Effect of irrigation and crop residue management on crop and soil productivity under soybean-sorghum cropping system

Field experiment was conducted during 1993–94 to study the effect of sugarcane trash incorporation and irrigation to soybean on crop productivity and its residual effect on succeeding crop under soybean-rabi sorghum cropping system grown on Parbhani clay soil (Vertisol). It was observed that soybean significantly responded to irrigation application at flowering and grain formation stages. Sugarcane trash incorporation with irrigation to soybean recorded significantly higher grain yield, increased water use efficiency, protein and oil contents of soybean. Sugarcane trash applied @ 5 Mg ha⁻¹ increased sorghum grain yield by 22 per cent over control. Sugarcane trash @ 5 Mg ha⁻¹ + 80 kg N, 40 kg P₂O₅ and 40 kg K₂O ha⁻¹ recorded the highest grain and fodder yields of sorghum. It also increased the concentration of N, P, K and their uptake in sorghum plant. Crop residue incorporation considerably improved the soil properties such as decreased bulk density and increased per cent water stable aggregates > 0.25 mm, infiltration rate, organic carbon, available N, P and K content in soil at the harvest of second crop in soybean-sorghum sequence.