Copper content and distribution in vineyard soils of central Serbia

Abstract

This research studied the copper content of vineyard soils as affected by the long-term use of copper-based fungicides. The soil samples were taken from individual vineyards located in the central region of Serbia, from two depths: 0-30 and 30-60 cm. At the same time, at each site, control samples were collected from a nearby forest in order to determine the background concentrations. The pseudototal (CuT) and available (CuEDTA) copper content were analysed in 60 soil samples in total, 46 of which represented vineyard soils and 14 control samples. The maximum value of copper was 200.1 mg/kg of pseudototal and 82.1 mg/kg of available copper. Comparison of the copper content in vineyards to the background concentrations of control samples clearly confirmed anthropogenic influence. Out of 46 vineyard soil samples, about one half (22 of them) had the CuT concentration above the critical level of 60 mg/kg. Eleven samples had the pseudototal content over the MAC of 100 mg/kg. Anthropogenic influence was also confirmed on the basis of copper bioavailability and copper distribution along the soil profile. Available content of over 50 mg/kg was found in 8 out of 46 analysed samples of vineyard soils. According to the percentage contribution of available CuEDTA to pseudototalCuT, half of the samples were above 36%, which is potentially phytotoxic. The concentration of copper was the highest in the surface layer in the vineyard soil samples. A check of the background Cu levels has shown that the distribution of CuT and CuEDTA is uniform throughout the soil profile. Data from some of the analysed plots indicate that the process of erosion is under way at the site. The soil on lower-lying terrain has been found to be more exposed to copper pollution than the soil of higher terrain. Since copper at the surveyed sites is very persistent and accumulates in a short period of time, focus should be placed on the preventive measures of reducing the use of copper-based fungicides to an optimal level.