Impacts of Land Use /Land Cover Change on Soil Physicochemical Properties and Soil Carbon Stock in Lemo District, Central Ethiopia

This study investigates the impacts of land use and land cover change (LULCC) on soil physicochemical properties and soil organic carbon stock in Lemo District, Central Ethiopia. The research focuses on three dominant land use types forest land, grazing land, and cropland across three kebeles (Bellesa, Jawa, and Masibira), and considers soil samples collected at two depths (0-20 cm and 20-40 cm).

A mixed-methods approach was employed, combining household survey data from 66 purposively selected respondents with laboratory-based soil physicochemical analysis. The survey results revealed a significant expansion of cropland (mono-cropping) from the mid-1990s to 2025, driven by increasing agricultural demand and land use pressure.

Laboratory analysis showed that soil moisture content was significantly higher in forestland compared to grazing and cropland areas. Soil texture was predominantly clay loam and did not vary significantly across land use types (p > 0.05). However, key soil chemical properties-including soil pH, cation exchange capacity (CEC), available phosphorus (Av.P), organic matter (OM), organic carbon (OC), and soil organic carbon stock (SOCS)-showed significant differences (p < 0.05) among land use types at both soil depths.

Forestland consistently exhibited higher soil quality indicators, including higher pH, CEC, available phosphorus, and soil organic carbon content. Grazing land showed intermediate values, while cropland recorded the lowest levels of soil fertility indicators. Similarly, total nitrogen and soil organic carbon followed the order: cropland < grazing land < forestland, with higher concentrations observed in the topsoil layer.

Overall, the results indicate that the conversion of forest and grazing lands into cropland has led to a decline in soil physicochemical quality and soil carbon storage capacity in the study area. The findings highlight the environmental consequences of land use change and emphasize the need for sustainable land management strategies, including agroforestry practices and integrated nutrient management, to restore soil health and mitigate soil degradation.