ECO-CHEMICAL CHARACTERISATION OF FLUVISOL OF VELIKA MORAVA RIVER VALLEY (SERBIA) BASED ON THE PHYSICO-CHEMICAL PARAMETERS AND DISTRIBUTION OF HEAVY METALS

Eco-chemical characteristics of the soil from the Velika Morava River valley were examined by analysis of 27 samples of agricultural soil of fluvisol type. The main physico-chemical parameters (pH, carbonate, humus, total nitrogen, available potassium and phosphorus contents), and total and available contents of heavy metals (Pb, Zn, Cu and Cd) were determined. The aim of this research was to have an insight into the current eco-chemical state in the examined agricultural region, by detection of the main substrates of heavy metals, as well as by analysis of their possible origin. In all the examined samples, total Zn, Cu and Cd contents, and in most of the examined samples, total contents of Pb, obtained by sequential extraction, were below maximum allowed concentrations (MAC) for agricultural soils. The increased content of total Pb (104.28-161.03 mg/kg) in some of the examined samples was probably caused by anthropogenic activity. Results of the sequential extraction, as well as the extraction with diethylene triamine pentaacetic acid (DTPA), used for extraction of available metals, indicated the anthropogenic sources of Pb, Cu and Cd, whereas Zn was most often of geochemical, native origin. The obtained results were subject to correlation and factor analysis. Both methods confirmed the correlation between Zn and Cd, leading to the conclusion that a part of Zn was also of anthropogenic origin. Factor analysis brought together total contents of Zn and Cd, and pH-value of the soil, and indicated the possibility of its easy mobilisation at slight changes in soil acidity.