Evaluation of drainage water quality for irrigation reuse in Kulfo and Hare irrigation command areas, southern Ethiopia

Abstract

Water from agricultural drainage systems can be reused when its quality is good or blended with irrigation canal water to overcome the water shortage. The primary goal of this research was to determine the quality of surface drainage water in the Kulifo and Hare irrigation projects for irrigation reuse. Water quality was evaluated in situ and in the laboratory during the irrigation season of 2022. Turbidity, TDS, pH, EC, and DO were analyzed in the field using an Aqua meter. Fifty-seven water samples were collected and analyzed for the major cation (Na+, Ca2+, K+, and Mg2+) and anion (HCO3−, CO32−, Cl−, and SO42−). The result of the drainage water quality index study, according to the water quality index for irrigation purpose reuse, ranged from 47.84 to 84.89. This indicated that the suitability of drainage water reuse for irrigation purposes was categorized as ‘poor to very poor,’ except in Shara community-managed farms. Therefore, to avoid the impact on soil quality for crop production due to the hazard of poor agricultural drainage water for irrigation reuse in the study area, it needs to be treated before being reused for irrigation purposes, except at the Shara irrigation community-managed farm. HIGHLIGHTS Drainage water quality suitability for irrigation purposes.; Chemical and physical factors affect the drainage of water quality for irrigation reuse.; Scientific evidence and appropriate agricultural drainage water quality index.; Agricultural land drainage water quality suitability for irrigation water reuse.; Aqua meter used direct measure of water quality factors resulting in the field.;

Keywords

• irrigation reuse
• irrigation water quality
• surface drainage water
• water quality index