地学前缘 ›› 2019, Vol. 26 ›› Issue (6): 75-81.DOI: 10.13745/j.esf.sf.2019.10.5

• 污染土壤修复 • 上一篇    下一篇

基于小麦籽粒降Cd率及土壤Cd形态变化评价蚯蚓对Cd污染土壤的修复效果

刘拓,王萌,陈世宝   

  1. 中国农业科学院 农业资源与农业区划研究所, 北京 100081
  • 收稿日期:2019-06-12 修回日期:2019-09-24 出版日期:2019-11-30 发布日期:2019-11-30
  • 通讯作者: 陈世宝(1971—),男,博士,研究员,博士生导师,主要从事土壤重金属污染与防治研究。
  • 作者简介:刘拓(1992—),女,硕士,主要从事土壤重金属污染与治理方向的研究工作。E-mail:715586064@qq.com
  • 基金资助:
    国家重点研发计划项目(2016YFD0800707,2017YFD0800900);国家自然科学基金项目(41877387)

Evaluation of the efficiency of remediation of Cd contaminated soil by earthworm based on the rate of Cd reduction in wheat grain and changes in Cd bioavailability in soil experiment

LIU Tuo,WANG Meng,CHEN Shibao   

  1. Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China
  • Received:2019-06-12 Revised:2019-09-24 Online:2019-11-30 Published:2019-11-30
  • Supported by:
     

摘要: 本研究基于小麦籽粒降Cd率、土壤中Cd生物可利用态(DTPA-Cd)含量和土壤Cd移除率评价蚯蚓(赤子爱胜蚯蚓)对两种Cd污染农田土壤(河南潮土及河北褐土)的修复效果。研究结果表明:两种土壤中,添加0.5%和1.0%(蚯蚓鲜重/土壤干重)蚯蚓均能够明显降低小麦对Cd的富集,改变Cd在小麦植物器官中的分布,显著降低小麦籽粒中Cd含量(P<0.05),籽粒降Cd率达到31.1%~43.5%,促使小麦籽粒生物量增加35.5%~62.7%。添加0.5%和1.0%蚯蚓可显著降低土壤中生物可利用态Cd(DTPA-Cd)含量(P<0.05),DTPA-Cd含量下降29.1%~40.8%,有利于促进土壤中生物可利用态Cd向生物不易利用的形态转化。0.5%和1.0%蚯蚓添加使土壤中Cd移除率达到6.05%~11.88%,明显高于对照组(P<0.05),说明蚯蚓具有很好的Cd污染农田土壤修复潜力。在低Cd污染农田土壤中,蚯蚓可以降低土壤中Cd含量,减少小麦对Cd的富集,同时降低小麦籽粒Cd含量,这一研究结果对于修复低Cd污染农田土壤、保证农产品安全和实现“边生产边修复”具有重要意义。

 

关键词: Cd, 蚯蚓, 小麦籽粒降Cd率, DTPA-Cd, 土壤Cd移除率

Abstract: In this study, we evaluated the efficiency of remediation of two kinds of Cd contaminated soils (fluvo-agvic soil in Henan Province and cinnamon soil in Hebei Province) by earthworm (Eisenia fetida) in pot experiment, taking into consideration the rate of Cd reduction in wheat grain, bioavailable Cd in DTPA-extracted fraction and rate of Cd removal from soil. The results showed that Cd uptake by wheat was significantly reduced by the application of 0.5% or 1.0% earthworm(live earthworm over dry soil). Compared with control, the addition of earthworm resulted in an increase of wheat yield by 35.5%62.7%, while the rate of Cd reduction in wheat grain ranged between 31.1% and 43.5%. We believe the decreased Cd uptake and re-distribution of Cd in wheat due to earthworm were responsible for decreasing Cd content in wheat grain. The 0.5% and 1.0% earthworm could significantly reduce the soil DTPA-Cd concentration (P<0.05) by 29.1%40.8%, benefiting the transformation of Cd from bioavailable to solid forms. The removal rate of soil Cd (6.05%11.88%) was much higher than that found in the control (P<0.05), indicating earthworm has excellent potential in remediation of Cd contaminated soil. In conclusion, adding low concentration of earthworm to Cd contaminated soil played an important role in lowering Cd soil content and Cd uptake by wheat and wheat grain, which is of great significance for remediating Cd contaminated soil while ensuring the safety of agricultural products.

Key words: Cd, earthworm, rate of Cd reduction in wheat grain, DTPA-Cd, rate of Cd removal from soil

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