中文关键词
石灰有机物料理化因素Cd形态水稻Cd | 英文关键词limeorganic mattersphysical and chemical factorsfractions of CdCd in rice plants |
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| 中文摘要 |
| 以重庆市某县Cd污染稻田为研究对象，通过原位小区试验，探讨石灰和有机物料配施对土壤Cd形态及水稻植株Cd吸收和分配的影响，研究对土壤Cd形态转化的影响机制.结果发现，修复剂的施用能显著提升土壤pH、OM含量和CEC，CEC与OM含量呈极显著正相关，与pH显著正相关；pH和CEC是导致土壤Cd由酸可提取态向可还原态、可氧化态和残渣态转化的主要因素；随着修复剂的施用，B1~B6处理酸提取态Cd占比下降22.92%~31.25%，导致水稻植株Cd积累量也不同程度下降，表现为CK（对照）≫B6（石灰+秸秆）≈B4（石灰+生物炭）≈B3（石灰+活化腐殖酸） > B2（石灰+腐质有机肥）≈B1（石灰） > B5（石灰+油枯）.B1~B6处理糙米Cd含量下降9.90%~20.79%，但均高于国家限量标准（GB 2762-2017）；精加工后B1~B6处理精米Cd含量均符合国家限量标准.综合结果表明，复配型修复技术对当地实现农业污染土壤安全利用和粮食安全输出具有一定参考意义，B5处理（石灰+油枯）是修复酸性Cd污染稻田的最佳配施措施，酸提取态Cd占比下降31.25%，水稻植株Cd总积累量下降33.32%，而精米Cd含量减少42.17%. |
| 英文摘要 |
| Using an in-situ experiment in Cd contaminated paddy fields in Chongqing, the absorption and distribution of Cd in rice plants was examined following the combined application of lime and organic matter, and the mechanisms driving changes in Cd fractions in soil were also studied. The results showed that pH, OM content, and CEC in the soil were significantly enhanced, and OM and CEC were significantly positively correlated, as pH showed a significant positive correlation; pH and CEC was mainly associated with a change in Cd from the acidic extractable fraction to the reducible, oxidable, and residual fractions. The percentage of acidic extractable Cd dropped by 22.92%-31.25% with the application of the amendments, thus reducing the accumulation of Cd in rice plants in the followed order:CK (control group)≫B6 (lime and maize straw)≈B4 (lime and biochar)≈B3 (lime and activated humic acidic fertilizer) > B2 (lime and humic acidic fertilizer)≈B1 (lime) > B5 (lime and oil cake). On the other hand, for both the treatments and control conditions (CK), the Cd content of brown rice was higher than Chinese standard (GB 2762-2017), while that of polished (white) rice was lower than the Chinese standard after treatment. Overall, treatment using all of the remediation agents offers some benefit for the safe utilization of agricultural contaminated soil and safe food production. The combined application of lime and oil cake proved the best measure for treating Cd contaminated acidic rice fields, yielding a reduction in acidic extractable Cd (31.25%), a reduction in the Cd content of rice plants (33.32%), and the lowest Cd content (0.13 mg·kg-1) in polished rice (a 42.17% compared to the control). |
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