| 秸秆离田对土壤Cd生物有效性及水稻Cd积累的影响 |
| 摘要点击 1366 全文点击 399 投稿时间：2022-07-01 修订日期：2022-09-29 |
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| 中文关键词 秸秆离田 水稻 Cd污染土壤 有效态 Cd赋存形态 溶解性有机碳(DOC) |
| 英文关键词 straw removal measure rice Cd-contaminated soil bioavailability Cd fraction in soil dissolved organic carbon (DOC) |
| 作者 | 单位 | E-mail | | 王子钰 | 中南林业科技大学环境科学与工程学院, 长沙 410004 | wangziyu199521@163.com | | 周航 | 中南林业科技大学环境科学与工程学院, 长沙 410004
稻米品质安全控制湖南省工程实验室, 长沙 410004 | zhouhang4607@163.com | | 周坤华 | 中南林业科技大学环境科学与工程学院, 长沙 410004 | | | 谭文韬 | 中南林业科技大学环境科学与工程学院, 长沙 410004 | | | 蒋毅 | 中南林业科技大学环境科学与工程学院, 长沙 410004 | | | 唐棋 | 中南林业科技大学环境科学与工程学院, 长沙 410004 | | | 伍港繁 | 中南林业科技大学环境科学与工程学院, 长沙 410004 | | | 辜娇峰 | 中南林业科技大学环境科学与工程学院, 长沙 410004
稻米品质安全控制湖南省工程实验室, 长沙 410004
国家环境保护重金属污染监测重点实验室, 长沙 410019 | | | 曾鹏 | 中南林业科技大学环境科学与工程学院, 长沙 410004
稻米品质安全控制湖南省工程实验室, 长沙 410004 | | | 廖柏寒 | 中南林业科技大学环境科学与工程学院, 长沙 410004
稻米品质安全控制湖南省工程实验室, 长沙 410004 | |
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| 中文摘要 |
| 通过选取湖南省宁乡市某轻度Cd污染稻田开展连续两季水稻秸秆离田田间试验，研究秸秆离田措施对轻度Cd污染稻田土壤Cd有效性及水稻对Cd吸收累积的影响.结果表明：①连续两季秸秆离田有效提高了土壤pH值，降低土壤有机质和根际土壤Cd含量；T1~T4处理使土壤pH值提升0.04~0.58个单位，有机质含量降低了0.68%~25.87%，根际土壤Cd含量降低了3.76%~12.78%.②连续两季秸秆离田能降低酸可提取态和可氧化态Cd占比，使残渣态Cd占比上升；同时秸秆离田处理降低了根际土壤Cd的生物有效性，使根际土壤TCLP、DTPA和CaCl2提取态Cd含量均显著降低.③水稻秸秆离田可显著降低土壤孔隙水中DOC和Cd浓度，连续两季秸秆离田处理下（T1~T4）土壤孔隙水中Cd浓度分别降低了4.54%~40.00%和2.75%~67.34%，说明DOC是影响土壤孔隙水中Cd浓度的关键因素之一.④连续两季秸秆离田各处理（T1~T4）降低了水稻各部位对Cd的吸收累积，其中秸秆和根系全部离田处理（T4）下，2020年晚稻和2021年早稻糙米Cd含量分别降低了18.52%和39.69%.因此，在Cd污染农田实行秸秆全部或部分离田是一项降低稻米Cd含量超标风险的有力措施. |
| 英文摘要 |
| A field experiment was conducted in a lightly Cd-contaminated rice field in Ningxiang City, Hunan Province, to study the effects of straw removal measures on the soil Cd bioavailability and rice Cd accumulation. The results showed that:① two consecutive seasons of straw removal measures (T1-T4 treatments) effectively increased soil pH by 0.04-0.58 units, reduced soil organic matter by 0.68%-25.87%, and reduced the Cd content of rhizosphere soil by 3.76%-12.78%. ② The proportions of Cd in the acid-extractable fraction and oxidizable fraction decreased, and the proportion of Cd in the residual fraction increased. Furthermore, straw removal measures significantly reduced the bioavailability of Cd in rhizosphere soil, and the Cd contents in TCLP, DTPA, and CaCl2 extracts all significantly decreased compared with those in CK. ③ The straw removal measure could significantly reduce the content of DOC and Cd in soil pore water; and the contents of Cd in soil pore water decreased by 4.54%-40.00% and 2.75%-67.34% under the straw removal measure (T1-T4) for two consecutive seasons, respectively, indicating that DOC was one of the key factors affecting the content of Cd in soil pore water. ④ Two consecutive straw removal measures (T1-T4) reduced the accumulation of Cd in different rice tissues, among which, under the treatment of all straw and root removal (T4), the Cd contents of brown rice in late rice planting in 2020 and early rice planting in 2021 decreased by 18.52% and 39.69%, respectively. Therefore, full or partial removal of straw in Cd-contaminated rice fields is a powerful measure to reduce the risk of exceeding Cd levels in brown rice. |
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