Effect of furrow irrigation methods and deficit irrigation levels on yield and water productivity of onion (Allium cepa L.) at Amibara, Middle Awash Valley, Ethiopia.

Abstract Background: Deficit irrigation is one of the techniques used to enhance water productivity without significant yield loss in semiarid areas. Methods: A field experiment was conducted at Werer, Middle Awash Valley during the dry season of 2017/18, 2018/19 and, 2019/20 for three consecutive years to investigate the effects of deficit irrigation levels and furrow irrigation methods on onion yield and water productivity. Split plot design with three replications, in which the irrigation methods (Conventional, Fixed and Alternate Furrow) were assigned to the main plot and the three deficit levels (100% ETc, 75% ETc and 50% ETc), were in the sub-plot. Results: Results indicate that marketable onion bulb yield and water productivity were highly affected by the interaction effect of furrow irrigation methods and irrigation levels (p < 0.05). The highest bulb yield (17580.43 kg ha-) and water productivity (11.79 kg/m3) were obtained from conventional furrow irrigation method with100% ETc and alternate furrow irrigation with 50% ETc respectively. Considering water saved and maximum yield, Onion irrigated by AFI 100% ETC resulted in a 15% yield reduction with up to 50% irrigation water saving as compared to CFI 100% ETc. Conclusion: The present study suggests that, under water limiting conditions, adopting alternate furrow irrigation with 100% ETc can be an alternative to increase water productivity without significant yield reduction.