Assessment of Soil and Water Salinity Status of Bitata Small Scale Irrigation Scheme of Guji Zone Oromia, Ethiopia

Abstract

The Soil salinity, sodicity and water logging are becoming an emerging challenge for the irrigation development. So, assessments of irrigation schemes are very important to see the problems they have. The assessment of soil and water salinity status of Bitata small scale irrigation scheme of Guji Zone, Oromia region was done to identify, analyze and map salinity level using Geographic information System, the chemical properties of the soil was done at laboratory for samples analysis. After, spatial analyst and interpolation by Inverse distance Weight and Re-class the soil analyzed. Then the area of influence of the points was determined for the selected parameters and the results of investigation shows the majority of sample results are non-saline non sodic, even if, the samples were less, the sodicity problems occur at the study area on surface soil by considering three parameters at once and non-saline and non-sodic for profile soil. And when considering individual parameters of surface soil the results shows slightly saline depends on Electrical conductivity of saturation extracts, considering the exchangeable sodium percentage slightly to extremely sodic results was observed. And the results of irrigation water quality shows Very high Saline and Low Sodicity. The finding of the study recommends intervention of sodicity for surface soil and salinity and sodicity for water source used for irrigation is very important to control the expansions of it to the whole area of the scheme and to minimize the risk of salinity and sodicity problems of the water source used for irrigation. Management techniques that improve soil fertility such as crop rotations, manuring, fallow periods, proper management of crop residues, vermicomposting and leguminous cover crops and water-saving irrigation technologies suitable to the land of the area are the best options. And similar work is necessary to get additional information of the study areas because of the results of surface and profile soil and water source used for irrigation were far apart from each other.