Agricultural and Biological Research

Response of improved sorghum varieies to nitrogen ferilizer rates in the middle scope of Habru district, Northeastern Ethiopia

Mohammed Hussen*, Moges Tadesse and Alemu Molla

Sorghum, a vital staple food crop cultivated by subsistence farmers in Ethiopia, is traditionally grown with minimal or no fertilizer inputs. To evaluate the response of improved sorghum varieties to varying nitrogen fertilizer rates, a field experiment was conducted in three locations within the Habru district (Sirinka, Mersa and Libso) during the 2019/2020 and 2020/2021 cropping seasons. The study employed a randomized complete- block design with three replications, combining five nitrogen levels (0, 46, 69, 92 and 115 kg ha^-1) with two improved sorghum varieties (Melkam and Girana-1). Significant (P<0.05) variations were observed in all parameters due to the interaction effects of nitrogen and sorghum varieties. Grain yield and yield-related characteristics of the sorghum varieties exhibited an increasing trend as nitrogen levels increased from 0 to 92 kg ha^-1. Remarkably, the application of 92 kg ha^-1 nitrogen fertilizer rate resulted in the highest sorghum grain yield, reaching 4.77 tons/ha. The partial budget analysis revealed that the Melkam treatment, with an application rate of 92 kg N/ ha, yielded the highest marginal rates of returns (3666.47%). These findings strongly indicate that utilizing the Melkam variety along with 92 kg N/ha can significantly enhance sorghum production, both in terms of quality and economic viability. Consequently, it is highly recommended for adoption not only in the study area but also in regions sharing similar agro ecological characteristics.