生态环境学报 ›› 2023, Vol. 32 ›› Issue (3): 627-634.DOI: 10.16258/j.cnki.1674-5906.2023.03.020

• 研究论文 • 上一篇    下一篇

经济作物轮作模式下镉污染农田修复潜力

杨耀东(), 陈玉梅, 涂鹏飞, 曾清如*()   

  1. 湖南农业大学资源环境学院,湖南 长沙 410128
  • 收稿日期:2022-12-29 出版日期:2023-03-18 发布日期:2023-06-02
  • 通讯作者: *曾清如,教授,博士,主要从事农田重金属污染修复方面的研究。E-mail: qrzeng@163.com
  • 作者简介:杨耀东(1994年生)男,硕士研究生,研究方向为农田土壤重金属修复研究。E-mail: 375777498@qq.com
  • 基金资助:
    国家重点研发项目(2016YFD0800807)

Phytoremediation Potential of Economic Crop Rotation Patterns for Cadmium-polluted Farmland

YANG Yaodong(), CHEN Yumei, TU Pengfei, ZENG Qingru*()   

  1. College of Resources and Environment, Hunan Agricultural University, Changsha 410128, P. R. China
  • Received:2022-12-29 Online:2023-03-18 Published:2023-06-02

摘要:

中国农田镉(Cd)污染严重且面积广大,选择适宜的经济作物对Cd污染农田进行边生产边修复至关重要。采用大田试验,在Cd轻度污染农田种植甜高粱(Sorghum dochna)、油葵(Helianthus annuus)、油菜(Brassica napus)、白芝麻(Sesamum indicum)和亚麻(Linum usitatissimum)5种高生物量经济作物,设置甜高粱-油菜、油葵-油菜和白芝麻-亚麻3种全年轮作模式,探究其对Cd污染土壤的修复潜力。结果表明,(1)3种轮作模式中作物各部位的富集系数大于1,对Cd的富集能力较强。其中,亚麻Cd富集能力最强,各部位富集系数为1.97-9.68。白芝麻、油葵茎Cd富集能力较强,甜高粱和油菜富集能力相对较弱。(2)5种经济作物均能在Cd轻度污染农田正常生长,总生物量依次为甜高粱>油葵>油菜>白芝麻>亚麻。(3)各作物均能有效提取农田中的Cd,提取总量依次为油葵>甜高粱>亚麻>白芝麻>油菜。(4)白芝麻-亚麻、油葵-油菜和甜高粱-油菜的Cd提取总量分别为32.18、30.05、28.32 g·hm-2,对土壤的修复效率分别为3.87%、3.61%和3.40%。轮作结束后,供试土壤总Cd含量接近土壤质量标准(GB 15618—2018)。(5)在3种轮作模式中,白芝麻-亚麻轮作模式修复效率最高,预期1.62个轮作周期能将试验农田Cd降至国家标准之下。油葵-油菜、甜高粱-油菜则能在1.73和1.84个轮作周期内达成修复目标。综上所述,3种轮作模式均对Cd污染农田表现出较强修复潜力。合理利用高生物量经济作物进行轮作,能够在有效修复污染土壤的同时提升植物修复经济效益,是治理Cd污染农田可行的新思路。

关键词: 农田, 镉污染, 大生物量, 经济作物, 植物修复, 轮作

Abstract:

Serious and widespread cadmium (Cd) pollution exists in Chinese farmland. It is crucial to select appropriate economic crops for simultaneous production and remediation of Cd-polluted farmland. This study explored the remediation potential of crop rotation patterns on Cd-polluted soil by planting five high-biomass economic crops, namely sweet sorghum (Sorghum dochna), oil sunflower (Helianthus annuus), rape (Brassica napus), white sesame (Sesamum indicum), and flax (Linum usitatissimum), in mildly Cd polluted farmland through a field experiment. Three full-year crop rotation patterns were established, including sweet sorghum-rape, oil sunflower-rape, and white sesame-flax. Results showed that (1) the BCF (bioconcentration factors) of each part of the crops in the three rotation patterns was greater than 1, indicating a strong ability to accumulate Cd. Among them, flax had the strongest ability to accumulate Cd, with the BCF of each part ranged from 1.97-9.68. White sesame and oil sunflower stems also showed strong ability to accumulate Cd, while sweet sorghum and rape had weaker accumulate abilities. (2) All five economic crops were capable of normal growth in mildly Cd-polluted farmland, with the total biomass in the following order: sweet sorghum>oil sunflower>rape>white sesame>flax. (3) All crops could effectively extract Cd from farmland, with the total extraction amount in the following order: oil sunflower>sweet sorghum>flax>white sesame>rape. (4) The total Cd extraction amounts of white sesame-flax, oil sunflower-rape, and sweet sorghum-rape were 32.18 g·hm-2, 30.05 g·hm-2, and 28.32 g·hm-2, respectively, with soil remediation efficiencies of 3.87%, 3.61%, and 3.40%. After rotation, the total Cd content in the tested soil reached the soil quality standard (GB 15618—2018). (5) Among the three rotation patterns, white sesame-flax had the highest remediation efficiency, and it was expected to reduce Cd levels below the national standards after 1.62 rotation periods. Oil sunflower-rape and sweet sorghum-rape could achieve their remediation goals within 1.73 and 1.84 rotation periods, respectively. Overall, the three rotation patterns all showed strong potential for repairing Cd-polluted farmland. Reasonable crop rotation using high-biomass economic crops can effectively remediate polluted soil while improving the economic benefits of phytoremediation. This is a new feasible approach for the remediation of Cd-polluted farmland.

Key words: farmland, cadmium pollution, high biomass plant, economic crops, phytoremediation, crop rotation

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