Effect of surge flow and alternate irrigation on the irrigation efficiency and water productivity of onion in the semi-arid areas of North Ethiopia

The study was conducted in the semi-arid areas of northern Ethiopia with the objective of evaluating the effect of surge flow and alternate irrigation on irrigation performance indicators, water use efficiency and crop yield. The experiment consists of two factors, irrigation systems (alternate furrow (Af) and conventional furrow (CF)) and irrigation flow methods (continuous (C), Surge 1 (S1), Surge 2 (S2), and Surge 3 (S3)). Eight treatment combinations replicated three times were arranged in a factorial randomized complete block design. Onion crop was used as indicator crop for the experiment because of its dominant and cash crop in the region. The result of this experiment indicated that the interaction effect of the irrigation system and irrigation flow methods did not show statistically significant difference on the performance indicators, crop yield and water use efficiency. The irrigation system (Af and CF) as a factor has not significant effect on yield of onion. However, the irrigation flow methods (C, S1, S2 and S3) were significantly affected the irrigation performance indicators (application efficiency, distribution uniformity, deep percolation and tail water runoff losses) and likewise, irrigation water use efficiency and yield of onion were significantly different. Higher crop yield (13208 kg/ha), water use efficiency (1.96-2.55 kg/m3), application efficiency (52.9-58.7%) and distribution uniformity (81.4-86.2%) were obtained from both surge flow and alternate irrigation as compared to continuous flow and conventional furrow irrigation (every furrow water application) which was recorded less 10142 kg/ha, 1.36-1.65 kg/m3, 44-54.7%, 67.1-79.6%, respectively. The result of this study explicitly showed that demonstration of these irrigation methods can enhance the poor water management practices in the semi-arid areas of Ethiopia and elsewhere in the world with limited water resources and similar soil characteristics. The authors of this paper recommend the farmers, irrigation experts, water resources managers and decision makers in the region to apply those techniques for improving water use efficiency.