5种除草剂对旱地红壤细菌群落的影响研究

Effects of Five Herbicides on Bacterial Communities in Upland Red Soils

  • 摘要: 除草剂除了控制农田杂草,也可能对土壤中的非靶标生物产生作用,但目前对不同类型除草剂的生态效应鲜有比较研究。该研究针对长期施化肥(CF)和长期有机无机肥配施(OM)的2种不同旱地农田红壤,选择常用的5种除草剂(土壤处理型:乙草胺、仲丁灵、甲咪唑烟酸;茎叶处理型:乙羧氟草醚、精喹禾灵)加入土壤微宇宙并进行培养。采用16S rRNA基因高通量测序方法对不同暴露时间的土壤细菌群落进行分析,结果表明,除草剂对旱地红壤细菌群落的影响存在差异。乙草胺、仲丁灵和甲咪唑烟酸的效应较为类似,可改变细菌群落多样性与组成,导致绿弯菌门纤线绳菌科(Ktedonobacteraceae)相对富集,共现网络中的负相关关系比例增加。相比之下,乙羧氟草醚、精喹禾灵对土壤细菌的影响较小。这些区别可能与土壤处理型和茎叶处理型除草剂在土壤中的活性有关。暴露时间、长期施肥不同导致的土壤性质如有机质含量差异也是影响仲丁灵、精喹禾灵、甲咪唑烟酸等微生物生态效应的重要因素。研究揭示了常见土壤处理型与茎叶处理型除草剂的土壤生态效应及其影响因素,将为红壤地区旱地农田除草剂的安全使用提供科学依据。

     

    Abstract: Herbicides are widely used to control weeds in cropland. Meanwhile, they may have consequences on non-target organisms in soil. However, the ecological effects of different types of herbicides are still poorly understood and less compared. This study explored the impacts of herbicides on bacterial communities in differentially fertilized upland red soil, which is the dominant soil type in southern China. Five commonly used herbicides (pre-emergence: acetochlor, butralin, imazameth; post-emergence: fluoroglycofen-ethyl and quizalofop-p-ethyl) were added to soil microcosms. The soil bacterial communities were analyzed by high-throughput sequencing of the 16S rRNA genes. The results show varied effects associated with individual herbicides on the bacterial communities in these upland red soils. The responses of soil bacteria to acetochlor, butralin and imazameth were similar, which altered the diversity and composition of bacterial communities, leading to the relative enrichment of Ktedonobacteraceae of Chloroflexi, as well as the increase in negative correlations in the co-occurrence network. In contrast, fluoroglycofen-ethyl and quizalofop-p-ethyl were less influential. These differences may be related to the activity difference between pre-emergence and post-emergence herbicides. Exposure time, as well as soil properties caused by long-term application of either chemical fertilizers (CF) or combined mineral and organic fertilizers (OM), were also identified as important factors influencing the ecological effects of herbicides such as butralin, quizalofop-p-ethyl, and imazameth. These findings reveal the complexity of the soil ecological effects of different herbicides, and will provide a scientific basis for the safe application of herbicides in upland red soil.

     

/

返回文章
返回