybeans at the lower populations were more branched and bushy compared to soybeans in the higher populations. This is not surprising, as beans are able to compensate for missing plants around them. This ability to compensate may result in comparable yields across the planted populations. In 2019, yields across all populations were within a few bushels and not statistically different. The cost of the seed will be compared to the sale of the soybeans to determine net profit per acre. For more information on the 2019 and 2020 results (once completed), visit this project’s webpage on the National Soybean Research Checkoff Database.
