Integrated nutrient management in spring-maize improves yield, nutrient use efficiency and minimizes greenhouse gas intensity

Ensuring food security and simultaneously maintaining environmental integrity has become a major challenge in modern agriculture. Quantification of trade-offs between productivity, fertilizer use and greenhouse gas (GHG) emissions in agriculture is important for the development of management strategies to ensure food security and environmental sustainability. The present study investigated the effect of synthetic fertilizer (SF) versus SF plus farmyard manure (FYM) in various combinations on soil fertility, grain yield and agronomic efficiency (AE) and GHG intensity (GHGI) in spring-maize for four years. A combination of 100% of the recommended NPK along with FYM (100%NPK+FYM) resulted in maximum (20-24%) increase in soil organic C content over 100%NPK alone treatment. Similarly, 100%NPK+FYM increased soil available N, P and K by 20, 73 and 33% over 100%NPK treatment. Continuous use of integrated nutrient management (INM) practices had a favourable impact on spring-maize grain yield, maximum being in 100%NPK+FYM (8.09 t ha(-1)) and 125%NPK+FYM (8.16 t ha(-1)) treatments. Though the grain yield between 100%NPK+FYM and 125%NPK+FYM treatments was similar, maximum AE of N, P and K and minimal GHGI was achieved in 100%NPK+FYM treatment. The results of the study indicated that application of 100%NPK+FYM in spring-maize proved to be agricultural and environmental sustainable management practice.