MICROPLASTICS: SOIL POLLUTION RESEARCH PT.3
There are very few studies on the impacts of microplastics in terrestrial ecosystems, especially in agricultural ecosystems. Microplastics in agricultural ecosystems affect not only the microbial biomass of the soil, microbial activity, and functional diversity but also the cycle of processing essential nutrients in plants, which can have an indirect effect on plant growth and crop yield.
Microplastics that persist in the soil for a long period are more likely to form nano plastics, which migrate and accumulate in plants before being ingested by the food chain, eventually exposing humans and causing damage to the ecological environment. Soil plants are an essential component of terrestrial ecosystems, and their growth is influenced by this soil environment.
Microplastics can play a significant role in the growth of soil plants. The study of the cellular structure of tobacco reveals that nano plastics can enter tobacco cells through endocytosis, implying that very small plastics can be absorbed into the plant's body through its rhizosphere.
According to Asli and Neumann (2009) and Ma et al. (2010), the accumulation of microplastics in plants can affect the uptake and transport of nutrients and other important digestible products by blocking cell wall pores or cell connections. Qi et al. (2018) conducted an experiment in a pot using LDPE and a biodegradable plastic film based on starch as research materials, mixing 1% plastic residue with soil during wheat growth.
The plastic residues were found to have an impact both on the above-ground and below-ground parts. When Oenanthe Javanica plants were exposed to different sizes of particles (50, 500, 4800 nm) and concentrations (103-105 particles/mL), the rate of seed germination was significantly inhibited, especially with the impact of larger-sized microplastics.
However, Judy et al. (2019) reported insignificant effects of microplastics on seed germination and wheat biomass. Current research mainly focuses on the external effects of microplastics on soil plants and is limited to certain species. The toxicological effects of microplastics on soil plants, as well as their interaction mechanisms, have not yet been fully understood. The pathways of microplastic entry into plants, as well as analysis and detection methods, are still being optimized. Therefore, the generalizability of the results does not apply to all plant species.