| 温室与大田种植方式对胡萝卜生长过程中重金属吸收的影响 |
| 摘要点击 2045 全文点击 577 投稿时间：2021-06-07 修订日期：2021-07-21 |
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| 中文关键词 温室 大田 胡萝卜 重金属 生长过程 |
| 英文关键词 greenhouse open-field carrot heavy metal growth process |
| 作者 | 单位 | E-mail | | 曹春 | 西北师范大学地理与环境科学学院, 甘肃省绿洲资源环境与可持续发展重点实验室, 兰州 730070 | caochun@nwnu.edu.cn | | 任丹 | 西北师范大学地理与环境科学学院, 甘肃省绿洲资源环境与可持续发展重点实验室, 兰州 730070 | | | 吕贞英 | 西北师范大学地理与环境科学学院, 甘肃省绿洲资源环境与可持续发展重点实验室, 兰州 730070 | | | 张鹏 | 西北师范大学地理与环境科学学院, 甘肃省绿洲资源环境与可持续发展重点实验室, 兰州 730070 | | | 李锦超 | 西北师范大学地理与环境科学学院, 甘肃省绿洲资源环境与可持续发展重点实验室, 兰州 730070 | | | 陈勋文 | 南方科技大学环境科学与工程学院, 国家环境保护流域地表水-地下水污染综合防治重点实验室, 深圳 518055 | | | 王俊坚 | 南方科技大学环境科学与工程学院, 国家环境保护流域地表水-地下水污染综合防治重点实验室, 深圳 518055 | wangjj@sustech.edu.cn |
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| 中文摘要 |
| 研究不同种植方式下作物重金属吸收过程对重金属污染风险管控有重要意义.以胡萝卜为例，对比温室和大田种植方式下，3个关键生长时期6种重金属（As、Cd、Cr、Cu、Pb和Zn）的吸收转运特征，结合根际土壤理化参数，探讨种植方式对胡萝卜生物量和重金属含量随时间变化的影响并进行健康风险评价.结果表明，温室和大田种植方式具有以下共同点：①生长过程中重金属含量、生物量和吸收量均呈先升高后下降或稳定的趋势；②对As、Cd、Cr和Pb的吸收均为地上部累积型；③可食部Cd含量超标，生长期内目标风险总系数>1具有潜在的不良健康风险，主要风险由As和Cd贡献.与大田相比较，短期温室种植方式下胡萝卜成熟时间比大田提前约15 d；幼苗期和生长旺盛期时温室种植地上部As、Cd和Pb含量显著降低（P<0.05），成熟期时重金属含量（除As）无显著差异；温室种植地下部As和Cd的含量在幼苗期时降低（P<0.05），As和Cd的吸收量在0~95 d显著降低（P<0.05），其余生长阶段重金属含量和吸收量均无显著差异；通过短期种植方式的改变可以减少受污染农田蔬菜中重金属风险的可能性. |
| 英文摘要 |
| Clarifying the absorption dynamics of heavy metal(loid)s by crops under different cultivation methods is critical for risk management and control for heavy metal pollution. Here, taking carrots as an example, the pH, cation exchange capacity (CEC), and contents of heavy metals in soil and carrots were analyzed. We compared the absorption and transport characteristics of six metal(loid)s (As, Cd, Cr, Cu, Pb, and Zn) during the three key growth periods under greenhouse and open-field cultivation methods. In addition, the effects of planting methods on carrot biomass and heavy metal content over time were studied, and a health risk assessment was conducted. The results showed that the greenhouse and open-field cultivation methods had the following in common:① As the carrots continuously grew, the metal uptake and biomass in the belowground part (edible part) and the metal(loid) concentrations in the aboveground and belowground parts both showed trends of increasing first and then decreasing or stabilizing. ② The absorption of As, Cd, Cr, and Pb in carrots was mostly accumulated in the aboveground part. ③ The content of Cd in the edible part exceeded the standard, and the total target hazard quotient was>1, indicating potential adverse health risks, most of which were contributed by As and Cd. Compared to that under open-field, the short-term greenhouse cultivation had a harvest time approximately 15 d earlier. The As, Cd, and Pb concentrations in the aboveground part during the seedling and fast-growing periods were significantly lower in the greenhouse than that in the open-field (P<0.05) but did not differ between greenhouse and open-field (except As) at the mature stage. The concentrations of As and Cd in the belowground part of greenhouse carrots were lower in the greenhouse than those of carrots grown in the open-field at the seedling stage (P<0.05). The absorption of As and Cd was decreased significantly from 0 to 95 d (P<0.05), and there was no significant difference in the metal concentration and absorption in the rest of the growth stages. The bioconcentration factors (BCF) of As, Cd, and Pb in the aboveground part in all stages and those of As and Cd in the belowground part in the seedling stage were lower in the greenhouse than that in the open-field. This study emphasizes the possibility of short-term changes in cultivation mode to reduce the risks of metal(loid)s in contaminated farmland vegetables. |
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