Agronomic and Physiological Efficiency of Maize (<i>Zea mays</i> L.) Hybrids as Influence by Nitrogen Fertilization in Semi-Arid Areas of Ethiopia

Maize is one of the major food crops in semi-arid areas of Ethiopia. Efficient application of N fertilizer on maize crop enables smallholder farmers have a synergic effect through enhancing yield productivity, reducing cost of production and nitrous oxide emission to the atmosphere exacerbating the challenges of changing climate. This experiment was conducted to determine the effect of nitrogen fertilizer on yield and yield related traits and assess the relationship between yield and nitrogen use efficiency indices. Eight maize hybrids were evaluated at three rates of N fertilizer (0, 32.5 and 65 kg N/ha) using split-plot design with three replications at two locations (Dera and Melkassa) in 2020 main cropping season. The results from analysis of variance (ANOVA) at each location indicated that majority of yield and yield related traits, agronomic and physiological efficiency were significantly influenced either by one or two of the factors (nitrogen and genotype) and/or the interaction effect of the two at both locations. The results of combined ANOVA over locations revealed that the interaction of the three factors (location, nitrogen and genotype) had significant effect on agronomic and physiological efficiency. The hybrids WE7201 and WE8206 had obtained the highest agronomic (27.67 kg kg<sup>-1</sup>) and physiological efficiency (43.52 kg kg<sup>-1</sup>) due to the application of 32.5 kg N ha<sup>-1 </sup>respectively. Thus, WE7201 and WE8206 could be recommended for production in the study areas.