Optimum Irrigation Rate for Drip Irrigated Maize Grown In Semi-Arid Conditions of Upper Egypt

摘要

Shortage of water in arid and semi-arid maize production systems increases the need of applyingdeficit irrigation. A two-year field study in the semi-arid region of Upper Egypt was carried out in a randomizedcomplete block design (RCBD) during the summer seasons of 2014 and 2015. Maize plants were irrigated by 8276or 6207 m3 ha 1 (100 or 75% of water requirements, I and I ). Uptake of N and K by maize irrigated by I100 75 100increased by 11and 7% in the first season and by 13 and 15% in the second season compared to I75. Increasingthe irrigation level to 100% caused a 20 and 6% increase in the straw yield in the first and second season,respectively, also it caused a 20% increase in the biological yield in the first season. The grain yield of maizeirrigated by I75 was higher by 5 and 10% in the first and second season, respectively, as compared to I100. Wateruse efficiency (WUE) was higher by 41and 56% in the first and second season, respectively, in the case of I75as compared to I100. The data of the current study indicated that slightly water stress caused a slightlysignificant reduction in the straw and biological yield of maize and saved 2000 m3 of water, moreover, it causeda slightly significant increase in the grain yield.