Determining the effects of land use on soil erodibility in the Mediterranean highland regions of Turkey: a case study of the Korsulu stream watershed

Sustainable soil management can be concisely defined as using soil without impairing soil function. It has become crucial due to soil degradation, especially that caused by soil erosion, throughout the world. In this context, this study aimed to determine the erodibility and some soil properties to evaluate the actual state of soil resources in a watershed located in the Mediterranean highland of Turkey. A total of 180, 90 disturbed and 90 undisturbed, soil samples were collected from different land-use types, namely, forest, pasture, and agriculture. Erodibility and soil properties such as texture, soil organic matter, permeability, particle density, bulk density, porosity, pH, electrical conductivity, field capacity, permanent wilting point, and water holding capacity were determined. A soil erodibility map was also produced using ArcGIS software. According to the results, the average soil organic matter was 6.27%, 4.56%, and 2.05% in forest, pasture, and agriculture, respectively, and the differences among land-use types were significantly different. The average erodibility (USLE-K) value was 0.09 for forest, while it was 0.12 and 0.22 for pasture and agriculture, respectively. The difference between agriculture and forest and pasture was statistically significant, while no statistically significant difference was found between forest and pasture in the study area. Forest was included in the slightly erodible class, while pasture and agriculture were included in the moderately and highly erodible classes, respectively. The erodibility map also revealed that a major part of the study area is susceptible to erosion. The study clearly showed that sustainable soil management is a necessity, especially for agricultural lands.