Abstract:Soil moisture changes can significantly affect soil properties and lead to the change of soil heavy metal availability. In this study, the effects of moisture and drying process on soil heavy metal availability were studied by investigating Zn, Cd, Cu, Ni concentrations represented by DGT and in soil solution. The results showed that soil drying process could decrease DOC concentration of soil solution and change soil heavy metal availability. Zn, Cd, Cu, Ni availability evaluated by DGT and concentrations of Cu, Ni in soil solution decreased with the soil water contend decreasing during soil drying processes; compared with the soil with long dry duration, the dry soil subjected with dry-wet cycle decreased or significantly decreased in heavy metal availability. Compared with the method evaluating metal availability by determining metal in the soil solution, DGT can reflect on the effects of soil moisture on metal buffer supply ability from the solid metal, and give much better evaluation to soil metal. In agricultural production, appropriate water management can be used to reduce the availability of heavy metal, thus alleviate the toxicity of heavy metal.