Studies on the transfer effect of aged polyethylene microplastics in soil-plant system

The widespread use of polyethylene (PE) agricultural films has led to a large accumulation of microplastics in soil, and the environmental effects of microplastics on soil-plants have received increasing attention. In the actual soil environment, microplastics undergo significant changes in their physicochemical properties due to aging, accompanied by complex ecological and environmental effects. However, the quantitative understanding of the environmental effects of microplastic aging in soil-plant systems is still unclear. Therefore, this study investigated the effects of aged and unaged PE microplastics on ecological functions and microplastic transfer mechanisms in soil-plant system, and confirmed the transport behavior of micrometer-sized microplastics (26 μm) within maize plants, expanding the upper size limit of existing studies on microplastic transport within plants. The accumulation of microplastics in maize was also quantitatively assessed in combination with the self-established method of Eu marked PE. The mobility ratio of microplastics from soil to roots, roots to stems, and stems to leaves was 1.07%, 0.76%, and 103.28%, respectively. This study provides a scientific understanding for the environmental effects of microplastics in soil-plants systems quantitatively. [Display omitted] •Microplastic release of endogenous organic matter in the soil environment enhances SOM accumulation.•Exposure to 0.1% Pristine PE was found to promote corn growth, while aged PE hindered its growth.•PE microplastics with a particle size of 26 μm were able to enter the corn roots to reach the stems.•Enrichment of PE microplastics in maize was root > leaf > stem.•Microplastic migration from soil to root, root to stem, and stem to leaf was 1.07%, 0.76%, and 103.28%, respectively.