Soil quality in the watershed and the possible effect on the water in the storage Selova [Serbia] | Квалитет земљишта у сливу и могући утицај на воде акумулације Селова [Србија]

The ecological quality of the soil in the watershed of the storage Selova was analysed in the function of: susceptibility to acidification and indicator value of the availability of plant nutrients (nitrogen, phosphorus and base cations), and heavy metals. The analysed soils are: syrozem on serpentinite, dystric ranker on sandstone, dystric ranker on flysch, dystric ranker on dacite, eutric ranker on serpentinite, eutric ranker on schists, brownised ranker on sandstone, eutric brown soil on schists, alluvial soil. Indicator values of the availability of nitrogen range within the classes of low and very low availability, except eutric brown soil on schists, which is characterised by medium availability. The availability of phosphorus in the study soils varies widely, characterising the class of low to very high availability. Indicator values of the availability of base cations are mainly within the class of high or very high availability, except brownised ranker on sandstone and syrozem on serpentinite, which are in the class of medium availability. The susceptibility of the soil to acidification is characterised by the class of low and very low susceptibility. The mean indicator values for Zn, in all watershed soils are within the risk of deficit (less than 34.7). The values for Pb are in the class of low availability (less tha 21.0), only in the case of alluvial soil, they are in the class of high availability. The values for Cd (less than 1.8) in the study soils belong to the low class. The contents of Ni and Cr are higher than critical limits after de Vries and Bakker (1998), as well as higher than the critical concentrations according to the valid regulation on the maximum admissible concentrations of dangerous and harmful substances for agricultural soils (Official Gazette R. Serbia 11/91). The measured concentrations of Ni and Cr in alluvial soil are the consequence of sediment transport from the upper parts of the watershed with the soil formed on serpentinites. Alluvial soil covers 2% of the total area, and by the construction of the storage, the pedogenetic layer is removed by the formation of the storage shell, which means that it will not affect the quality of the water in the storage. However, the sediment transported from the upper parts of the watershed, will be deposited in the storage and it will affect the water quality. Therefore, the complete erosion control management of the upper part of the river Toplica watershed is necessary.