Abundance and occurrence characteristics of microplastics in soil of film-mulched tobacco fields in Guizhou
The research on microplastics (MPs) in farmland soil is in its initial stage. Plastic film mulching is considered to be the main source of MPs in farmland soil,but the study on MPs from plastic film residue in soil is still relatively scarce. In this study,soil samples were collected from film-mulched tobacco fields in the main to-bacco-producing areas of Guizhou Province,the flotation-electrostatic method was used to separate and extracte MPs from the soil,and their abundance and occurrence characteristics were analyzed. The results showed that the abundance of MPs in the soils of film-mulched tobacco fields ranged from 4325 to 7949 Piece·kg-1,and the par-ticle size of MPs decreased with the increase of mulching time. The abundance of MPs with particle size of 0.25-0.85 mm in soil was high,with the highest proportion of 98.86% in Jingzhou Village,Qianxi County,where the film-mulching period was longest. Comparing with other study areas,it was found that the abundance of MPs was relatively high in the film-mulched tobacco fields in Guizhou,and there was a potential ecological risk. The results of this study will further enrich the data of MPs in farmland soil in China,which can provide a reference for further research and pollution prevention of MPs in soils.