The evaluation of planter downforce on emergence and grain yield in soybean

Planter downforce could unify crop emergence by maintaining uniform seeding depth while planting. This research was conducted to determine if planter downforce rate impacted soybean [Glycine max (L.) Merr.] emergence and grain yield in South Carolina. The effects of tillage type, gauge wheel width, and downforce rate (0-300 lbf in 50-lbf increments) on soybean were evaluated at the Edisto (EREC) and Piedmont (PREC) Research and Education Centers in South Carolina. At EREC, a downforce rate over 200 lbf resulted in decreased plant emergence compared with 0, 50, 100, and 150 lbf. A downforce rate of 0 and 50 lbf had a reduced number of emerged plants at 2, 3, and 4 d after emergence compared with rates over 150 lbf at PREC. As downforce rate increased, the depth at which seed were planted increased up to 35% of the original planting depth at EREC. Planter downforce rate appears to influence overall soybean emergence. However, uniform emergence in soybean does not appear to impact grain yield in these production scenarios in South Carolina.