Effect of tillage and weed-management options on productivity, energy-use efficiency and economics of soybean (Glycine max)

A field experiment was conducted during the rainy season of 2008 at New Delhi, to evaluate the effect of tillage and weed management on productivity, energy relations and economics of soybean [Glycine max (L.) Merril]. The maximum grain yield of soybean (2.3 t/ha) was recorded in conventional tillage raised-bed. Among weedmanagement treatments, the maximum grain yield of 2.2 t/ha was recorded with treatment involving pendimethalin + 1 hand-weeding (HW). Weed-management treatments significantly influenced the energy relations in soybean crop. The highest energy output (99.2 × 10³ MJ/ha) was recorded in conventional tillage (CT) raised bed, which was closely followed by CT flat-bed (97.6 × 10³ MJ/ha). The highest energy output of 105.5 × 10³ MJ/ha was obtained under weed-free treatment, while the lowest output was obtained in the control (83.6 × 10³ MJ/ha). There was 26.2% higher energy output owing to control of weeds. The maximum net returns of 30,614 was obtained under conventional tillage raised-bed planting, closely followed by zero tillage raised-bed ( 29,674). Application of pendimethalin + 1 HW was found more remunerative with net returns of 28,019/ha, followed by application of only pendimethalin ( 27,840). Energy requirement in conventional tillage was 31.3% higher than the zero tillage flat-bed. Net energy output was the maximum in conventional tillage raised-bed, while maximum energy-use efficiency was obtained on zero tillage raised-bed system of planting.