SPATIAL VARIATION OF PHYSICAL CLAY AND ORGANIC CARBON IN THE COMPLEX OF CINNAMON FOREST SOILS (CHROMIC LUVISOLS) AND THEIR SUITABILITY FOR CULTIVATION OF VINES

Object of this study are lands in the village Balabanchevo, municipality Sungurlare, Bulgaria. The main soil type in the region is Chromic luvisols with soil profile differentiated to different degree. In the current work is studied the spatial variation of soil organic matter and physical clay content, depending on the topographical location and the degree of erosion. Studied soils are characterized by two main processes that determine the their particle size distribution - lessivage, causing accumulation of clay in subsoil and surface erosion, which is responsible for removal of relatively sandy upper layers and remaining of clayey subsurface horizons on the top. In this research is determined particle size distribution in three depths - 0-25, 25-50 and 50-75 cm and the content organic carbon in the surface horizons. Differences in clay content determined in the three studied depths are substantial and statistically significant. Differences between sampling points in respect toorganic matter content are insignificant. Relatively high levels of humus content is detected only in a small part of investigated area, where are distributed relatively dark colored soils with expressed meadow soil formation process, and in the northern and the southern parts, where to some extent more strongly is retained humus formation effect of the natural vegetation.