Abundance, spatial distribution, and characteristics of microplastics in agricultural soils and their relationship with contributing factors

Agro-ecosystem contamination with microplastics (MPs) is of great concern. However, limited research has been conducted on the agricultural soil of tropical regions. This paper investigated MPs in the agro-ecosystem of Hainan Island, China, as well as their relationships with plastic mulching, farming practices, and social and environmental factors. The concentration of MPs in the study area ranged from 2800 to 82500 particles/kg with a mean concentration of 15461.52 particles/kg. MPs with sizes between 20 and 200 mu m had the highest abundance of 57.57%, fragment (58.16%) was the most predominant shape, while black (77.76%) was the most abundant MP colour. Polyethylene (PE) (71.04%) and polypropylene (PP) (19.83%) were the main types of polymers. The mean abundance of MPs was significantly positively correlated (p < 0.01) with all sizes, tem-perature, and shapes except fibre, while weakly positively correlated with the population (p = 0.21), GDP (p = 0.33), and annual precipitation (p = 0.66). In conclusion, plastic mulching contributed to significant contami-nation of soil MPs in the study area, while environmental and social factors promoted soil MPs fragmentation. The current study results indicate serious contamination with MPs, which poses a concern regarding ecological and environmental safety.

Automated summary

This paper investigates the contamination of microplastics (MPs) in the agricultural soil of Hainan Island, China. The study finds that plastic mulching and farming practices are the main contributors to soil MPs contamination, while social and environmental factors promote the fragmentation of soil MPs. The results of this study suggest a serious contamination of MPs in the agro-ecosystem of Hainan Island, posing a concern for ecological and environmental safety.