A Review for Effect of Organic Substances on the Availability of Cadmium in Soils
有机物质对土壤镉有效性的影响研究综述

Low-molecular-weight organic acids (LMWOAs) and humic acids have great effects on the availability of cadmium in the soils. LMWOAs, which was excreted by the plant roots, can increase the extractability, transportation and bio-availability of soil cadmium while the organic acids with higher molecular weight such as EDTA prohibits its adsorption by plant. Humic acids promote the solubility of soil cadmium. Depending on the different fractions of humic acids and environmental factors, humic acids can increase or decrease the availability of cadmium. Therefore, it is necessary to study further the factors which immobilize the soil cadmium so as to prevent soil cadmium activity through organic matter.