Factors influencing the availability of copper in australian vineyard soils

The regular use of copper-based fungicides in vineyards results in an accumulation of copper (Cu) in the surface soils which may be harmful to soil organisms and plants and have implications for the long-term management of affected land. This study investigated the factors (e.g. soil characteristics) influencing the availability of Cu in vineyard soils from 10 different regions of Australia. Concentrations of 0.01 M calcium chloride extractable Cu measured in surface soils collected from 98 different vineyards ranged from <0.1 to 0.94 mg/kg and accounted for 0.10 to 1.03% of the total Cu concentrations in the soils. Differences in the calcium chloride extractable Cu concentrations were related to the total Cu concentration of the soil. The extractable Cu was also related to soil properties, including pH, cation exchange capacity, exchangeable K, clay, silt, and calcium carbonate. The information generated from this study may prove useful in devising strategies to reduce the availability and toxicity of Cu in agricultural soils.