Quantification and characterization of microplastics in farmland soils of Jiangsu Province, East China.

Abstract

The soil ecosystem plays a significant role in the dynamics of microplastics. Qualitative and quantitative analyses of microplastics in six farmland plots from the cities of Nanjing, Suzhou, and Xuzhou were conducted by using laser infrared imaging system (LDIR). The results showed that the abundance of microplastics in farmland soils in Jiangsu Province ranged from 667-9333 items/kg, and the difference between the abundance of microplastics in soils from open-field cultivation and greenhouse farming was not significant. The vertical distribution characteristics showed that the abundance of microplastic decreased significantly with the increase of soil depth. However, there was no significant difference in particle size between top soil (0-5cm) and deep soil (10-20cm). Fragments were the most common microplastic form in soil samples (94.6%), with polyvinyl chloride (PVC) being the main polymer type, followed by polyethylene terephthalate (PET). Compared with previous studies conducted in China, the abundance of microplastics in farmland soils in Jiangsu Province was at moderate level but was notably higher than other places within the Yangtze River Delta region. The conclusions drawn from this paper provided important reference data for future assessment of microplastic pollution in agricultural fields. Furthermore, they establish a fundamental groundwork for understanding the migration patterns of MPs in soil environments.