Effect of Interval and Depth Irrigation on Water Use Efficiency, Cucumber Productivity under Green House Conditions and Drip Irrigation

Abstract

A field experiment was conducted to study the effect of intervals and depths irrigation on water use efficiency and productivity of Cucumber under drip irrigation system. It was carried out during fall season 2021 in Al-Saqlawia, far about 45km southeast of Al-Ramadi, located at longitude 33° 24’ 57’' E and latitude 33° 24’ 57’' N. The experiment included two factors; the first is irrigation interval (I) which included two-days interval (I2) and four-days interval (I4). While the second one is irrigation depth which included 100% water depth and 50% water depth. The drip irrigation system was evaluated at operational pressure 50 kPa (0.5 bar) in order to determine the closest actual discharge to the design discharge, and calculating the uniformity coefficient and discharge variance. The results showed that 50kPa operational pressure gave an actual discharge of 3.94 Lh−1, which was the closest to the design discharge 4Lh−1, highest uniformity coefficient of 96.61% and lowest variance of 9.58%. While the highest yield achieved was 108 and 80-ton ha−1 at water depth (d50) for two irrigation interval 2 and 4 days compared to the lowest yield of 50 and 70-ton ha−1 at water depth (d100) for the same irrigation interval, respectively. While the highest water use efficiencies achieved was 20.9 and 15.48 kg m−3 at depth (d50) for 2-day and 4-day intervals, respectively. Finally, the best value for crop water consumptive use was obtained under drip irrigation system of 51.6 cm season−1.