Effects and mechanism of microplastics on organic carbon and nitrogen cycling in agricultural soil: A review

At present, microplastics (MPs) are a kind of emerging pollutants of concern in the environment, and have a wide and far‐reaching impact on terrestrial ecosystems. This article summarizes the latest research progress of the impact of MPs pollution on the biogeochemical cycle of carbon (C) and nitrogen (N), and summarizes the current situation of MPs pollution in agricultural soil. On the basis of summarizing the effects of MPs on soil physicochemical properties, soil microorganisms and soil plants and animals, this article focuses on how soil MPs affect the C and N cycles by changing these factors. MPs can alter organic matter degradation and C and N cycles by changing the soil physicochemical properties, as well as the soil microbial and enzymatic activities. MPs may alter plants' nutrient uptake processes, which in turn affects the ability of plants to photosynthesize and absorb C and N elements. MPs can affect the survival rate, the growth rate and intestinal injury of soil animals, therefore indirectly affecting the soil C and N cycles. At the same time, this article compares the different effects of conventional plastics and biodegradable plastics on soil, and looks forward to the current research deficiencies and the future research directions of ecotoxicology of MPs on C and N cycle.