Mobility and Phytoavailability of Arsenic and Cadmium at the Soil-corn Interface in Sewage Irrigation Polluted Farmlands Northwest, China
Abstract The activity of heavy metals in farmland soil and the safety of food crops after long-term sewage irrigation are the premise of sustainable development of agriculture. The major pollutants of arsenic (As) and cadmium (Cd) in farmland-corn system affected by sewage irrigation for 40 years were studied. The results showed that although the content of total As in soil was high, the absorption and transport of total As by corn were relatively small, and As could not migrate down the soil profile. On the contrary, Cd mainly exists in the form of exchangeable and carbonate-bound which has strong fluidity. By optimizing the method of investigating the bioavailability of pollutants and systematically and comprehensively studying the migration law of pollutants in various parts of maize tissues, it is concluded that Cd still has high activity after stopping sewage irrigation, and the development process of maize roots has a significant relationship between the contact of heavy metals in the surface soil and the enrichment of heavy metals in the upper part of corn tissues (p < 0.01). Therefore, this study can increase the understanding of the migration law of pollutants in corn, and provide a basis for remediation of contaminated soil in local and other areas.