| As an important cash crop,tobacco plays an important role in economic and social development and human life.In recent years,the potential risks of discarded cigarette butts to the ecological environment have attracted much attention.Various substances in cigarette butts can enter the adjacent environment through various ways and release a series of substances to the adjacent environment under the action of rain.Soil is the main sink of cigarette butt waste,which is bound to have complex interactions with cigarette butt waste and its extract.However,our understanding of the effects of cigarette butts extract on soil microecological environment is still lacking.Therefore,in this study,different concentrations of cigarette butt extract(0,10 times diluent,50 times diluent)were set up,and the effects of the extract on the main physical and chemical properties of soil and microbial community diversity were explored by using the exogenous addition method,UPLC-MS and 16 s r RNA high-throughput sequencing technologies.This study is helpful to further clarify the impact of cigarette butts waste on soil microecological environment,and provide theoretical support for scientific assessment of potential ecological risks of cigarette butts waste.The main experimental results of this study are as follows:(1)Nicotine,cotinine and nicotinic alkaloids were detected in the soil treated with cigarette butts extract,and the contents of alkaloids detected in the high concentration extract were significantly higher than those in the low concentration extract.The content of alkaloids in soil decreased with the extension of adding time.The results indicated that cigarette butt extract could increase the content of alkaloids in soil.(2)Tobacco butt extract treatment could affect soil physical and chemical properties to a certain extent.Soil p H,organic matter,hydrolytic nitrogen,available phosphorus,and available potassium contents decreased in different degrees under high concentration treatment,and showed a downward trend with addition time.The activities of urease increased,while the activities of catalase and acid phosphatase decreased.With the extension of adding time,urease first increased and then decreased,and the activities of catalase and acid phosphatase decreased.(3)Tobacco butt extract treatment affected soil carbon and nitrogen content.The contents of soil organic carbon,soil microbial biomass nitrogen and soil microbial biomass carbon decreased in high concentration treatment.With the extension of treatment time,soil soluble organic carbon and soil microbial biomass nitrogen decreased,and soil microbial biomass carbon increased first and then decreased.(4)Tobacco butt extract changed the composition and potential function of soil microbial community.The high concentration treatment increased the relative abundance of Patescibacteria and TM7 a,but decreased the relative abundance of Proteobacteria,Acidobacteria,Methoxamine and Flavobacterium.The extract treatment significantly reduced the richness and evenness of the bacterial community,and changed the community structure.The functional prediction results showed that the potential functions of soil bacterial communities were changed to some extent by the leaching solution treatment.(5)The changes of soil microbial community were closely related to the changes of other environmental factors.RDA analysis showed that soil bacterial community could be affected by soil physical and chemical properties,soil enzyme activities and soil organic carbon,among which soil urease,soluble organic carbon,microbial biomass carbon and hydrolytic nitrogen had the greatest impact on microbial community.In conclusion,tobacco butts extract can increase the content of nicotine,the characteristic substance of tobacco in soil,affect the physical and chemical properties of soil,change the composition and potential function of microbial communities,and eventually affect the normal ecological function of soil,which may have a certain negative impact on soil health. |
PDF Full Text Request