Effects of Farmyard Manure and Nitrogen Fertilizers on Yield and Yield Components of Low Land Rice (Oryza sativa L.) on Vertisols of Fogera District, Northwestern Ethiopia

Rice (Oryza sativa L.) is a major cereal crop in Fogera district; however, the current yield is decreased due to low soil fertility status as a result of continuous cultivation, inadequate use of organic and inorganic fertilizers. Hence, a field experiment was conducted at Fogera National Rice Research and Training Center (FNRRTC) during the 2021 cropping season to determine the effects of farmyard manure and nitrogen fertilizer on yield and yield components of lowland rice on vertisols of Fogera district. The treatments were laid out as factorial combination of three levels of FYM (0, 5, and 7.5 t ha-1) and four levels of Nitrogen (0, 46, 92, and 184 kg ha-1). The experiment was arranged at (RCBD) with three replications. The phenological, yield and yield components of rice data were collected during the growth period. All collected phenological, yield and yield components of rice data were analyzed by using SAS software (version 9.4). Analysis of the results revealed that application of FYM at 7.5 t ha-1 combined with 92 kg N ha-1 increased grain yield by 218.25% compared to the negative controls. The highest rice grain yield (7533.1 kg ha-1), biomass yield (14553.1kg ha-1), number of grains per panicle (153.27) and harvest index (51.89%) were obtained from the application of 7.5 t ha-1 FYM with 92 kg ha-1 N. Therefore, combined applications of 7.5 t ha-1 FYM with 92 kg ha-1 N is the recommended treatment that economically feasible for rice production and soil fertility improvements on the Vertisols of the study area, which provided the net benefit of (166,838.02ETB ha-1) with an acceptable MRR of 3122.99%.