Impacts of Nano- and Microplastic Contamination on Soil Organisms and Soil–Plant Systems

Microplastic (MPL) and nanoplastic (NPL) contamination in soils is widespread, impacting soil invertebrates, microbial communities, and soil–plant systems. Here, we compiled the information from 100 research articles from 2018 onwards to enhance and synthesize the status quo of MPLs’ and NPLs’ impacts on such groups. The effects of these pollutants depend on multiple factors, including polymer composition, size, shape, concentration, and aging processes. Research on soil invertebrates has focused on earthworms and some studies on nematodes and collembolans, but studies are still limited to other groups, such as mites, millipedes, and insect larvae. Beyond soil invertebrates, plastics are also altering microbial communities at the soil–plastic interface, fostering the development of specialized microbial assemblages and shifting microbial functions in ways that remain poorly understood. Research has largely centered on bacterial interactions with MPLs, leaving understudied fungi, protists, and other soil microorganisms. Furthermore, MPLs and NPLs also interact with terrestrial plants, and their harmful effects, such as adsorption, uptake, translocation, and pathogen vectors, raise public awareness. Given the complexity of these interactions, well-replicated experiments and community- and ecosystem-level studies employing objective-driven technologies can provide insights into how MPLs and NPLs influence microbial and faunal diversity, functional traits, and soil ecosystem stability.