Effect of crop residue and nitrogen levels in yield and yield attributing traits of rice under Rice-Wheat Cropping System

A 3- years (2015, 2016 and 2017) field study was carried out at National Wheat Research Program, Bhirahawa, Rupandehi, Nepal to evaluate the influence of crop residues and nitrogen levels on rice. The experiment was conducted in split plot design with three replications. Main plots were two crop residue levels (with crop residues of 30 cm wheat stubble and without crop residues) and sub plots consisted of seven nitrogen levels (0, 25, 50, 75, 100, 125 and 150 kg N ha-1). Combined analysis of three years data revealed that crop residue levels did not differ significantly in terms of grain yield; however crop residues incorporation increased the rice grain yield slightly. Significant difference was observed with application of different nitrogen levels in grain yield and yield attributing characters viz; tillers m-2, panicle length, number of filled grains per panicle and thousands grain weight. Rice grain yield was found at increasing rate with increased level of nitrogen @ 150 kg ha-1. Application of nitrogen @ 150 kg ha-1 gave highest grain yield of 4831kg ha-1 which was found at par with nitrogen @ 125 kg ha-1 with grain yield of 4722 kg ha-1. Crop residues with nitrogen @ 125 kg ha-1 resulted in 216 kg ha-1 higher rice grain yield than residues removed treatment. The overall conclusion is that an improved crop residue management with 125 kg N ha-1 increases the grain yield of rice in long run.