Copper contamination of vineyard soils from small wine producers: A case study from the Czech Republic

This work focused on evaluating metal (Cd, Cu, Pb) contamination of vineyard soils from small wine producers from the Czech Republic. Copper, as the main contaminant originating mostly from the application of Cu-pesticides, was mainly concentrated in the superficial layers and close to the treated plants, which represents its tight binding to soil organic matter and Fe-, Mn-, Al-(hydr)oxides as proved by chemical fractionation analyses. Most of the studied vineyard soils did not meet the regulatory limits for Cu in agricultural soils set by the Ministry of the Environment of the Czech Republic and the warning limits set by the European Commission (EC). The highest Cu concentrations were found in the soil from the non-active vineyard, suggesting that contamination of soils from abandoned vineyards should be investigated before changing their use in agriculture. Total Cd concentrations, resulting probably from the application of fertilisers, exceeded the Czech regulatory limits in all soils. However, when the EC regulations would be used, soils only from two vineyards would not meet the warning limits. This fact calls for a unification of the Czech and European regulations. Furthermore, standardised single-step extraction procedures, 0.01 M CaCl2; and 0.05 M EDTA (ethylenediaminetetraacetate) were carried in order to evaluate the potential availability of Cu in these soils. This study showed that the CaCl2 extraction is not suitable for predicting Cu bioavailability in slightly alkaline vineyard soils and that the EDTA extraction is more suitable for predicting the potential availability of Cu in such soils. Furthermore, the 0.05 M EDDS (ethylenediaminedisuccinate) extraction was proposed for Cu-contaminated soils as an alternative to the 0.05 M EDTA extraction procedure.