Copper transfer from vineyard watershed: mineralogy and copper forms

Vineyards receive large quantities of copper, and hence, Cu-rich sediment production is expected. The objective of this work was to evaluate the transfer magnitude of copper and its chemical forms from centenary vineyards toward watershed streams making the relationship with the mineral composition of sediments. Five representative rainfall-runoff events were chosen to collect sediments downstream from centenarian vineyard area (VY), and riparian forest (RF: control) and in the watershed stream (US: upstream—control, and DS: downstream). A rich mineralogical assemblage was found in VY and DS sites; the mineralogy was composed of: mica, kaolinite, illite, rutile, hematite, quartz, calcite, magnesite, albite, and anorthite, and Cu-bearing minerals. Centenarian vineyard delivered Cu-rich sediments in particulate, soluble, and available Cu forms. However, in the majority of the downstream sediments, the Cu was transferred in a particulate form. Here, we evidenced that the Cu-transfer mechanism was strongly associated with the mineral sediment composition, since Cu-bearing minerals were found in vineyard and downstream sediments. Furthermore, grape production remains a complex activity, in which traditional practices, such as Cu-fungicide application, should be revisited to maintain soil health and environmental quality.