Effect of Blended Fertilizer Rate on Yield and Yield Components of Hybrid Maize (Zea mays L.) Varieties under Irrigation Condition in Low Land Area of South Omo Zone

Maize is an important cereal crop in Ethiopia. However, the yield of this crop is limited due to the lack of varieties and blended fertilizer for varieties and site specifications. The use of a right 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 at a 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 (BH-140, BH-540 and MH-140) and four NPSB blended fertilizer rate including kg ha-1(none fertilizer, 50 NPSB, 100 NPSB, and 150 NPSB). Factorial combinations were used as twelve treatments laid out in a randomized complete block design with three replications. Phenological and growth parameters, as well as yield and yield components data, were collected and subjected to analysis of variance using the SAS software program. 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 indicated that the highest grain yield (3624.0 kg ha-1) and net benefit (45,324 Eth-birr ha-1) with MRR of 2123.5 % were obtained from BH-540 variety treated with 100 kg ha-1 of NPSB fertilizer rates at Dasenech location. Whereas, at the Nyangatom location, the highest grain yield (4324 kg ha-1) and net benefit (54,774 Eth-birr ha-1) with MRR of 2968.5 % were obtained from MH-140 variety treated with 100 kg ha-1 of NPSB fertilizer rates. Therefore, based on the yield response and, cost and return analysis indicated, it is recommended BH-540 variety treated with 100 kg ha-1 of NPSB blended fertilizer rates for Dasenech location, while MH-140 variety treated with 100 kg ha-1 of NPSB blended fertilizer rates for Nyangatom location and their similar soil conditions and agro-ecology.