Land use change and its effect on selected soil properties in the northwest highlands of Ethiopia

Evidence on land use/land cover (LULC) change and its effect on soil properties are important for sustainable land management interventions. Hence, this study was conducted to analyze LULC change over a period of 31 years and to evaluate the effects of land use on soil properties in the Ganzer watershed, northwest Ethiopia. Landsat satellite images (1988, 2002 and 2019) were used as a source of information image analysis and LULC classification were done using ERDAS imagine 2010 software. About 24 composite soil samples were collected from four land use types (natural forest, plantation forest, cultivated and grazing lands) at two soil depths (0-20 and 20-40 cm) to determine soil properties. Standard soil analytical methods were used in carrying out soil analysis. The result revealed that the study site has undergone extensive land use changes where cultivated and grazing lands declined by 5.4% and 22.6%, respectively. However, the settlement and forest lands increased by 7.9% and 20%, respectively (1988-2019). The soil physicochemical properties differed significantly (p < 0.05) across the land use types and with soil depth. Higher contents of clay, pH, organic carbon (OC), total nitrogen (TN), available phosphorus (AP), exchangeable bases (Ca, Mg, K, Na) and CEC were recorded in the natural forest than in the other land use types. Similarly, pH, clay, BD and exchangeable bases increased with an increase in soil depth across all land use types. Generally, LULC change in the study area showed a significant increase in settlement and forest lands due to population pressure and expansion of eucalyptus plantation forests. These inappropriate land use changes have a negative effect on soil properties. Therefore, an appropriate and effective intervention in the land use systems should be implemented to amend soil properties.