Study on soil quality in different functional zones of Sofia region

The present study deals with examining the condition of urban soils and their potential to deliver soil-related regulating ecosystem services concerning the level of anthropogenic pressure in different functional zones of Sofia, Bulgaria. Analyses of data for selected characteristics of superficial 0-10 cm soil layer of urban soils were performed. Soils were sampled from 30 experimental plots within a geo-referred network covering urban and peri-urban territories. The concentrations of heavy metals Cu, Zn, Pb and Fe were analysed to determine the level of pollution, while soil pH, cation-exchange capacity (CEC), total carbon and total nitrogen content were used as indicators for assessing the regulating ecosystem service “soil quality”. The results demonstrate the differences in the potential of four functional zones – green zones, industrial zones, residential zones and zones for urban agriculture, to regulate and maintain “soil quality”. The purpose of the assessment is to outline the zones with the potential for implicating mitigation measures in urban and peri-urban zones, based on maps of soil quality, which contributes to focusing more attention on the protection and restoration of urban soils, to reduce soil pollution and to increase the reuse of urban soils.