Effects of Irrigation Methods and Scheduling on Water and Onion Productivity in Semi-Arid Areas of Ethiopia

Highlights Irrigation experiments on onion productivity were conducted at two sites for two consecutive years in Ethiopia. Factors from irrigation interval and irrigation method analyzed independently and factorially. Basin irrigation and fixed irrigation produced higher bulb yields and water productivity. Farmers’ income can be enhanced using improved irrigation practices for increased onion productivity. Abstract. 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 replications 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 productivity. 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 producers to earn maximum profit. The findings of this study also indicate that focusing on enhanced irrigation scheduling techniques and irrigation methods is paramount for better onion productivity in irrigation water-limited areas. Keywords: Irrigation interval, Irrigation methods, Irrigation practices, Onion productivity, Water management.