Evaluation of NPSB Fertilizer Levels on Yield and Yield Components of Open Pollinated Maize (Zea mays L.) Varieties Under Irrigated Condition in South Omo Zone

Maize is a significant cereal crop in Ethiopia. However, the yield of this crop is limited due to lack of varieties and blended fertilizer for varieties and site specifications. The use of exact amount of fertilizer based on crop requirement has significant importance for sustainable crop production. A study was undertaken to investigate the effects of NPSB blended fertilizer rate for maize yield production in Dasenech and Nyangatom districts in the lowland area of South Omo Zone, Southern Ethiopia during the 2019/2020 cropping season. The experiment was factorial with three maize varieties (Melkassa-6Q Melkassa-4 and Melkassa-2) and four NPSB blended fertilizer rates including kg ha-1 (none fertilizer, 50NPSB, 100NPSB and 150 NPSB). Factorial combinations were used as twelve treatments laid out in a randomized complete block design with three replications. Growth, yield and yield components parameters were recorded and carried out statistical analysis The result of analysis of variance revealed that the interaction effect of varieties and blended fertilizer rate highly significant difference in grain yield. The result showed that the highest grain yield (3913.3 kg ha-1) and net benefit (49,229.6 Eth-birr ha-1) with MRR of 2525.83% were obtained from Melkassa-2 variety treated with 100 kg ha-1of NPSB fertilizer rates at Dasenech location. Whereas, at Nyangatom location, the highest grain yield (4906.7 kg ha-1) and net benefit (62640.45Eth-birr ha-1) with MRR of 2926.2% were obtained from similar Melkassa-2 variety treated with 100 kg ha-1 of NPSB fertilizer levels s. Therefore, based on the result recorded from this study Melkassa-2 varieties treated with 100 kg ha-1 of NPSB blended fertilizer can be suggested as profitable for the production of maize at both districts of the study areas and their similar soil conditions and agro-ecology.