Sources of nitrogen fertilizers and crop yield responses in soils of North West Ethiopia

Degradation of land and associated poor soil quality, soil acidity, nutrient deficiencies and lack of appropriate technologies are amongst the major constraints to crop production in most parts of North West Ethiopia. Soil acidity, a major problem in the high rainfall areas, may be intensified partly due to the use of ammonium containing fertilizers. The objective of this work was to assess the effect of different N fertilizers and the rate of application on the dry matter, grain yield and protein content of wheat in acidic soils of North West Ethiopia in a field experiment. The nitrogen sources were (NH4)2SO4, Ca(NO3)2, KNO3, and CO(NH2)2, applied at rates of 0, 23, 46 and 69 kg ha− 1 of N in a randomized complete block design(RCBD) replicated three times in 2020 and 2021 main rainy season at the Agricultural Research Institute of Ethiopia, Debre Markos branch. A basal dose of NPS fertilizer at a rate of 100 kg ha− 1 was applied in each plot. The total N content in the grain of wheat plant was determined by the micro-Kjeldahl method. The result was that the grain yield and dry matter of wheat due to each N source and rate was significantly higher ( P < 0.05) than the plots that received NPS alone, the highest grain yield (2134 and 2241 kg ha− 1) being obtained from 69 kg ha− 1 of N from KNO3 and CO(NH2)2 sources, respectively. Total nitrogen and N efficiency was improved due to each applied N. The highest protein contents of wheat grain were obtained from the treatment of 46 kg Ca (NO3)2 and 69 kg ha− 1 N of KNO3, respectively. However, the use of these fertilizers by the local farmers requires further verification across many sites for longer periods of time and economic analysis of the yield of wheat vis-à-vis fertilizers for a correct appraisal of wheat production.