Research progress of soil property's changes and its impacts on soil cadmium activity in flooded paddy field
Soil is the first line of defense to protect the crop safety, and the material basis for the human food quality and ecological environ-mental security. Since soil cadmium(Cd)pollution in paddy field and“Cd-polluted rice”issue become more severe in recent years, more and more researches focus on the changes of soil Cd activity and its pollution restoration. Previous results showed that submerged condition could help decrease soil Cd activity in soil and also lower the Cd content in rice. However, due to the complexity of the soil, and the diversi-ty, comprehensiveness and uncertainty of external factors, especially under submerged condition, soil properties may have complex change. On one hand, the adsorption of soil colloid, aggregate, iron/manganese oxides, organic matters and phosphate, the rise of soil pH and reduc-tion of Eh, the obstruction of oxide plaque on root surface, the coprecipitation of sulfide, the reduction of reducing bacteria, and the chelation of root exudates could lead to reduce Cd activity. On the other hand, the coordination of anions, the dissolution of iron/manganese oxides and carbonates, the adsorption of oxide plaque, the chelation of DOM, and activation of root exudates could increase Cd activity. These changes make the movement and transformation of Cd more complex, which may increase difficulty of Cd remediation in soil. In this paper, we sum-marized the changes of soil property and their effects on soil Cd activity in flooded paddy field, as well as pointed out future research direc-tions. This paper could help provide theoretical basis for the agricultural production safety and references for Cd pollution remediation in paddy field.
国家科技期刊平台
NSTL
万方数据
维普
