Effect of Organic Manures and Chemical Fertilizers on Maize Productivity and Soil Properties in the Winter Season

Field experiments were conducted at the National Maize Research Program Rampur, Chitwan, Nepal, during the two consecutive winter seasons of 2018/19 and 2019/20. The objective was to identify the effects of different sources of nutrients on the growth and yield parameters of winter maize and soil properties. The experiment was laid out in a randomized complete block design with three replications and twelve treatments. Combinations of different organic and inorganic sources, including the recommended dose of chemical fertilizer, farmyard manure, poultry manure, biochar, vermicompost, mustard oil cake, sunhemp and bone meal, were tested. Different nutrient levels significantly influenced the maize grain yield. The maximum grain yields of 7102 kg/ha (2018/19) and 6985 kg/ha (2019/20) were obtained with the combined application of 50% recommended dose (RD) of chemical fertilizer along with mustard oilcake at the rate of 5 t/ha, which was at par (6969 kg/ha and 6535 kg/ha) with the sole application of mustard oilcake at 10 t/ha. It can be concluded that the highest grain yield (7043.5 kg/ha) was obtained when 50% of the recommended dose of N, P2O5 and K2O fertilizers were combined with 5 t mustard oilcake/ha application, followed by sole application of 10 t mustard oilcake/ha (6752 kg/ha). Soil properties including organic matter were found to be significantly improved due to the application of a combined application of organic and inorganic fertilizer. Thus, in subtropical conditions, integrated organic manures and chemical fertilizers can enhance soilproperties and increase maize productivity during the winter season