Effect of blended fertiliser application on bread wheat yield, agronomic efficiency and profitability on Nitisols of Southern Ethiopia

Abstract

Continuous use of only N and P fertilisers that depletes secondary and micronutrients has been presented as a major cause for low wheat yields (2.2 t/ha) in the Ethiopian highlands. In this study, on-farm trials were conducted to compare the effects of multi-nutrient blended fertilisers on the wheat yield on Nitisols in southern Ethiopia. Five quantities of fertiliser blend (50, 100, 150, 200, 300 kg NPS + ZnB kg/ha) were compared against a newly introduced compound fertiliser (150 kg/ha NPS) and the conventionally used NP (Di-Ammonium Phosphate DAP) fertiliser at 150 kg/ha. Treatments were arranged in a randomized complete block design (RCBD) and replicated five times using farm fields as replicates. Results revealed that application of 200 and 300 kg/ha of NPS + ZnB blend fertiliser produced significantly (p < 0.01) higher biomass (16.9 t/ha) and grain yield (3.7 t/ha) than the lower amounts. However, the marginal rate of return was highest for 100 kg NPS + ZnB/ha, but compared with DAP, the blend fertiliser did not produce significantly higher yield. Conversely, the agronomic nutrient use efficiency was significantly higher for NPS + ZnB blend suggesting the importance of balanced fertilization.