Abstract
Background and Objective: Soil fertility depletion and soil acidity are critical problems for maize (Zea mays L.) production in western Ethiopia. Because of this, a field experiment was conducted on acidic Nitisols of the Assosa area to investigate the response of maize to different 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 ha–1) and two blended fertilizers with three rates (100 kg NPSB+73.9 kg N ha–1, 150 kg NPSB+110.8 kg N ha–1, 200 kg NPSB+147.8 kg N ha–1, 100 kg NPSZnB+75.1 kg N ha–1, 150 kg NPSZnB+112.6 kg N ha–1) and 200 kg NPSZnB+150.2 kg N ha–1. 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 ha–1) was recorded with 200 kg NPSZnB+150.2 kg N ha–1 application. Blended fertilizers had improved nutrient concentration and uptake of maize. Application of 150 kg NPSB+110.8 kg N ha–1 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.
