Influence of Nitrogen Fertilizer Rates on Growth, Yield, and Grain Quality of Durum Wheat (Triticum durum Desf) Cultivars in Central Ethiopia

Abstract

Appropriate nitrogen rate recommendation is one of the realistic ways to save nitrogen fertilizer in Ethiopia. The field experiments were conducted in two years of 2022 and 2023 GC on heavy black soil to investigate the effect of nitrogen fertilizer rates on durum wheat growth, yield, and quality in the central part of Ethiopia. The treatments of the experiments have five nitrogen rates (0, 46, 92, 138, and 184 kg N ha^–1) and two durum wheat cultivars (Mangudo and Utuba). The experiments were conducted in randomized complete block design in the factorial arrangement with three replications. The results showed that increasing nitrogen rates up to 138 kg N ha–1 resulted in significant improvements in all studied parameters, with the exception of starch content. Mangudo and Utuba cultivars exhibited the highest yield and quality responses to nitrogen treatments, respectively. The yield and quality of the tested cultivars increased with increased nitrogen rates, with the maximum values recorded at 138 kg N/ha. However, the cost-benefit analysis revealed that 92 kg N/ha has the maximum marginal rate of return compared to other nitrogen treatments for both cultivars. Furthermore, for every birr invested in Mangudo production, farmers can recover their investment and earn an additional 10.1 birr compared to Utuba production. Therefore, we recommend applying 92 kg N/ha as the optimal nitrogen rate for durum wheat production in the study area and similar agro-climatic regions.