摘要
为明确蚯蚓活动对不同酸碱性土壤中铬(Cr)赋存和细菌群落的影响,采用控制试验探究了赤子爱胜蚓(Eisenia fetida)对不同酸碱性(酸性pH 5.88、中性pH7.55、碱性pH 8.97)、不同Cr含量(15 mg kg^(-1)和50 mg kg^(-1))土壤中Cr赋存形态和细菌群落的影响。结果表明:接种蚯蚓后,土壤pH值向中性转变,低Cr含量土壤的pH值变化量大于高Cr含量土壤;相比于酸性和碱性土壤,接种蚯蚓后中性土壤中的Cr去除率最高,低Cr含量中性土壤的Cr去除率达62.74%,高Cr含量中性土壤的Cr去除率达37.51%;接种蚯蚓后,土壤中酸可提取态Cr的含量显著增加,残渣态Cr的含量显著降低;接种蚯蚓提高了酸性土壤中变形菌门的丰度、降低了放线菌门的丰度,提高了中性和碱性土壤中放线菌门的丰度,降低了变形菌门和拟杆菌门的丰度,显著提高了土壤细菌群落的丰度(Chao指数和ACE指数),但显著降低了其多样性(Shannon指数)。综上,蚯蚓通过摄食和被动扩散作用对中性土壤中Cr的富集、移除效果优于对酸性和碱性土壤,接种蚯蚓能够有效提升土壤中Cr的生物有效性,改变土壤的细菌群落结构。
A control experiment was conducted to explore the effects of earthworm(Eisenia fetida)activity on Cr occurrence and bacterial communities in soils with different acid-base(acidic, neutral, and alkaline with pH 5.88, 7.55, and 8.97, respectively)and Cr(15 mg·kg^(-1) and 50 mg·kg^(-1))levels. The results showed that after the addition of earthworms to acidic soils, the soil pH significantly increased. In neutral and alkaline soils, the soil pH was significantly reduced after consumption by earthworms. Consumption of soil by earthworms led to the pH becoming neutral, and the pH value of low Cr content soil was higher than that of high Cr content soil. Among the acid-base soils,the removal rate of Cr by earthworms was the highest in neutral soil. In neutral soil with a low Cr content, the Cr removal rate was 62.74%,whereas the Cr removal rate was 37.51% in neutral soil with a high Cr content. Earthworm biomass decreased significantly after consuming Cr-contaminated soil with different acidities and alkalinities, and the higher the soil Cr concentration, the greater was the Cr enrichment in earthworms. After consumption by earthworms, the content of acid-extractable Cr in the soil increased significantly at all pH values, and the residual Cr content was reduced dramatically;earthworms had the best effect on activating Cr in acidic soil. After consumption by earthworms, the abundance of Proteobacteria was increased in acidic soils, whereas that of Actinomycetes reduced. In contrast, the abundance of Actinomycetes increased in neutral and alkaline soils and that of Proteobacteria and Bacteroidetes reduced. Furthermore, the abundance of soil bacterial communities(Chao and ACE indices) was significantly increased and the diversity(Shannon index)significantly reduced. In summary, earthworms enriched and removed Cr in neutral soils through feeding and passive diffusion, and these effects were better than those in acidic and alkaline soils. Incorporating earthworms into the soil can effectively improve the bioavailability
作者
王浩羽
韦杰
孙进宇
宋言
顾强
宓文海
居静
赵海涛
封克
WANG Haoyu;WEI Jie;SUN Jinyu;SONG Yan;GU Qiang;MI Wenhai;JU Jing;ZHAO Haitao;FENG Ke(College of Environmental Science and Engineering,Yangzhou University,Yangzhou 225127,China;Jiangsu Yangzhou Agricultural Environmental Safety Technology Service Center,Yangzhou 225127,China;Key Laboratory of Cultivated Land Quality Monitoring and Evaluation,Ministry of Agriculture and Rural Affairs,Yangzhou 225127,China)
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2022年第7期1472-1482,共11页
Journal of Agro-Environment Science
基金
国家自然科学基金项目(31000939)。
关键词
赤子爱胜蚓
土壤
pH值
铬形态
细菌群落
Eisenia fetida
soil
pH value
chromium form
bacterial community
