| 有机肥对土壤-水稻系统砷镉富集转运的影响及机制 |
| 摘要点击 1251 全文点击 32 投稿时间：2025-03-08 修订日期：2025-06-12 |
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| 中文关键词 砷镉 水稻土 有机肥 根表铁膜 微生物群落 |
| 英文关键词 As-Cd paddy soil organic fertilizer root iron plaque microbial community |
| DOI 10.13227/j.hjkx.202503085 |
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| 中文摘要 |
| 为探讨有机肥同时调控稻田土壤砷（As）和镉（Cd）有效性及其在水稻中的富集作用，选择湖南省某As-Cd复合污染稻田开展田间试验，研究了不同用量商品有机肥（OF）和紫云英（MV）施用对土壤理化性质、根表铁膜、土壤微生物群落结构和水稻富集转运As-Cd的影响. 结果表明，OF处理提高土壤pH值和有效态As-Cd含量，高量MV处理下有效态Cd含量显著减少12.0%~12.9% （P<0.05）. 有机肥处理促进铁膜形成并增加其中As-Cd含量. 与对照相比，OF和MV施用下As根部/铁膜（As-TFR/F）和Cd糙米/茎叶（Cd-TFL/S）转运系数明显减少，糙米As和Cd含量分别显著降低10.9%~17.4%和14.3%~47.6%，无机As和Cd含量均低于《食品安全国家标准 食品中污染物限量》（GB 2762-2022）规定限值. 糙米As与铁膜中Fe含量呈显著负相关，与As-TFR/F呈显著正相关；糙米Cd与铁膜Cd含量呈显著负相关，与Cd-TFL/S呈显著正相关（P<0.05），表明有机肥通过抑制水稻根部吸收As，促进铁膜固持Cd并抑制其从茎叶向糙米转运从而降低糙米As-Cd含量. 冗余分析表明，糙米As和Cd含量均与绿弯菌门丰度呈正相关，有机肥可通过减少绿弯菌门丰度同时降低糙米As-Cd含量. 研究结果为有机肥料调控稻米As-Cd含量提供技术支持. |
| 英文摘要 |
| A field experiment of paddy soil co-contaminated by As-Cd in Hunan Province was conducted to study the role of organic fertilizers in simultaneously regulating As and Cd uptake by rice grain. This research investigated the effects of different application levels of commercial organic fertilizer (OF) and milk vetch (MV) on soil physicochemical properties, root iron plaque, rhizosphere soil microbial community structure, and content and translocation of As-Cd in rice. The results showed that soil pH and the availability of As and Cd in soil from the OF treatment was improved, whereas the available Cd content from a high level of MV addition treatment was significantly reduced by 12.0%-12.9% (P<0.05). Organic fertilizer treatments enhanced iron plaque formation and content of As and Cd in the iron plaque. The As and Cd content in brown rice from the OF and MV treatment was significantly decreased by 10.9%-17.4% and 14.3%-47.6%, respectively, compared with that in the control treatment. The translocation factors of As (As-TFR/F) and Cd (Cd-TFL/S) from organic fertilizer treatments were significantly decreased (P<0.05), and the content of inorganic As and Cd in brown rice were below the limits listed in the National Food Safety Standard for Contaminants in Food (GB 2762-2022). Brown rice As content was significantly negatively correlated with Fe content in iron plaque and significantly positively correlated with As-TFR/F, whereas rice Cd content was significantly negatively correlated with Cd content in iron plaque and significantly positively correlated with Cd-TFL/S (P<0.05). These results indicated that organic fertilizer application reduced As-Cd content in brown rice through inhibiting As uptake by roots, as well as promoting Cd immobilization in iron plaque and inhibiting its transport from shoot to grain. RDA analysis revealed that brown rice As and Cd content was positively correlated with relative abundance of Chloroflexi, suggesting that organic fertilizer application simultaneously reduced As-Cd accumulation in brown rice through decreasing Chloroflexi abundance. These findings provide a technical base for organic fertilizer regulation of As-Cd content in rice grain. |
