Effects of NPSB and foliar application of copper fertilizers on yield and yield components of maize in Halaba, Southern Ethiopia

Maize is one of the most economically important cereal crops produced by millions of farmers in Ethiopia. It is believed that practical information on the use of multi-nutrient fertilizer blends involving the actual limiting nutrients for specific site and crop may improve maize production and contribute to food security. Hence, an experiment was conducted in 2016 and 2017 cropping season to evaluate NPSB with and without Cu fertilizer and to determine the optimum rate for maize production in Halaba area. NPSB fertilizer with and without Cu was arranged in nine treatments. The treatments were:(1) no fertilizer (control), (2) NPSB: 69 kg N + 23.5 kg P + 10 kg S + 1.07 kg B/ha, (3) NPSB: 92 kg N + 31 kg P + 13 kg S + 1.4 kg B/ha, (4) NPSB: 115 kg N + 39 kg P + 17 kg S + 1.7 kg B/ha, (5) NPSB: 138 kg N + 15.7 kg P + 10 kg S + 1.07 kg B/ha, (6) NPSBCu: 69 kg N + 23.5 kg P + 10 kg S + 1.07 kg B + 0.625 kg Cu/ha, (7) NPSBCu: 92 kg N + 31 kg P + 13 kg S + 1.4 kg B + 0.625 kg Cu/ha, (8) NPSBCu: 115 kg N + 39 kg P + 17 kg S + 1.7 kg B + 0.625 kg Cu/ha and (9) NPSBCu: 138 kg N + 15.7 kg P + 10 kg S + 1.07 kg B + 0.625 kg Cu/ha. Two farms were used for the trial and the treatments were arranged in a randomized complete block design (RCBD) replicated three times. Different crop parameters were measured and analyzed using SAS 9.3 program. Economic analysis was also performed to investigate thefeasibility of fertilizer treatments for maize production. Based on statistical analysis, ttreatment 5 (NPSB: 138 kg N + 15.7 kg P + 10 kg S + 1.07 kg B/ha) gave significantly higher maize yield compared to all other fertilizer treatments and the control. The highest net benefit (33,329 ETB/ha) was also obtained from this treatmentwith acceptable marginal rate of return (557%) even under the projected 20% input price increment.