International Journal of Advanced Biological and Biomedical Research Available online at http:www.ijabbr.com Volume 8, Issue 2 (2020) pp. 146-152 DOI: 10.33945/SAMI/IJABBR.2020.2.5 146 | Page Original Article Effect of Crop Residue and Nitrogen Level in Yield and Yield Attributing Traits of Rice under Rice-Wheat Cropping System Narayan Khatri 1, *, Nabin Rawal 2 , Devraj Chalise 3 , Mamata Bista 4 , Bisheshwor Prasad Pandey 1 1 National Wheat Research Program, Bhairahawa, Rupandehi, Nepal 2 Soil Science Division, Khumaltar, Nepal 3 National Maize Research Program, Rampur, Chitwan, Nepal 4 Regional Agriculture Research Station, Lumle, Kaski, Nepal *Corresponding Author E-mail: narayan.iaas068@gmail.com Received: 24 August 2019, Revised: 12 October 2019, Accepted: 17 October 2019 ABSTRACT A 3 years (2015, 2016 and 2017) >ield 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 residue and without crop residue) 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 the increased level of nitrogen @ 150 kg ha -1 . Application of nitrogen @ 150 kg ha -1 gave highest grain yield of 4831 kg 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 drawn from the three years field experiment was an improved crop residue management with 125 kg N ha -1 increased the grain yield of rice. Key words: Crop residue, Nitrogen levels, Rice, Yield Introduction In recent years, use of combined harvester for harvesting and threshing of rice and wheat crop has been increasing in Western Terai region of Nepal. The crop residue left over after harvesting of previous corp by using combined harvester is major concern to manage for planting succeeding crops under rice-wheat cropping system. So, farmers are compelled to