Optimum rate of nitrogen fertilization for drip irrigated maize under semi-arid conditions

Water and nitrogen are major limiting factors for crop growth and development in arid regions. A field experiments were carried out at the semi-arid region of Upper Egypt, Assuit governorate during 2014 and 2015 growing seasons. The experiments were conducted to investigate the response of drip irrigated maize to three levels of nitrogen (N) fertilization (N220=220, N290=290, and N360=360 kg ha−1). The measured growth parameters of maize were significantly higher when N was applied at a rate of 360 kg per hectare compared to other N rates (220 and 290 kg ha−1). The highest N supply (N360) increased the uptake of N, P, and K by 43, 41, and 53%, respectively, as compared to the lowest rate (N220). N360 increased maize grain yield by 56 and 62% in the first and second season, respectively, as compared to N220. N360 increased the water use efficiency (WUE) by 54 and 40% in the first and second season, respectively, compared to N220. Based on the obtained results, it is recommended to fertilize drip irrigated maize by 360 kg per hectare.