Ashebir Haile Tefera
Effective agricultural water management technologies improve crop and water productivity by allowing for a more efficient use of inputs, such as water and fertilizer, and by enhancing the yields and quality of the crops farmers grow. The aim of the study was to determine the optimal irrigation scheduling and fertilizer rate for better water use efficiency under irrigated agriculture. The experiment was carried in the randomized completed block design experimental design with combination of five levels of irrigation treatments and three levels of fertilizer rate with three replications of the treatments. The result revealed that the plot received optimal irrigation interval of 14 days in combination of 25% more than the recommended fertilizer rate (292.24 kg/ha) had significantly higher effects on above ground biomass (18.25 t ha-1) and on grain yield (4.8 t ha-1 ) of irrigated maize in the study area. However, the maximum water use efficiency of 2.05 kg/m3 was obtained at the irrigation interval of14 days and highest level of fertilizer rate. Hence, the use of 14 days optimal irrigation interval and 25% more fertilizer than the recommended rate is advisable because the grain yield and crop water use efficiency had been improved in the study area. Therefore, the obtained results are valuable in improving maize yield and water use efficiency, but economic analysis should be included for further recommendation.