Planting Narrow-Row Soybean Leads To Increased Yield And Farm Profitability Under Conventional Tillage In The Northeast

Abstract

Growers can plant soybean [Glycine max( L.) Merr.] with a grain drill or row crop planter, which can affect seed and weed control costs and yield. Farmers planted soybean with a grain drill in 0.19 m rows and a row crop planter in 0.38 and 0.76 m rows at recommended (420,000 seeds ha1 ) and reduced (321,000 seeds ha-1) seeding rates in two field-scale studies in New York to obtain agronomic information and conduct partial budget analyses to aid growers in future planter purchase decisions. Soybean intercepted more light in 0.19 (65-70%) compared with 0.76 m rows (50-55%) at flowering, despite lower early plant establishment (~70 and ~85%, respectively) at both locations. At the no-till location, soybean in 0.76 m rows compared with narrower rows had greater weed density at full pod stage (19.7 vs. 6.3 and 5.1 plants m-2) and biomass at harvest (13.7 vs. 6.6 and 7.3 g m-2), but similar yield (~3.30 Mg ha-1). At the chisel tillage location, soybean in 0.19 m rows at 420,000 seeds ha-1 yielded more (4.27 Mg ha-1) than other row spacing by seeding rate combinations (4.15 to 4.01 Mg ha-1). Partial budget analyses indicated that soybean in 0.19 m rows at 420,000 seeds ha-1 had ~$30 ha-1 increased profit compared with 0.76 m rows at 321,000 seeds ha-1. Partial budget analyses indicated that for farms without a grain drill the 4% yield advantage offsets costs of purchasing and owning a grain drill and added seed costs at present market and seed price.