Quantitative Distribution and Quantized Ecological Threat of Microplastics in Farmland: East China as an Example

Abstract

The occurrence of microplastics (MPs) in farmlands was correlated to the reduction of crop yield and food safety issues. In this study, a field study was carried out to explore the occurrence of MPs in East China. The effect of farmland types and cultivation years on the accumulation of MPs was clarified for further understanding of the mechanism of the accumulation of MPs in farmlands. Moreover, the key factor of the health of farmland soil and crop yield was recognized for the in-depth understanding of the ecological threat of MPs. MPs abundance in vegetable fields was significantly higher than that in orchards. The cropping modes might be the critical factor for the accumulation of MPs in different types of farmlands. pH acted as the driving force for all biological indicators while TS and Sand served as the key factor for microbial diversity and metabolic activity. Furthermore, SOM was the critical factor for the soil enzyme activity. MPs only played a role in soil enzyme activity. Besides, the MPs abundance served as one of the critical factors for rice yield (31.74% of relative importance), and MPs pollution might lead to a significant reduction of the rice yield.

Keywords: Abundance of microplastics, Cultivation years, Relative importance, Crop yield