Productivity and economics of rice (Oryza sativa L.)-wheat (Triticum aestivum) cropping system under integrated nutrient supply systems

A field experiment was conducted during the rainy and winter seasons of 1995-96 and 1996-97 to study the influence of integrated nutrient-supply system, comprising inorganic fertilizer and organic manures, on the soil-fertility status, productivity and economics of rice (Oryza sativa L.)-wheat (Triticum aestivum L. emend. Fiori & Paol.) cropping system. Green-manuring with prickly sesban or dhaincha [Sesbania cannabina (Retz) Pers.; syn. S. aculeata] to supplement 50% of the recommended nitrogen dose and rest through inorganic fertilizer and 100% recommended dose of fertilizer to wheat crop gave the maximum yield of rice as well as wheat crops. The same treatment also gave the highest net returns and benefit : cost ratio, and produced significantly higher biomass in terms of rice-equivalent yield. Among the organic manures, the overall performance of green-manure was best followed by farmyard manure and rice straw. The results showed a possibility of saving 50% fertilizer N in rice and 25% in wheat. Application of farmyard manure and rice straw as well as green-manuring in rice significantly improved the available N and P status of soil.