Jarrod O. Miller, Extension Agronomist, jarrod@udel.edu and Cory Whaley, Sussex Co. Extension Ag Agent; whaley@udel.edu
Research was conducted on irrigated soybean seeding rates at the Warrington Research Farm in 2017 and 2018. Soybeans were planted in 15” rows at rates of 80, 100, 140, and 170 thousand seeds per acre in irrigated and dryland plots. No yield advantage was observed at higher seeding rates, while the use of irrigation improved yields by an average of 7 bu/acre over both years. With no difference in yield by seeding rate, projected income was greater at the lowest seeding rate of 80k seeds. This represents only two seasons of research on one soil type, but does indicate that Delaware soybean producers could potentially lower their seeding rates and not see a decrease in yield.
To read the full report see: https://www.researchgate.net/publication/329811290_2017-2018_Irrigated_Soybean_Seeding_Rates