EFFECTS OF IRRIGATION METHODS AND SCHEDULING ON WATER AND ONION PRODUCTIVITY IN SEMI-ARID AREAS OF ETHIOPIA

How to meet the crop water demand and improve crop productivity is a particular concern for small-scale farmers, where the availability of water resources is limited. This study evaluated three different irrigation methods (furrow, basin and border) and two types of irrigation scheduling (CROPWAT schedule and farmers' practices) with three replica-tions for two consecutive years (2016-2017) at two sites using onion crops. The results showed that the CROPWAT schedule, basin irrigation method, and their interactions showed better performances and produced higher yield and water produc-tivity. An average of 26 and 27 metric tons/hectare of onion were obtained under the basin irrigation method and basin irrigation with CROPWAT schedule combined, respectively. The water productivity (WP) and irrigation water productivity (IWP) also showed higher results under the basin irrigation method compared to other treatment combinations. The basin irrigation method produced higher marketable onion bulbs with firm medium bulb sizes that are essential for onion produc-ers to earn maximum profit. The findings of this study also indicate that focusing on enhanced irrigation scheduling tech-niques and irrigation methods is paramount for better onion productivity in irrigation water-limited areas.