Abstract Although Ethiopia has abundant rainfall during the monsoon, its agricultural system does not yet fully benefit from the technologies of optimal agricultural water management during the dry season when water supplies are short. Therefore, there is need to investigate the potential of simple water saving irrigation technologies for farmers. In this study two different irrigation scheduling methods were compared: irrigation scheduling by Wetting Front Detector (WFD) and soil water balance by measuring soil moisture using Time Domain Reflectometry (TDR). Eighteen farmers, grew the same onion variety, were randomly assigned to the two irrigation management practices. The experimental plot size varied between 100 m2 and 230 m2.Recommended crop management and fertilizer application rates were maintained for all farmers. The average amount of water applied in the WFD plots was 24% lower than for TDR. Larger variability among the TDR farmers was found both in irrigation quantity and yield. Differences in yield, water productivity and water use efficiency between both irrigation treatments were not significant. The study shows that using the WFD tool could guide farmers on how much to irrigate, reducing the amount of water without affecting crop yields.