Row Spacing, Plant Populations, and Cultivar Effects on Soybean Production Along the Texas Gulf Coast

Three soybean ( Glycine max L.) cultivars were compared when planted in twin rows (two rows spaced 4 to 6 inches apart on a single bed with 38‐inch centers) to soybean produced in single rows on a bed (spaced 38 inches apart) at three seeding rates of 6, 10, and 15 seeds/planted ft at two locations along the Texas Gulf Coast in 2003 and 2004. Soybean yield averaged over cultivars and seeding rates resulted in the twin‐row system out‐producing the single‐row system at two of the four site‐years. Soybean yield did not increase as the seeding rate increased with either row spacing. When only seed costs were considered, the twin‐row system planted at 6 seeds/ft had the highest net return at three of the four site‐years.