Effects of land use type on hydro-physical properties of soils in the torul dam basin-gumushane, Turkey

Abstract

The soils in the Eastern Black Sea Region of Turkey are under serious degradation and erosion due to misused of land, over grazing and intensive agricultural activities. In this study, some soil properties and the effects of land use types on the erodibility indices were investigated for the Torul Dam located on the Harşit River, which is in the Backward of Black Sea region in Turkey. By selective sampling method, samples were collected from three different sites used for agriculture, forest and bare space amount of soil samples from each site are 16, 26 and 18 respectively. Soil samples were gathered according to depth levels of 0-20cm and 20-50cm for each sample plot, and a total of 280 soil samples disturbed and undisturbed soil samples were collected from four sites at each of the three different land-use types. Sixty sample plots were selected from frontier lands with the same aspect in the same altitude zone and the same parent material from which soil develops. In soil samples, analyses such as particle size distribution (sand, silt, clay), soil organic matter (SOM), dispersion ratio (DR), erosion ratio (ER), colloid-moisture equivalent ratio (C-MER), clay ratio (CR), water holding capacity (WHC), hydraulic conductivity (HC), bulk density (BD), total porosity (TP), available water capacity (AWC), soil pH and total lime (CaCO3) were performed for each soil sample. The analysis of variance was performed in order to test whether the obtained results showed differences according to interaction to land use regime and soil depth. The results show that significant differences the average erodibility indices (DR, p<0.05, ER, C-MER, CR, p<0.001), sand (p<0.01), silt, clay, CaCO3, SOM (p<0.001) and soil properties such as BD, TP, WHC, HC, pH (p<0.001) vary according to land use regime. The results show that significant differences the average DR, BD, TP (p<0.05) and SOM (p<0.01) vary according to interaction to land use regime and soil depth. As a result, it was determined that soils of all three land use types in the dam basin are strongly susceptible to erosion. Therefore, it is necessary to make a plan for planting the bare areas without effecting the water production in a negative way.