Effect of integrated nutrient management on yield and nutrient uptake of rice (Oryza sativa)-wheat (Triticum aestivum) cropping system in lowlands of eastern Uttar Pradesh

A field experiment was conducted during 1999-2002 at Crop Research Station, Ghaghraghat, Bahraich to study the effect of integrated nutrient supply on yield, yield attributes, nutrient uptake and economics of rice (Oryza sativa L.)-wheat [Triticum aestivum (L.) emend. Fiori & Paol.] cropping system and soil fertility. Application of 25% recommended dose of N (RDN) through pressmud and the rest 75% NPK through inorganic fertilizers to both crops increased the grain yield of rice and wheat by 51 .I and 56.2% rsspectively over no NPK treatment. Addition of zinc with 100% of recommended NPK through inorganic fertilizers gave higher grain and straw yields of both rice and wheat over 100% of recommended NPK alone. The rice-equivalent yield and total uptake of N, P and K by rice-wheat system were highest with 25% RDN through pressmud + 75% RDF through inorganic fertil- izers, followed by 50% RDN through pressmud + 50% RDN through inorganic fertilizers. The net income and benefit : cost ratios were also highest with 25% of recommended N through pressmud and the rest 75% NPK through inorganic fertilizer. The content of organic carbon and available phosphorus in soil improved in all inte- grated nutrient-management practices than its initial soil status. The value of potassium, bulk density, pH and electrical conductivity decreased in all the integrated nutrient-management practices compared with its initial soil status.