Green manuring, mustard residue recycling and fertilizer application affects productivity and sustainability of Indian mustard (Brassica juncea L.) in Indian semi-arid tropics

An experiment was conducted for five-years (2005-06 to 2009-10) to evaluate the impact of Sesbania green-manuring (GM), mustard-residue recycling and fertilizers on soil health and productivity of Indian mustard under fallow-mustard sequence. Sesbania (GM) significantly increased SOC, carbon-sequestration-potential rate, infiltration rate, available NPK status but decreased bulk density. Supplementing mustard-residue recycling 2.5 t ha(-1) further improved the soil quality attributes significantly. The increase in fertilizer from N40P8.7K0 to N80P17.4K33.3 also improved the soil attributes gradually. This improvement in soil properties due to Sesbania (GM) and mustard-residue recycling significantly influenced plant height, branches/plant, siliquae/plant, seeds/siliqua and ultimately seed and oil yield compared to existing fallow-mustard practice. The mustard seed yield was increased by 42.3% due to Sesbania (GM) and by 63.9% due to supplementary mustard residue recycling in five years. Increase in fertilizers levels from N-40 to N-80 and P-8.7 to P-17.4 significantly improved mustard yield attributes, seed and oil yield while results of K application was inconsistent. The combined application of N80P17.4K33.3 synergistically increased the seed yield by 82.1% over N40P8.7K0. Sustainability yield index, partial factor productivity, production efficiency and incremental benefit cost ratio also showed significant improvement due to Sesbania (GM), mustard-residue recycling and judicious fertilizer use. (C) 2012 Elsevier B.V. All rights reserved.