What does this research mean for the field?

Fulvic acid amendment in flooded paddy soils reduces Cadmium (Cd) availability while increasing Arsenic (As) mobility, a process driven by the co-variation of dissolved organic matter (DOM) components and iron (Fe) fraction changes. Novelty: ClaimNovelty.INCREMENTAL. Consensus alignment: ConsensusAlignment.NEUTRAL.

What question did this study set out to answer?

This research aims to investigate the relationships between dissolved organic matter, iron fractions, and the mobility of cadmium and arsenic in flooded paddy soils amended with fulvic acid.

May 16, 2026

Co-variation among DOM components, Fe fractions, and Cd / As mobility under fulvic acid amendment in flooded paddy soils.

Key Points

This research aims to investigate the relationships between dissolved organic matter, iron fractions, and the mobility of cadmium and arsenic in flooded paddy soils amended with fulvic acid.
Applied fulvic acid amendment in flooded paddy soils
Monitored changes in cadmium and arsenic mobility and iron fractions
Utilized Random Forest and Structural Equation Modeling for analysis
Fulvic acid amendment markedly increased total dissolved organic matter content, with humic-like components rising by 0.9-1.5-fold and protein-like components by 1.3-3.7-fold.
Cadmium was redistributed from exchangeable forms to more stable forms, reducing overall availability, while arsenic mobility increased.
Iron oxides showed significant changes, with decreases in Fed by 6.2-11.5% and increases in Feo by 6.2-25.9%.

Abstract

-As (9.5-28.1%). These were accompanied by a redistribution of Cd from the exchangeable fraction (EX-Cd) toward more stable forms (CA-Cd, WOM-Cd, and OX-Cd), and by a reduction in Fe-As together with increases in AE-As and Al-As fractions. Total DOM content increased markedly upon FA addition, with substantial increases in humic-like (C1 and C2, 0.9-1.5-fold) and protein-like (C3, 1.3-3.7-fold) components. Furthermore, decreases in Fed (6.2-11.5%) and increases in Feo (6.2-25.9%) under reduction conditions were accelerated by FA amendment. Random Forest (RF) and Structural Equation Modeling (SEM) analysis consistently identified DOM components and Fe fractions as the dominant predictors of Cd / As availability. The relationships among DOM components, Fe oxide fractions, and metal availability suggest that the co-variation of DOM components and Fe fraction changes may contribute to reduced Cd availability. In contrast, the increased As mobility may be associated with Fe oxide reduction, DOM competitive interaction, and possible As valence transformation. These findings provide association-based evidence linking DOM composition, Fe fraction changes, and Cd / As behavior in flooded paddy soil.

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Cite This Study

Li et al. (Wed,) studied this question.

synapsesocial.com/papers/6a080b17a487c87a6a40d200 https://doi.org/https://doi.org/10.1016/j.ecoenv.2026.120256

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