Evaluation of Narrow Row Irrigated Soybean in Mississippi.

The majority of irrigated soybean in Mississippi are planted on raised beds spaced 100 cm apart, in either single or twin row arrangements. Recently, there has been interest in growing soybean in narrow rows (50 cm) on wide raised beds. Previous research indicates that narrow row spacing can provide advantages over wider arrangements, including increased light interception, improved weed management and greater seed yield. The purpose of this study was to compare soybean growth and seed yield for multiple row-spacing and seeding rate combinations for furrow irrigated soybean production in Mississippi. Field scale studies were established at three locations in the Mississippi Delta. At each location, soybean were planted in 100 cm single rows, 100 cm twin rows and 50 cm rows on wide (200 cm) beds at seeding rates of 245,000, 345,000 and 445,000 seed ha^-1. Canopy closure was monitored throughout the growing season and seed yield was determined at harvest. Soybean planted in narrow rows had consistently faster canopy closure than single rows, resulting in 11 and 13% seed yield advantage for the narrow row spacing over the single row spacing at both locations.