Effects of organic materials on forms and chemical properties of added exogenous cadmium in submerged fluvo-aquic soil

Effect of three organic materials (rice straw, Chinese milk vetch and pig manure) on the forms of cadmium (Cd) added and soil properties in fluvoaquic soil was studied using submerged incubation and sequential extraction. The results showed that the added organic materials increased remarkably soil solid carbon, pH value, the concentration of oxides. Accumulated SOC caused the remarkable increase of Cd bound to organic matter and the remarkable decrease of exchangeable Cd. The concentration of exchangeable Cd correlated positively with Eh, and the concentration of tightly bound organic Cd correlated negatively with Eh.