Have you thought about your soybean seeding rate?

Maximum light interception is one of the goals achieved through optimum plant population. Early planting dates, longer relative maturities, and increased seeding density all contribute to closing the crop canopy as early as possible. Keep in mind the potential benefits and drawbacks that population can have on weed competition, white mold, and lodging.


Research done by Seth Naeve, Extension Soybean Agronomist and Associate Professor of Agronomy and Plant Genetics at the University of Minnesota showed that 75,000 plants per acre in the Southern U.S. and 125,000 plants per acre in the Northern U.S. produced near maximum yield potential. Yield will continue to increase about 1 bushel per acre with each additional 50,000 plants per acre. When seed cost is factored in you can see that you quickly lose profit when chasing additional yield.


Results from Prairie Brand’s own Precision Agronomy program at a location in North Central Iowa showed the highest yield potential was achieved at 160,000 seeds/acre. However, when factoring in seed cost 115,000 seeds/acre was the most profitable seeding rate.


I encourage you to do your own population trials. This task if much easier if you have equipment that allows you to adjust population on the go. Your equipment and management style can influence the economics differently so take the time to fine tune your seeding rate.


Summary of Various Extension Publications:

Iowa State University
125,000 to 140,000 – All row widths
University of Minnesota
Group 2 140,000
Group 1 150,000
Group 0 160,000
Group 00 170,000
30″ Rows 104,000
20″ Rows 130,000
10″ Rows 144,000
North Dakota State University – Carrington
Plant Date May 23 June 5
Population bu/ac bu/ac
200,000 66.8 55.6
170,000 66.8 54.8
140,000 66.4 53.3
110,000 64.7 49.8
80,000 57.6 42.6