Characterizing the Enduring Nature of Dryland Agro-ecosystems: Irrigated and Rain-fed Land Uses in Chamo Sub Basin, Southern Ethiopia

Abstract

Characterizing soils, land use and providing suggestion for sustainable utilization of land resources in the Ethiopian Rift valley flat plain areas of Lake Chamo Sub-Basin is essential. The objectives of this study were, therefore, to characterize land use constraints and to assess the status of organic matter, macro and micro-nutrients and soil salinity for planning appropriate land management. A systematic soil survey and field observations were
made to gather information on land uses. Physiognomic vegetation classification was done in accordance with the FAO classification system, i.e. annual croppings, perennial croppings, grazing land and natural forest. A total of 120 soil samples were randomly collected from different land uses, which were prepared into 12 composites and analyzed in Ethiopia Water Works Design and Supervision Enterprise Laboratory. Organic matter, nitrogen, base saturation, exchangeable (potassium, calcium and magnesium), and phosphorus contents were low in cultivated soils compared to natural forest. Soil salinity was observed in irrigated banana and cotton field soils compared to rain-fed agriculture. Clay, nitrogen, phosphorus and potassium contents were positively correlated with organic matter and electrical conductivity. Also soluble cations and anions were varied along different land uses. Also, organic matter, exchangeable (sodium, calcium), cation exchange capacity, phosphorus and micronutrient contents
were positively correlated with soluble salts and electrical conductivity.