Long-term impact of integrated nutrient management on sustainable yield index of rice and soil quality under acidic inceptisol

Abstract

An in-depth knowledge on impact of integrated nutrient management (INM) practice on yield sustainability and soil quality is important to scale INM practice across regions. Therefore, field experiment was initiated in 2006, which consisted of five treatments: absolute control, 100% recommended doses of nitrogen (N), phosphorus (P) and potassium (K) (RDF), 50% recommended doses of NP + 100% K + biofertilizers, 50% recommended doses of NP + 100% K + 1 t ha−1 enriched compost (ECM) and 25% recommended doses of NP + 100% K + 2 t ha−1 ECM (25RDF + 2ECM). The use of 25RDF + 2ECM increased soil organic carbon by 32 and 24% over control and RDF, respectively, at 0–5 cm soil layer. It also increased soil microbial biomass carbon, microbial phosphorus and phenol oxidase activity by 13.7, 20.9 and 55.7% than RDF, respectively, at 0–5 cm layer. Notably, phenol oxidase activity, pH, DTPA-extractable iron, available K, mineral N and microbial biomass phosphorus came out as the key indicators of soil quality in acidic soil after 10 years. The study recommends that INM practice comprising ECM and reduced inorganic fertilizers could enhance soil quality and yield sustainability of rice in the long-run in acidic soil ecology.