Redox conditions in paddy soils may vary as they are submerged and drained during rice growth. This change may bring about reductive dissolution of iron (Fe) oxides and subsequent formation of secondary Fe-bearing m...Redox conditions in paddy soils may vary as they are submerged and drained during rice growth. This change may bring about reductive dissolution of iron (Fe) oxides and subsequent formation of secondary Fe-bearing minerals in rice paddies. The mobility and bioavailability of metal contaminants such as cadmium (Cd) in paddy soils are closely related to the chemical behaviors of Fe. Therefore, in this paper, advances in the study of paddy Fe redox transformations and their effects on Cd availability to rice are briefly reviewed. Current concepts presented in this review include the forms of Fe in paddy soils, the reactions involved in Fe oxidation-reduction, chemical factors affecting Fe redox processes, Cd availability to rice and the impacts of Fe transformation on Cd uptake and translocation in rice. Prospects for future research in this area are also discussed.展开更多
基金Financial supports from the National Natural Science Foundation of China (Grant No. 30700479), Research Fund for the Doctoral Program of Higher Education of China (Nos. 20090097110035 and 20110097110004), Research Fund of State Key Laboratory of Soil and Sustainable Agriculture, Nanjing Institute of Soil Science, Chinese Academy of Science (No. Y052010019) and National Undergraduate Student Innovational Research Training Program (No. 091030726) are greatly acknowledged. The authors would like to thank Professor William Hendershot of McGill University for the editing of this manuscript.
文摘Redox conditions in paddy soils may vary as they are submerged and drained during rice growth. This change may bring about reductive dissolution of iron (Fe) oxides and subsequent formation of secondary Fe-bearing minerals in rice paddies. The mobility and bioavailability of metal contaminants such as cadmium (Cd) in paddy soils are closely related to the chemical behaviors of Fe. Therefore, in this paper, advances in the study of paddy Fe redox transformations and their effects on Cd availability to rice are briefly reviewed. Current concepts presented in this review include the forms of Fe in paddy soils, the reactions involved in Fe oxidation-reduction, chemical factors affecting Fe redox processes, Cd availability to rice and the impacts of Fe transformation on Cd uptake and translocation in rice. Prospects for future research in this area are also discussed.