Response of Malt Barley to NPSZnB and Urea Fertilizers Across Soil Types and Agro-ecologies, Arsi Zone of Oromia, South-Eastern Ethiopia

Field trials were conducted on farmers’ fields during the 2017, 2018, and 2019 cropping seasons to determine the optimum NPSZnB and urea fertilizer rates for selected crop, soil, and climatic conditions, as well as to assess the economic feasibility of blended and urea fertilizer rates for malt barley by varying levels of NPSZnB fertilizer (0, 100, 150, 200, 250 kg ha-1) and recommended NP in combined RCBD with three replications on growth performance and yield. The post-harvest soil analysis results of experimental sites revealed that the use of treatments significantly (p< 0.05 and p< 0.001) altered pH, total N, available P, and organic matter for samples taken from malt barley crop experimental sites. Application of different fertilizer levels significantly affected post-harvest pH and organic carbon contents. A significant improvement was observed in soil chemical contents compared to the contents of the soil before treatment application at Lemu-Bilbilo district. Combined levels of NPSZnB and urea fertilizer rates significantly affected grain and above-ground biomass yields at Lemu-Bilbilo and Kofele districts. The maximum grain and biomass yield (6197 and 11018 kg ha-1) in 2019 and minimum (3646 and 6875 kg ha-1) in the 2018 cropping season were obtained, respectively at Lemu-Bilbilo district up on the application of NPSZnB and urea fertilizers. Similarly, significant grain and biomass yield (5554 and 10412 kg ha-1) were obtained from the application of 250 + 200 and 250 + 150 kg ha-1 NPSZnB with urea fertilizer, respectively. The maximum grain and biomass yield (5244 and 10092 kg ha-1) in 2019 and minimum (3477 and 7736 kg ha-1) in 2017 and 2018 cropping season were obtained, respectively at Kofele district from the application of NPSZnB and urea fertilizers. Similarly, a significant grain and biomass yield (5125 and 9826 kg ha-1) were obtained from the application of 250 + 150 and 250 + 200 kg ha-1 NPSZnB + urea, respectively.