INVESTIGATING CHANGES IN SOME SOIL PROPERTIES DEPENDING ON LAND USE AND DEPTH LAYERS: A CASE STUDY FOR THE GODRAHAV CREEK WATERSHED IN ARTVIN, TURKEY

The Eastern Black Sea Region is characterized by mountainous and steep terrain, limiting agricultural activities. This, in turn, has been causing the natural lands of mostly forests and grasslands in the region to be converted to other uses, mostly agriculture as an alternative income for the local people. However, it is well known that such conversions negatively affect all the natural resources including soil properties. Therefore, in this study, changes in some soil parameters in the forest and the neighboring agriculture (converted from the forest) lands within the watershed of the Godrahav Creek Watershed were investigated with respect to current land use type and soil depth. For this purpose, a total of 36 soil samples based on land use types (forestland, agriculture) and soil depth (0-10 cm and 10-20 cm) were taken to be analyzed for texture, permeability, bulk density, organic matter (OM), pH. Differences and relations among these properties were statistically examined using the analysis of variance analyses (ANOVA). It was determined that the most of the soil characteristics analyzed were significantly different between the lands of forest and agriculture in the study area. For example, as expected, the amount of OM was significantly higher in forestlands with 6.71% than the agricultural land with 5.50% while the pH was increased from 5.51 to 6.88 after conversion. In addition, bulk density was also increased from 1.07 gr/cm(3) in forests to 1.23 gr/cm(3) in agriculture areas whereas better permeability was found for forestlands (302.32 mm/hr) than agricultural lands (110.96 mm/hr).