Microplastics in plant-microbes-soil system: A review on recent studies

Microplastics (MPs) and nanoplastics (NPs) have been widely studied, mostly focusing on the methods of separation, detection, and adsorption or the ecological effects in aquatic ecosystems. When different sources and types of MPs/NPs enter the soil, they can affect the biogeochemical cycle in terms of the direct impacts on soil physicochemical properties and soil organisms, and the indirect impact on soil biota through changes in soil material cycling. To date, a few studies have focused on the effects of MPs/NPs on soil ecosystems, including soil properties, microbial communities, soil fauna, and plants, as well as the potential or affirmed correlations among them. In this review, we summarized the recent literature on soil MPs/NPs focusing on their types, sources, separation, and ecological impacts on soil properties, microbes, and plants. We attempted to establish an overall relationship between MPs/NPs and soil plant system. Based on existing studies, we also highlight the research gaps and propose several directions for future studies.