Indian Journal of Agronomy

A permanent plot experiment on integrated nutrient supply system with 12 treatments replicated thrice in rice (Oryza sativa L.)-rice cropping system was conducted during 1983–84 to 2013–14 at Chiplima in a sandy loam soil. The soil had pH 5.4 and organic carbon 0.62%. Application of 50% recommended dose of nutrients through chemical fertilizers (RDF, i.e. N: P: K @ 100-22-41.3 kg/ha) coupled with 50% recommended N through green manuring of Sesbania cannabina to the rainy season (kharif) rice followed by supply of 100% RDF through chemical fertilizers to summer rice resulted in higher average (of 31 years) system yield of 9.32 t/ha/year. This treatment combination increased average system yield by 7, 25 and 122% over application of RDF, farmers' practice (N: P: K @ 50-11-20.7 kg/ha + 2 t FYM/ha for both crops) and control (without application of any fertilizer) respectively. This treatment also recorded the highest system gross returns (115, 030/ha), net returns (59, 284/ha) and benefit: cost ratio (2.06). Application of 50% RDF through fertilizers coupled with 50% recommended N through FYM to kharif rice followed by supply of 100% RDF through chemical fertilizers to summer rice was the second best treatment combination with system grain yield 9.21 t/ha/year, system gross returns (113, 520) and net returns (54, 874/ha). These were also most sustainable and improved soil physico-chemical properties with respect to bulk density, soil organic carbon, available NPK, microbial biomass carbon and soil nutrient balance.