Microplastics in Agricultural Soils: Sources, Fate, and Interactions with Other Contaminants

Microplastics (MPs) are recognized as emerging soil contaminants. However, the potential risks of MPs to agroecosystems have not been fully revealed, especially the compound toxic effects of MPs with co-existing organic or inorganic pollutants (OPs/IPs) in agricultural fields. In this study, we quantified the contributions of different agronomic practices to the sources of MPs in soil and highlighted the important influences of long-term tillage and fertilization on the migration and aging of MPs in agricultural fields. In addition, the antagonistic and synergistic interactions between MPs and OPs/IPs in soil were explored. We emphasized that the degree of adsorption of MPs and soil particles to OPs/IPs is a key determinant of the co-toxicity of those contaminants in soil. Finally, several directions for future research are proposed, and these knowledge gaps provide an important basis for understanding the contamination process of MPs in agricultural soils.