Growth and Yield of Rice-Wheat Cropping System under different Water Regimes and Nitrogen Levels

A field experiment was conducted for two years at Experimental Farm of IARI, New Delhi to study the effect of water regimes and nitrogen levels on growth and yield of rice-wheat cropping system in a sandy clay loam soil. Pooled analysis of yield over the years showed that continuous and intermittent flooding produced statistically at par grain yield of rice which was significantly higher (23.6% and 19.3%) as compared to alternate wetting and drying. Each successive dose of 60kg/ha N resulted in significantly higher plant height, tillers/hill, number of grains/panicle, panicle length and 1000-grain weight during both the years. Residual effect of nitrogen on the plant height and number of grains per ear of succeeding wheat crop was found significant with each successive dose of N up to 120 kg/ha applied in the preceding rice. Significantly higher grain yield of rice, 14.0% and 21.6% respectively over control was realized with each successive dose of N fertilization. Each successive dose of N fertilizer applied to wheat significantly increased the wheat grain yield by 16.3% and 23.0% as compared to control over the years. Direct effect of N application to wheat was more pronounced over residual effect. Alternate wetting and drying, and intermittent flooding produced at par grain yield of rice-wheat cropping system. The results revealed that productivity of rice-wheat system is more in case of shallow submergence. However, in case of water shortage one could go for alternate wetting and drying to save water over shallow submergence and intermittent flooding.