Soil Bunds Effect on Soil Properties under Different Topographies of Southwest Ethiopia

Soil erosion is a major environmental problem affecting development endeavors. Physical soil and water conservation (SWC) measures such as soil bunds are implemented to mitigate soil erosion. However, information on the effects of soil bunds on soil fertility is limited. This study aimed to evaluate soil quality in fields with soil bunds and with no soil bunds in steep, middle and lower sloping cultivated lands as well as spatial variation of soil properties in between bunds in southwest Ethiopia. About 7-15 years old bunds and nearby cultivated fields lacking bunds were assessed. From 0 cm-20 cm soil depth, 36 soil samples were collected. Soil texture, soil organic carbon (SOC), total nitrogen (Ntot) and exchangeable potassium (Kexch) were analyzed. Soil bunds showed significantly (p<0.0.5) greater clay but less sand than adjacent no-bund fields. In steep, middle, and lower slopes, concentrations of SOC and Kexch were greater in fields with soil bunds than without. Lower slope fields showed greater clay, SOC and nutrients than steep slopes. In between soil bunds, soil was more fertile at bunds than below the bunds. In Fanta watershed, soil bunds are a vital conservation measure to retain soil fertility in cultivated mountainous areas.