Soil heavy metal pollution is the main risk for sustainable agriculture, especially the combination of As and Cd pollution in paddy fields which may lead to the superimposed accumulation in rice. There is an urgent need for environmental-friendly and cost-effective strategies to remediate the contamination of As and Cd in soils. In this work, a pot culture experiment was conducted in a As and Cd polluted paddy soil to explore the effects of organic fertilization (OF) and two water managements (continuous flooding, CF; intermittent irrigation, II) on the fractionation of As and Cd in soil, and the uptake of As and Cd by rice. The results showed that OF integrated with intermittent irrigation performed best in reducing the contents of As and Cd in rice grains by 58.9 % and 69.3 %, respectively, under compound pollution. The significant conversion of available As and Cd to stable species (specifically adsorbed and Fe-Mn/Al oxide bound) under OF + II were supported by the changes in an array of soil attributes such as pH, Eh, soluble Fe and dissolved organic carbon (DOC). Intermittent irrigation was more conducive to the accumulation of As outside the roots, and Fe-plaque prevented As uptake by roots and the translocation to shoots. While more accumulation of Fe-plaque along with Cd on root surface induced by continuous flooding is helpful for depressed assimilation of Cd by rice. Considering the combined contamination of As and Cd polluted in paddy soils, a management approach was proposed based on intermittent irrigation and application of organic fertilizer at the rate of 0.1 % (∼ 2.3 t/ha) in two phases (two weeks before planting or drainage). Organic fertilization will hold great promise in restoring polluted soils and maintaining soil health via suppressing the lability of heavy metals and providing nutrients.

土壤重金属污染是可持续农业的主要风险，特别是稻田As和Cd污染的组合可能导致水稻的叠加积累。迫切需要环境友好且具有成本效益的策略来修复土壤中的砷和镉污染。本工作在砷和镉污染的水稻土中进行盆栽试验，探讨有机肥（OF）和两种水分管理（连续漫水，CF；间歇灌溉，II）对砷和镉污染的影响。土壤中砷和镉的吸收以及水稻对砷和镉的吸收。结果表明，在复合污染条件下，OF结合间歇灌溉的效果最好，可分别降低稻米中As和Cd含量58.9%和69.3%。 OF + II 下有效的 As 和 Cd 显着转化为稳定物质（特定吸附和 Fe-Mn/Al 氧化物结合），这得到了一系列土壤属性（例如 pH、Eh、可溶性铁和溶解性有机碳）变化的支持。 （文档）。间歇灌溉更有利于砷在根外的积累，铁斑阻止了根对砷的吸收以及向地上部的转运。而连续淹水导致根部表面铁斑和镉的积累增多，有利于抑制水稻对镉的同化。考虑到稻田土壤中As和Cd的复合污染，提出了间歇灌溉和分两期（播种前两周或排水前两周）施有机肥0.1%（∼2.3 t/ha）的管理方法。 ）。 有机肥料通过抑制重金属的不稳定性和提供养分，在恢复污染土壤和保持土壤健康方面具有广阔的前景。