Limited water availability in arid and semi-arid wheat production systems
increases the need of applying efficient drip irrigation systems. However,
there is little information available about the optimum level of nitrogen (N)
fertilization for drip-irrigated wheat. A two-years field study in the semi-arid
region of Upper Egypt was carried out in a randomized complete block
design to investigate the response of drip-irrigated wheat to three levels of N
fertilization (N120 D 120, N180 D 180, and N240 D 240 kg ha¡1). N240 increased
the uptake of N, P, and K by 66.3, 48.6, and 43.5%, respectively, as compared
to N120. The application of N240 increased the grain yield by 28.4 and 40.4%
and water use efficiency by 27.6 and 41.8% the first and second season,
respectively, as compared to N120. Based on the obtained results, it is
recommended to fertilize drip-irrigated wheat by 240 kg ha¡1.