Optimal Nitrogen and Phosphorus Fertiliser Rates for Maximising Food Barley Productivity in the Highlands of North Gondar, Ethiopia

Soils in the Ethiopian highlands are deficient in nitrogen (N) and phosphorus (P), limiting food barley productivity over many decades. This study aimed to determine the optimum N and P fertiliser rates for food barley production in the Central and North Gondar highlands of Ethiopia. Field experiments were conducted during the 2019 and 2020 cropping seasons at six sites using a randomized complete block design (RCBD) with three replications. Treatments comprised four nitrogen rates (46, 69, 92, and 115 kg ha⁻¹) and three P_2O5 rates (23, 46, and 69 kg ha⁻¹). The highest grain yields ranged from 2650.6 to 4160.8 kg ha⁻¹ across sites with 115 kg N ha⁻¹, while the highest combined mean yield (3150.8 kg ha⁻¹) was also obtained at this rate. However, partial budget analysis identified 92 kg N ha⁻¹ and 23 kg P_2O5 ha⁻¹ as the most economically profitable fertiliser combination, recommended for food barley production in the Central and North Gondar highlands of Ethiopia.