Effect of integrated nutrient management on crop productivity and changes in soil fertility in maize (Zea mays)–wheat (Triticum aestivum) cropping sequence

The study was conducted during 2009–11 at Ranchi, Jharkhand, to study the effect of integrated nutrient management practice on system productivity and change in soil-fertility status under maize (Zea mays L.)–-wheat [Triticum aestivum (L.) emend. Fiori & Paol.] cropping sequence in the field under long-term experiment since 1983. Continuous application of organic sources farmyard manure (FYM), cut paddy straw and green karanj (Pongamia sp. leaves) along with chemical fertilizers improved grain yield and soil-fertility status. Substitution of 50% N through FYM and 50% recommended dose of fertilizer (RDF) in maize and 100% RDF through inorganic fertilizer in wheat recorded the highest system productivity (wheat-equivalent yield 8.2 t/ha), net returns (51,196.0/ha), benefit: cost ratio (0.93) and nutrient uptake (209.2, 30.4 and 196.0 kg N, P and K/ha) in maize–wheat cropping system. Soil-fertility status in terms of pH, organic carbon, available N, P, K, S and B after 28 cycles of cropping, fertilizer and manure application were also affected by nutrient-management practices. Available S was above critical level for all the treatments, while available B varied from 0.27 to 0.54 ppm after 28 cycles of cropping. Continuous cropping with combined application of organic manure along with chemical fertilizers was found to be effective not only, for increasing grain yield of crops in maize–wheat cropping system, but also, for higher benefit: cost ratio, nutrient uptake and maintenance of soil-fertility status.