State Key Laboratory for Conservation and Utilization of Subtropical Agri-bioresources, Guangxi Key Laboratory for Agro-Environment and Agro-Products Safety, Guangxi University, Nanning 530004, China.
Institute of Geochemistry Chinese Academy of Sciences, Guiyang 550081, China.
Ecotoxicol Environ Saf. 2023 Sep 15;263:115360. doi: 10.1016/j.ecoenv.2023.115360. Epub 2023 Aug 17.
Rice (Oryza sativa L.) consumption represents a major route of human exposure to cadmium (Cd) and arsenic (As), especially in Asia. This study investigated the effects of adding MnSO (0, 200, 400, and 800 mg kg) on the formation of soil Fe/Mn oxides and Cd and As uptake in rice. The application of MnSO reduced soil pH, increased Eh, increased the contents of Fe/Mn oxides in the soil, and decreased the total Fe and Mn contents in the porewater. It also led to lower contents of available Cd and As, higher levels of Cd and As bound to Fe/Mn oxides, and higher abundances of Thiobacillus and Syntrophobacter. Furthermore, Mn application increased the Fe and Mn contents in the root Fe/Mn plaque and decreased the grain Cd and As contents. Therefore, Mn application may modify the microbial community and porewater composition in soil, resulting in higher levels of Fe/Mn oxides in soil and Fe/Mn plaque at the root surface and in a lower accumulation of Cd and As in rice grains. Thus, Mn application can be a promising strategy for Cd and As stabilization in soils.
大米（Oryza sativa L.）的食用是人类摄入镉（Cd）和砷（As）的主要途径之一，尤其是在亚洲。本研究调查了添加 MnSO（0、200、400 和 800mg/kg）对土壤 Fe/Mn 氧化物形成以及水稻吸收 Cd 和 As 的影响。MnSO 的施用降低了土壤 pH 值，增加了 Eh 值，增加了土壤中 Fe/Mn 氧化物的含量，并降低了土壤孔隙水中的总 Fe 和 Mn 含量。这也导致了可利用 Cd 和 As 的含量降低，与 Fe/Mn 氧化物结合的 Cd 和 As 含量增加，以及 Thiobacillus 和 Syntrophobacter 的丰度增加。此外，Mn 的施用增加了根 Fe/Mn 斑块中的 Fe 和 Mn 含量，降低了稻谷中 Cd 和 As 的含量。因此，Mn 的施用可能会改变土壤中的微生物群落和孔隙水组成，导致土壤中更高水平的 Fe/Mn 氧化物和根表面的 Fe/Mn 斑块，以及稻谷中 Cd 和 As 的积累降低。因此，Mn 的施用可以作为稳定土壤中 Cd 和 As 的一种有前途的策略。
