Background and Objective: Soil fertility depletion and soil acidity are critical problems for maize (Zea mays L.) production in westernEthiopia. Because of this, a field experiment was conducted on acidic Nitisols of the Assosa area to investigate the response of maize todifferent blended fertilizer rates and types. Materials and Methods: The treatments consists of control, three rates of N and P (92/46,115/57 and 138/69 N/P2O5 kg haG1) and two blended fertilizers with three rates (100 kg NPSB+73.9 kg N haG1, 150 kg NPSB+110.8 kg NhaG1 , 200 kg NPSB+147.8 kg N haG1 , 100 kg NPSZnB+75.1 kg N haG1 , 150 kg NPSZnB+112.6 kg N haG1 ) and 200 kg NPSZnB+150.2 kg N haG1. The experiment was laid out as a Randomized Complete Block Design with three replications. Results: The results revealed that fertilizer
types and rates significantly (p<0.01) affected grain yield, stover yield and harvest index. However, there was no significant difference between the two blended fertilizer types (NPSB and NPSZnB). The highest grain yield (7056.2 kg haG1 ) was recorded with 200 kg NPSZnB+150.2 kg N haG1 application. Blended fertilizers had improved nutrient concentration and uptake of maize. Application of 150 kg NPSB+110.8 kg N haG1 recorded the highest marginal rate of return and net benefit. Conclusion: The study demonstrates high improvement in grain and stover yield and nutrient uptake of maize in response to blended fertilizers implying that N, P, S, Zn and B are
deficient in Assosa soils, hence external application of these nutrients are vital as a blend for sustainable maize production.
