Optimizing yield and water use efficiency of furrow-irrigated potato under different depth of irrigation water levels

Development of optimum irrigation water management is important for water productivity and food security enhancement. Hence, introducing the knowledge of crop-specific irrigation water requirement is crucial. This study aims at investigating crop water requirement, water use efficiency, and yield of potato at different water regimes for better potato productivity. This study was conducted in Emba Alaje district, southern zone of Tigray regional state, Ethiopia. The crop water requirement of potato was estimated using CROPWAT 8 software and determined as 604 mm for the whole growing period. Potato crop was grown under seven treatments of irrigation water application in complete randomized blocks design with three replications each. Potato yield and water use efficiency (WUE) were significantly (p < 0.05) affected by depth of water application. The highest yield and WUE was obtained from 100% of ETc (25864 kg/ha) and 55% of ETc (6.08 kg/m³) respectively. Irrigation water application with 70% of ETc produces yield and WUE of (22639 kg/ha) and (5.4 kg/m³), respectively, and this has no significant difference with 100% ETc. Application of 423 mm irrigation water (70% of gross irrigation) is an optimum amount to improve both yield and WUE. These results encouraged application of deficit irrigation up to 30% of ETc can save significant amount of irrigation water without substantial yield reduction. The authors of this study would like to recommend farmers and irrigation experts to apply 70% of ETc as deficit irrigation to enhance irrigation water productivity in areas where water is a limiting factor.