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The sharp redox gradient at soil-water interfaces (SWI) plays a key role in controlling arsenic (As) translocation and transformation in paddy soils. When Eh drops, As is released to porewater from solid iron (Fe) and manganese (Mn) minerals and reduced to arsenite. However, the coupling or decoupling processes operating within the redox gradient at the SWI in flooded paddy soils remain poorly constrained due to the lack of direct evidence. In this paper, we reported the mm-scale mapping of Fe, As and other associated elements across the redox gradient in the SWI of five different paddy soils. The results showed a strong positive linear relationship between dissolved Fe, Mn, As, and phosphorus (P) in 4 out of the 5 paddy soils, indicating the general coupling of these elements. However, decoupling of Fe, Mn and As was observed in one of the paddy soils. In this soil, distinct releasing profiles of Mn, As and Fe …