Evaluation of the FAO CROPWAT model for deficit-irrigation scheduling for onion crop in a semiarid region of Ethiopia
Journal of Applied Horticulture
Amhara Regional Agricultural Research Institute, Sekota, Ethiopia; School of Agricultural and Wine Sciences, Charles Sturt University, Locked Bag 588, Wagga Wagga, NSW 2678, Australia
Deficit irrigation conserves water and minimizes adverse effects of excess irrigation. In this study, the applicability of the CROPWAT model in management of deficit irrigation was evaluated at Sekota Agricultural Research Center, Ethiopia. Water was applied using low head drippers. There were eight treatments with three replications: stress at 1st, 2nd, 3 rd, and 4th growth stages and partial stresses of 50% ETc, 75% ETc with two controls of 25% ETc and 100% ETc of the water requirement throughout the growing season. The input data for CROPWAT program were climatic, rainfall, crop and soil data. Yield reductions simulated by CROPWAT program were comparable with yield reduction measured under field condition. Model efficiency and correlation coefficients of 98% were obtained. Based on the above comparative analysis, CROPWAT program could adequately simulate yield reduction resulting from water stress.