Abstract:
This paper present the composition of microelements in the soils in South Pirin (Southwestern Bulgaria). An analysis of the heavy metals Cu, Zn, Pb, Mn, Co, Cr and Ni has been made. The results were compared with values for the world, Europe, as well as Bulgaria. The local soil-geochemical background. The clarke of concentration (КК), the clarke of dispersion (KP) and the radial differentiation coefficient (Kp/R) have been calculated. Compared with the soils of the world, Europe and Bulgaria the study shows that there is an increased concentration (KK) of Pb and Zn, and a dispersion of Cr, Cu, Co and Mn. The radial differentiation coefficient has been used for measuring the concentration of heavy metals in different soil types: Chromic Luvisols, Cambisols – 3 soil profiles, Rendzinas and Fluvisols. In the Chromic Luvisols R shows relatively uniform movement of microelements – they accumulate from the lowest exposed soil layer to the upper one, this is most clearly distinguished by Pb. In the Rendzinas the opposite trend is observed. In the Fluvisols, the concentration of Ni and Pb in the medium soil layers is clearly visible, while the Zn – in the surface layer. The soil profiles of Cambisols are characterized by varying values of the microelements in vertical direction. But it can be concluded that the Mn is accumulated in upper layers of all 3 soil profiles.