Soil amendment to remediate copper contaminated soils

Copper contamination to agricultural soils has been accelerated due to its wide and repeated use in agriculture and horticulture as fertilizers or fungicides to protect vines, citrus trees, and other fruit crops against fungus diseases. Laboratory incubation and field survey were conducted to understand the mechanisms of Cu inactivation by Ca@water plant res iduals (Ca@WTRs containing mainly CaCO 3 and minor CaO) and to estimate the optimal rate of Ca@WTRs fo r remediation of Cu@contaminated soils. The results indicate that Ca@WTRs can effectively raise soil pH and convert water soluble and exchangeable Cu to more stable oxides@bound and residual Cu frac tions in the soils. A pH value of 6.5 was found to divide the high (pH 6.5) availability of Cu in the soils. Based on this criterion and the response curve of pH to Ca@WTRs application rate, the optimal rates of Ca@WTRs can be estimated for different Cu@contaminated soils.