Assessment of Soil Acidity Status and Magnitude in High Rainfall Areas of South-Western Ethiopia

ABSTRACT

Background and Objectives: In south western part of Ethiopia the soil productivity is highly in challenge due to soil acidity. This study is therefore initiated to know the extent of the soil acidity in intensively cultivated lands of kafa, Sheka and Bench-sheko zones and produce area-specific current information to motivate stakeholders to plan soil acidity amendment. Materials and Methods: Chena, Sheybench and Masha woredas were selected for respective zones. Composite samples were collected from five rural kebeles of each woreda from 15 to 20 spots at 0-20 cm depth and analyzed for pH (water), pH (kcl), N, OM, CEC, avP, exchangeable Al, exchangeable acidity and soil texture. Results: Accordingly, in Sheybench woreda, 20% of the areas showed very strong acidic (pH 4.0-5.0), while 80% showed strongly acidic (pH 5.1-5.5). Similarly, in Masha woreda, 40% of the area showed strong acidic (pH 5.1-5.5) and 60% moderately acid (pH 5.6-6.0) while Chena woreda has 20% strong acidity (pH 5.1-5.5) and 80% moderate acidity (pH 5.6-6.0). Aluminium toxicity was observed in about 40% of area. Conclusions: Therefore, lime application trials should be made and the optimum amount of lime should be recommended in the areas. In addition, crop management options should be selected to amend and improve the entire fertility of soils.