Impact of soil structure and texture on occurrence of microplastics in agricultural soils of karst areas

Xiuyuan Yang; Zhenming Zhang; Xuetao Guo

doi:10.1016/j.scitotenv.2023.166189

Impact of soil structure and texture on occurrence of microplastics in agricultural soils of karst areas

Sci Total Environ. 2023 Dec 1:902:166189. doi: 10.1016/j.scitotenv.2023.166189. Epub 2023 Aug 9.

Authors

Xiuyuan Yang¹, Zhenming Zhang², Xuetao Guo³

Affiliations

¹ College of Resources and Environmental Engineering, Guizhou University, Guiyang 550025, Guizhou, China.
² College of Resources and Environmental Engineering, Guizhou University, Guiyang 550025, Guizhou, China; Key Laboratory of Kast Georesources and Environment, Ministry of Education, Guizhou University, Guiyang 550025, China; Guizhou Karst Environmental Ecosystems Observation and Research Station, Ministry of Education, Guiyang 550025, China. Electronic address: zhangzm@gzu.edu.cn.
³ College of Natural Resources and Environment, Northwest A & F University, Yangling 712100, China. Electronic address: guoxuetao2005@nwsuaf.edu.cn.

PMID: 37567305
DOI: 10.1016/j.scitotenv.2023.166189

Abstract

The impact of microplastics (MPs) on soil ecosystems has attracted widespread attention; however, the effects of soil structure and texture on the occurrence of MPs are not fully understood. In this study, we investigated the effects of soil structure and texture on the abundance of MPs and their potential mechanisms in agricultural soils of karst areas in Guizhou, China. The results showed the average abundance of MPs was 2948 items/kg. The soil texture in the study area can be categorized into seven types such as powdered-light clay, the range of total soil porosity was 39.05-69.22 % and the range of soil bulk density was 0.66-1.51 g/cm³. Soils with a powdered-light clay, low soil porosity, and low soil bulk density showed higher MPs pollution. The percentage of pellet MPs in agricultural soils with a powdered-light clay was 84 %, which was higher than that of the other soil textures. The direct effects of soil texture, soil porosity, and soil bulk density on MPs abundance were much lower than the indirect effects, with soil texture having the highest effect on MPs abundance. We speculated that karst geology may affect the accumulation and distribution of MPs in soil by affecting soil texture and structure, which, in turn, affects the fragmentation and migration of MPs. These findings will help to better understand the mechanisms of soil MPs pollution and provide a scientific basis for the development of relevant control strategies.

Keywords: Farmland; Karst; Microplastics; Soil structure; Soil texture.