Copper and zinc fractions in vineyard soils in the Middle Western of Santa Catarina

The aim of this study was to assess the migration and modification of Cu and Zn fractions in vineyard soils. In October 2010 in Agua Doce, SC, Brazil, three vineyards of different age and a natural field area were selected. Stratified soil samples were collected, which were dried, ground up and subjected to analysis of chemical attributes, and chemical fractionation of Cu and Zn was done by the EDTA and 3050B method of the USEPA. The Cu and Zn were accumulated in the uppermost surface layers of the vineyard soils, in greatest quantity in the oldest vineyard. The majority of the Cu and the Zn in the vineyard soils was distributed in the residual fraction, which has low geochemical mobility, but, in the uppermost soil layers of the oldest vineyard, there was an increase of the Cu content bound to soil organic matter and, in the deepest soil layers, of Cu bound to minerals. Most of the Zn in the vineyard soil was distributed in the residual fraction and bound to the minerals, which have low mobility and toxicity potential for the plants.