Cu and Zn in soil physical fractions of vineyards in southern Brazil

Abstract

The cultivation of vines in regions with high rainfall, as in southern Brazil, involves the use of fungicides to control foliar fungal diseases. These fungicides normally contain copper (Cu) and zinc (Zn) in their composition, promoting the accumulation of these metals in the soil. The objective of this work was to evaluate the distribution of Cu and Zn in the granulometric physical fractions in soils from vineyards in southern Brazil. Soil samples (0-5 and 10-20 cm) were collected in two areas of vineyards and a forest area in three regions of southern Brazil, one in Santa Catarina and two in Rio Grande do Sul states. Samples from the 0-5 cm layer were fractionated into > 50 μm and < 50 μm. In the soil samples and in the fractions, the total contents of Cu and Zn were determined by X-ray fluorescence. Vineyard areas in southern Brazil show great variations in total Cu and Zn contents, due to different soil characteristics and cultivation history. For Cu, there is no distinction between the fractions, but Zn accumulates, preferentially, in the fraction <50 μm.