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农学学报 ›› 2024, Vol. 14 ›› Issue (3): 53-57.doi: 10.11923/j.issn.2095-4050.cjas2023-0071

• 土壤肥料 资源环境 生态 • 上一篇    下一篇

污染农田茭白镉积累特点及茭白安全生产的土壤镉阈值

丁利群1(), 陈宇航2, 章明奎2()   

  1. 1 开化县农业农村局,浙江开化 321300
    2 浙江大学环境与资源学院,杭州 310058
  • 收稿日期:2023-03-11 修回日期:2023-06-01 出版日期:2024-03-16 发布日期:2024-03-16
  • 通讯作者:
    章明奎,男,1964年出生,浙江绍兴人,教授,博士,主要从事土壤质量管理方面的研究。通信地址:310058 浙江省杭州市西湖区余杭塘路866号 浙江大学紫金港校区环境与资源学院,E-mail:
  • 作者简介:

    丁利群,男,1971年出生,浙江开化人,高级农艺师,本科,主要从事土壤与肥料技术推广研究。通信地址:324300 浙江省开化县城关镇望江弄2号 开化县农业农村局,E-mail:

  • 基金资助:
    国家自然科学基金“长期全年淹水集约种植对水耕人为土性态演变和物质循环及生态功能的影响”(41977001)

Cd Accumulation Characteristics of Zizania latifolia in Polluted Farmland and Safety Threshold of Cd in Producing Areas

DING Liqun1(), CHEN Yuhang2, ZHANG Mingkui2()   

  1. 1 Agricultural and Rural Bureau of Kaihua County, Kaihua 321300, Zhejiang, China
    2 College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, Zhejiang, China
  • Received:2023-03-11 Revised:2023-06-01 Online:2024-03-16 Published:2024-03-16

摘要:

为了解茭白对土壤镉的吸收与积累特点,从浙江省镉污染地区的茭白产地同时采集了57对茭白不同器官样(根、短缩茎、叶、肉质茎)与耕层土样,分析了茭白不同器官中镉的积累规律及其与土壤镉含量的关系。结果表明:茭白不同器官中镉含量由高至低依次为:根>短缩茎>叶>肉质茎,根、短缩茎、叶、肉质茎中镉的平均富集系数分别为1.553、0.675、0.222、0.077。茭白各器官中镉的积累与土壤镉污染水平呈正相关,相关系数由高至低顺次为根>短缩茎>叶>肉质茎;各器官中镉的富集系数随土壤pH的增加而下降。茭白根部积累的镉有较高比例以氧化铁结合态存在,表明茭白根表积累的氧化铁可阻减镉进入茭白地上部分。初步分析表明,在土壤pH≤5.5、5.5<pH≤6.5和6.5<pH≤7.5时,土壤全镉含量分别约为1.00、1.25、2.00 mg/kg以下时,肉质茎中镉含量均在0.050 mg/kg以下,可达到安全生产的要求。研究认为,茭白可食部位(肉质茎)具有镉低积累特点,可替代水稻种植在中轻度污染的农田中。

关键词: 茭白, 镉, 积累特点, 安全生产

Abstract:

To understand the characteristics of Cd uptake and accumulation by Zizania latifolia, 57 pairs of Zizania latifolia organs (roots, short stems, leaves and fleshy stems) and topsoil samples were collected from Cd-polluted fields in Zhejiang Province to study the accumulation of Cd in different organs of Zizania latifolia and its relationship with soil Cd content. The results showed that Cd accumulated in different organs of Zizania latifolia decreased in the order of root>short stem>leaf>fleshy stem. The average enrichment coefficients of Cd in root, short stem, leaf and fleshy stem were 1.553, 0.675, 0.222 and 0.077, respectively. Correlation analysis showed that Cd accumulated in different organs of Zizania latifolia was positively correlated with total soil Cd, and their correlation coefficients with various organs from high to low was root>short stem>leaf>fleshy stem. The enrichment coefficients of Cd in various organs of Zizania latifolia decreased with the increase of soil pH value. A high proportion of Cd in roots was found in oxide iron-bound form, which indicated that the accumulated iron oxides on the root surface of Zizania latifolia could prevent Cd from entering into its aboveground part. The preliminary analysis showed that when the soil pH≤5.5, 5.5<pH≤6.5, 6.5<pH≤7.5, and corresponding total Cd content in the soils was below 1.00, 1.25 and 2.00 mg/kg, respectively, the Cd content in the fleshy stem of Zizania latifolia was below 0.050 mg/kg, which could meet the requirements of safe production. The study showed that the edible part (fleshy stem) of Zizania latifolia had the characteristics of low Cd accumulation, which could be used as a substitute for rice in the farmland with medium and light Cd pollution.

Key words: Zizania latifolia, Cd, accumulation characteristics, safety production