Determination of Water Requirement and Crop Coefficient of Wheat Crop in Central Ethiopia

Abstract

Accurately estimating a crop’s seasonal water needs is pivotal for effective irrigation project design, establishment, and management, as well as for scheduling irrigation. This study aimed to ascertain the seasonal crop evapotranspiration (ETc) and crop coefficient (Kc) of wheat across various developmental stages.  The research was carried out at the Debre Zeit Agricultural Research Center in central Ethiopia during the dry season of 2021/22. The crop considered for the experiment was durum wheat of Utuba variety. Two non-weighing lysimeter units were employed to measure the water balance components. The soil moisture was monitored using gravimetric method on daily basis conducted both before and after each irrigation event at various depth intervals. Using weather data and the modified Penman Monteith method, reference crop evapotranspiration (ETo) was determined, while crop evapotranspiration was calculated employing the water balance equation. The study found that during the initial, development, middle, and late stages of growth, water requirements were 40.35 mm, 82.44 mm, 238.66 mm, and 31.3 mm, respectively. Additionally, crop coefficients for the early, development, middle, and late stages of wheat growth were computed as 0.51, 0.83, 1.29, and 0.52, respectively. These findings provide valuable insights for precise water resource planning and management in wheat cultivation.