Scholarlink

Aims <p>Chinese milk vetch (<i>Astragalus sinicus</i> L., MV) and lime are important measures for reducing the bioavailability of cadmium (Cd) in soil. However, the effects of their co-application on available Cd and Mn content in soil and rice require further investigation.</p> Methods <p>We have regularly determined the soil pH, E<sub>h</sub>, dissolved Mn and dissolved Cd concentration during decomposition period, and the available Cd and Mn content in soil at different rice growth stages, as well as the Cd and Mn content in rice plants and conducted X-ray diffraction (XRD) analysis of the soil.</p> Results <p>The results showed that in the initial stage of decomposition of MV after green manuring, accompanied by oxygen consumption during the decomposition process, soil pH increased slowly while redox potential decreased continuously. The green manuring of MV significantly increased concentration of the dissolved Mn in the soil solution, reaching a maximum of 16.53 times that of the CK treatment, suggesting that dissolved organic matter (DOM) can promote the dissolution process of Mn oxides in the soil. The determination of available Mn and available Cd contents in the soil showed that compared with the CK treatment, the redox processes of Mn oxides mediated by DOM increased the content of available Mn and decreased the content of available Cd in the soil at the tillering and maturity stages; the co-application of MV and lime could significantly reduce the Mn and Cd contents in rice straw and brown rice. Through XRD analysis, we infer that the mineral structure of Cd<sub>2</sub>Mn<sub>3</sub>O<sub>8</sub> may be formed in the soil under the treatments co-applicated by MV and lime. The formation of this new mineral structure may be related to the dissolution of soil Mn oxides by DOM from MV, and the isomorphic substitution of Mn<sub>5</sub>O<sub>8</sub> by Cd, which helps to reduce the uptake of Cd by rice. This study can provide insights for revealing the effect of MV decomposition process on Cd activity and realizing Cd reduction in rice through the complex of DOM with Mn and Cd from MV.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

The impacts of Chinese milk vetch, lime and their synergistic effect on changes of manganese and cadmium contents in soil-rice system

  • 期刊论文

  • 发表日期：

    2026年1月21日

查看全文
  • Jie Xie,
  • Yuanhua Chen,
  • Tao Yang,
  • Changxu Xu,
  • Ling Guo,
  • Yong Wang,
  • Aiqin Dong

摘要

Aims

Chinese milk vetch (Astragalus sinicus L., MV) and lime are important measures for reducing the bioavailability of cadmium (Cd) in soil. However, the effects of their co-application on available Cd and Mn content in soil and rice require further investigation.

Methods

We have regularly determined the soil pH, Eh, dissolved Mn and dissolved Cd concentration during decomposition period, and the available Cd and Mn content in soil at different rice growth stages, as well as the Cd and Mn content in rice plants and conducted X-ray diffraction (XRD) analysis of the soil.

Results

The results showed that in the initial stage of decomposition of MV after green manuring, accompanied by oxygen consumption during the decomposition process, soil pH increased slowly while redox potential decreased continuously. The green manuring of MV significantly increased concentration of the dissolved Mn in the soil solution, reaching a maximum of 16.53 times that of the CK treatment, suggesting that dissolved organic matter (DOM) can promote the dissolution process of Mn oxides in the soil. The determination of available Mn and available Cd contents in the soil showed that compared with the CK treatment, the redox processes of Mn oxides mediated by DOM increased the content of available Mn and decreased the content of available Cd in the soil at the tillering and maturity stages; the co-application of MV and lime could significantly reduce the Mn and Cd contents in rice straw and brown rice. Through XRD analysis, we infer that the mineral structure of Cd2Mn3O8 may be formed in the soil under the treatments co-applicated by MV and lime. The formation of this new mineral structure may be related to the dissolution of soil Mn oxides by DOM from MV, and the isomorphic substitution of Mn5O8 by Cd, which helps to reduce the uptake of Cd by rice. This study can provide insights for revealing the effect of MV decomposition process on Cd activity and realizing Cd reduction in rice through the complex of DOM with Mn and Cd from MV.