The effect of different irrigation levels on water use efficiency on the basis of maize grain and soil moisture variations

The research in the response of plants to deficit irrigation in the regions with limited water resources is very important and leads to reducing water usage in agriculture. This study has been conducted in 2014-2015 in the research field located in Dezful Islamic Azad University in Khozestan as complete randomize block design in four treatments and four replications, 60%, 80%, 100% and 120% of water requirement of maize (KSC.704) under surface irrigation system. Growing season was divided to four periods in which soil water was determined in different soil depths. Grain yield and water use efficiency were determined in the last growth stage. The results show that there is significant difference (1%) in the effect of different irrigation levels in the grain yield. Irrigation treatment of 120% of water requirement increased maize grain yield. Irrigation treatment of 60% plant water requirement decreased vegetative growth because it leads to delaying pollination maturation and yield. Maximum and minimum water used efficiency on the basis of grain yield were related to 80% (2.07 kg/m3) and 60% (1.35 kg/m3) water use efficiency, respectively. Also, there was difference between treatments in soil moisture of different soil depths.