Utilizing the modern technologies in agriculture such as subsurface water retention techniques were developed to improve water storage capacities in the root zone depth. Moreover, this technique was maximizing the reduction in irrigation losses and increasing the water use efficiency. In this paper, a polyethylene membrane was installed within the root zone of okra crop through the spring growing season 2017 inside the greenhouse to improve water use efficiency and water productivity of okra crop. The research work was conducted in the field located in the north of Babylon Governorate in Sadat Al Hindiya Township seventy-eight kilometers from Baghdad city. Three treatments plots were used for the comparison using surface trickle irrigation system: Polyethylene sheet (SWRT) was used in plot T1, controlled irrigation in plot T2 and uncontrolled irrigation in plot T3. Irrigation quantities, time of irrigation, soil water contents were measured for all treatments plots. The results indicated that water use efficiency for the three experimental plots, T1, T2, and T3 were: 2.43, 1.94 and 0.98 kg/m3, respectively. The increasing value in water use efficiency of T1 plot compared with T2 and T3 plots were 25 and 148 %, respectively. Additionally, the water productivity of okra crop for T1, T2, and T3 plots was: 12800.9, 8744.8, and 4736.3 ID/m3, respectively. The increasing value of the water productivity of T1 compared with plots T2 and T3 was 46 and 170 %, respectively. From this study, the benefit of using membrane sheet below the soil surface resulted in an increase in the value of yield, water use efficiency and water productivity. Moreover, saving water and reduced the water losses by deep percolation were resulted.
