SITE-SPECIFIC NUTRIENT MANAGEMENT FOR MAIZE HYBRIDS IN AN INCEPTISOL OF WEST BENGAL, INDIA

The area under hybrid maize cultivation is increasing rapidly across South Asia. However, information regarding the proper nutrient management for modern stay-green maize hybrids in India is not adequate resulting in low productivity. Existing nutrient management practices are not able to capture the momentum change in the scenario of soil nutrient supply capacity and plant nutrient demand for achieving higher yield target. The present study aims at establishing the site-specific nutrient management (SSNM) package for an inceptisol (West Bengal, India). Soil indigenous nutrient supply capacity and nutrient use efficiency was also evaluated by using the nutrient omission plot technique. The experiment was laid out in strip-plot design, assigning three maize hybrids (P 3522, P 3396 and Rajkumar) in the vertical strip and nine fertilizer treatments [50% RDF/Recommended dose of fertilizer, 75% RDF 100% RDF (200-60-60 kg N-P2O5-K2O ha(-1)), 125% RDF, 150% RDF, 100% PK, 100% NK, 100% NP and control (zero-NPK)] in the horizontal strip, with three replications. Results of the experiment revealed that the differences among cultivars were generally non-significant. The maize hybrids showed greater yield response to fertilization with N (4.14 Mg ha(-1)) during winter, followed by K (2.54 Mg ha(-1)) and P (1.58 Mg ha(-1)). Indigenous nutrient supply was estimated 107.2, 37.6 and 107.7 kg hat for N, P and K, respectively. Both average agronomic efficiency (AE) and recovery efficiency (RE) were increased with 50% RDF and it decreased with further increase in NPK levels up to 150% RDE The average internal efficiency (IE) was higher with 50% RDF closely followed by the treatment with absence of N. As grain yields and gross return over fertilizer (GRF) under 75 to 150% NPK treatments were similar, nutrient doses of 150 kg N, 45 kg P2O5 and 45 kg K2O ha(-1) were recommended as optimum for maize hybrids.