Impact of water requirement on yield productivity of potato crop using lysimeters under arid climate

The Kingdom of Saudi Arabia (KSA) is currently 121% selfsufficient in potatoes.1 In 2010, the country’s potato crop encompassed a land area of 6,941 ha, with production of approximately 176,077 tons.2 The successful irrigation of potato requires an understanding of both irrigation and scheduling methods, as a regular water supply is needed to secure high yields.3 Potato is often considered to be a highwater-use crop,4 with yield quantity greatly influenced by the amount of applied water.5,6 In agriculture, quantifying evapotranspiration (ET) is essential for effective irrigation management.7 In the KSA, water requirements for potato crops average around 590 mm and 710 mm in the autumn and spring seasons, respectively.8 In eastern Saudi Arabia, Al-Omran and Shelby9 estimated the total crop water requirement of potatoes to be approximately 520 mm, whereas Al-Ghobari10 calculated a water requirement of 416 mm for the winter season in Najran. In contrast, Wright and Stark reported seasonal water consumption values in irrigated areas of Oregon and Washington between 640 mm and 700 mm, demonstrating the variation that exists in water use depending on factors such as environment, season, and rate of crop growth. Lysimeter is generally consider as the criterion system for estimating crop evapotranspiration (ETc) and crop coefficients (Kc); as such, measurements of the water requirements of potato crops can be attained using lysimeters, which provide more reliable measurements of ETc that, in turn, allows for more precise estimates of irrigation water depths.11,12 ETc measurements are used for different crops grown in Saudi Arabia,13,14 and a standardized reference ET approach is commonly used to determine daily reference ET.15 The crop coefficient varies through the course of the growing season, depending on the growth stage of the crop.16