Soybean (Glycine max) growth, productivity and water use under different sowing methods and seeding rates in Punjab

A field experiment was conducted from 2006 to 2008 to study the effect of four sowing methods namely raised bed planting (67.5 cm wide, 2 rows per bed), raised broad bed planting (135 cm wide, 4 rows per bed), ridge-furrow sowing (60 cm spacing) and flat sowing (45 cm spacing) and three seeding rates i.e. 50, 62.5 and 75 kg/ha in soybean [Glycine max (L.) Merrill]. The highest photosynthetically active radiation interception (PARI) and net returns were recorded in raised bed planting. The highest seed yields was recorded in raised bed sowing, which was 6.70 and 5.29% higher than ridge-furrow and flat sowing methods, respectively. The highest water productivity was recorded in raised broad bed sowing which was significantly higher than flat sowing and ridge-furrow sowing methods but statistically on par with raised bed sowing. Seed rate of 50 kg/ha recorded highest crop growth rate (CGR) and pods per plant whereas the highest PARI was observed with 75 kg/ha seed rate, which was statistically on par with 62.5 kg/ha seed rate but significantly higher than 50 kg seed/ha. The soybean productivity and net returns were highest with 62.5 kg/ha seed rate.