Bread wheat is a major staple and cash crop in Ethiopia, including the study area. Its productivity is constrained by soil nutrient deficiencies and the lack of location-specific fertiliser recommendations. Accordingly, a field experiment was conducted to determine agronomically and economically optimal rates of potassium and blended nitrogen, phosphorus, sulfur and boron (NPSB) fertilisers for bread wheat production in southern Ethiopia. The treatments were factorial combinations of 3 K fertiliser rate levels and five blended NPSB levels, arranged in a randomised complete block design (RCBD) with 3 replications. Agronomic parameter data were documented for every treatment. The findings indicated that both main effects significantly (p<0.01) impacted most agronomic parameters and the agronomic efficiency (AE) of NPSB. Exceptionally, harvest index (HI) and thousand kernel weight (TKW) were solely impacted by NPSB rates. Grain yield (GY), straw yield (SY), above-ground dry biomass (ABM) and the total number of tillers (TNT) were all greatly impacted by the 2 fertilisers' interaction effect. The combined application of 150 kg NPSB + 50 kg K ha-1 exhibited the maximum AGBM (12179 kg ha-1) and GY (5929 kg ha-1). Therefore, the application of 150 kg NPSB combined with 50 kg K ha-1 is recommended for bread wheat production in the study area.
Triengo et al. (2026) studied this question.