Assessment of irrigation water quality of lowlands in the Bale Zone, South Eastern Oromia, Ethiopia

Abstract

Water quality concerns have been very crucial because good quality water supplies in abundance and readily available for production and productivity is of great importance. Therefore, the study was conducted to assess irrigation water quality of the lowlands of Delo Menna and Berbere districts. The samples were collected from the upstream and downstream of the canals along the farms of the districts during the medium and low peaks of the rivers' flow. About 1 L of water sample was collected from each site. Likewise, the sampling date was on the 15th of designated months. Accordingly, the results reveal that the surface irrigation water has less salinity, sodium hazard and residual sodium carbonate hazard in the irrigated canals and canals along the farms. The electrical conductivity ranges from 0.17 to 0.49 ds/m at lower peak and from 0.06 to 0.24 ds/m at medium peak in Delo Menna district. Moreover, the residual sodium carbonate ranges from 1.34 to 2.57 at lower peak flow and 0.79 to 1.30 at medium peak flows; sodium concentration ranges from 0.36 to 0.46 meq/L at lower peak of the river flow and very small concentrations at the medium peak flow period in Berbere district. The salinity indicator parameters such as all cations and anions, total dissolved solid, adjusted sodium ratio, residual sodium carbonates in the irrigated rivers were low in Delo Menna and Berbere. Therefore, the rivers in both districts are normal for agricultural production of all types of crops which are grown in the low lands of Bale.