Influence of copper and Fusarium culmorum on metal solubility and wheat uptake in alluvial-meadow soil.

Copper adsorption and bioavailability to whole wheat plants in a slightly alkaline Alluvial-meadow soil (pH 7.4) contaminated with Cu (250-1500 mgkg-1) and inoculated or uninoculated with Fusarium Culmorum was studied in a laboratory (Cu adsorption experiment) and greenhouse (pollution and inoculation) experiments. Availability was assessed by using two different extract solutions: 0.01 MCaCl2 and 1M NH4NO3, both of which adequately and signifi cantly predicted copper uptake by whole wheat plants. Copper adsorption in the studied soil conformed to a straight line in both inoculated and uninoculated soil. The distribution coeffi cients Kd corresponded to a higher solution concentration range than found for unpolluted soils and refl ected the higher uptake of Cu by wheat plants. Cu concentrations observed for wheat plants increased with increasing total Cu contents (250–1500 ppm) in the Alluvial-meadow soil and were accompanied with enhanced levels of nitrogen and potassium. High concentrations in whole wheat plants exceeding normal range of copper in unpolluted soils were achieved in the greenhouse experiment. The Fusarium Culmorum inoculation of the soil lead to a decrease in total extracted copper in extract solutions, but did not infl uence the short term Cu adsorption nor did it decrease Cu uptake by plants. The highest concentrations of copper (1500 mg/kg) lead to soil acidifi cation and mobilization of bioavailable copper species in the wheat plants.