Effect of tillage and nutrient management on sorghum (Sorghum bicolor) productivity in Alfisols of semi-arid tropical India

The combined effects of tillage intensity (conventional-CT, reduced-RT or no tillage-NT) and nutrient management (inorganic and/or organic) on sorghum [Sorghum bicolor (L.) Moench] production, soil properties, weed dynamics, energy use, and economics were studied on an Alfisols in Hyderabad, India for 3 years (2011-2013). Results revealed that conventional tillage significantly increased growth parameters, viz. leaf area index, SPAD, and plant height as compared to NT, and produced 14% higher grain yield (2.94 Mg/ha) when compared to RT (2.57 Mg/ha) and 58% to NT (1.86 Mg/ha) system. No tillage significantly increased the density of grassy weed Brachiaria reptans (34.50/ m2) as compared to RT (21.83/m2) and CT (26.33/m2). However, the density of Cyperus iria (78.67/m2) and Digera arvensis (17.0/m2) increased significantly in CT. Conventional tillage significantly increased soil moisture content and Azotobacter population at 0-15 cm soil depth compared to NT conditions. Conventional tillage and application of RDF (80:40:40 kg NPK/ha) recorded maximum yield, net returns, B:C ratio and energy productivity.