Effect of Soybean Row Spacing and Plant Population on Soybean Yield.

Despite a century of research, soybean row spacing and plant population continue to be important research topics.  Changes in soybean genetics, maturity group utilization, biotechnology, production practices, planter technology, seed costs, and rotational crops may influence optimum soybean row spacing and plant population combinations.  The objective of this field research was to identify row spacing and seeding rate combinations that optimize yield and profitability of non-irrigated soybean produced in the upper mid-southern United States.  Glyphosate-resistant MG IV soybean cultivar ‘Asgrow 4303’ (relative maturity=4.3) was no-till planted on rows spaced 19, 38, 76, and 102 cm apart at seeding rates ranging from 148,000 to 543,000 seed ha^-1 at a site in western TN in 2010.  Correlations among soybean row spacings, seeding rates, final plant populations, and soybean yields were examined.  These results will help increase the efficiency and profitability of soybean production in the upper mid-southern United States.