Optimum N Rate for Sustainable Rice-Wheat System Under Tillage and Crop Residue Management.

Application of an optimum rate of nitrogen is very crucial to maintain the sustainability of a rice-wheat cropping system (RWS). A three-year field experiment was conducted on acid sandy loam soil to select the best N-management practice, along with tillage and crop residue (CR) incorporation for RWS. Changes in soil properties were assessed to determine the effect of tillage and crop residue application on soil fertility, loss and uptake of N, and yield of rice and wheat (RW) crops. Application of CR and intensive tillage increased the N leaching loss; however, it also increased N uptake and yield of RW crops and resulted in minimal degradation of soil environment. Overall results of loss, uptake, N-use efficiency, and yield attributes of RW crops indicated that a comparatively lower rate of N along with RW residue incorporation in combination with less intensive puddling for rice and medium-intensive tillage for wheat can be opted as sustainable management practices. Thus, the use of comparatively lower rate of N will reduce water pollution from extra leached N and reduce the cost of farming, too. On the other hand, use of RW residue will enrich the soil organic carbon pool and improve the quality of the soil. Use of less intensive tillage along with RW residue application will increase the porosity of the soil, reduce soil erosion, and help sustain the RW system. [ABSTRACT FROM AUTHOR]