EFFECT OF DEFICIT IRRIGATION UNDER DRIP IRRIGATION METHOD ON THE YIELD AND WATER USE EFFICIENCY OF ONION (Allium cepa L.) AT FOGERA DISTRICT, NORTHWESTERN ETHIOPIA

Abstract

Water has been identified as one of the scarce inputs, which can severely restrict agricultural production and productivity unless it is carefully conserved and managed. Deficit irrigation improves water productivity and irrigation management practices resulting in water saving by maintaining soil moisture content below optimum level throughout growth season. Hence, a field experiment was conducted in Amhara region, South Gonder zone, at Fogera district during the dry season of 2020 using deficit irrigation under drip irrigation method to evaluate the effect of deficit irrigation practices on yield and water use efficiency (WUE) of onion. The experiment was carried out in randomized complete block design with three irrigation treatments (drip irrigation at 100%, 80% and 60%ETC) and three replications. Drip irrigation at 100%ETc gave very highly significant onion yield (26.8 t ha-1 ), as compared to 80% and 60%ETc irrigation treatments. However, irrigation water use efficiency was found highest (6.2 kg m -3 ) with drip irrigation at 80%ETc. The amount of water saved at 80% and 60%ETc under drip irrigation method were 90mm, and 179.9mm respectively over 100% drip irrigation method and this may sufficient to irrigate 0.2 to 0.4 hectare of additional area of onion crop as compared to that of 100%ETC drip irrigation method. Therefore, this study suggests that farmers in the study area, having limited amount of water for irrigation, should adopt deficit irrigation under drip irrigation method.