Size effects of microplastics on competition between crop and weed via soil microbes
Year: 2025
Type: article
Abstract: Microplastics (MPs) are widespread contaminants in agroecosystems, with potential implications for soil microbial communities, plant growth, and crop-weed interactions. This study investigates how MPs of different particle sizes influence crop-weed competition by altering soil microbial communities. Through a controlled greenhouse experiment, we examined the effects of 50 μm and 500 μm polyethylene (PE) MPs on competition between Eruca sativa (crop) and Amaranthus retroflexus (weed). We specifically analyzed shifts in bacterial and fungal community composition, microbial functional groups, and interkingdom microbial networks. Our results indicate that MPs negatively affect plant growth, with larger MPs (500 μm) increasing the competitive advantage of weeds over crops. MPs also alter soil microbial dynamics, leading to a shift in bacterial-fungal interactions from bacterial to fungal dominance with increasing PE particle size. Specifically, smaller MPs (50 μm) promoted bacterial functional groups associated with carbon cycling, whereas larger MPs increased the relative abundance of fungal plant pathogens. Additionally, larger MPs significantly reduced crop biomass, likely due to nutrient cycling disruptions and increased pathogen pressure, ultimately favoring weed competitiveness. This study provides new insights into how MPs pollution influences soil microbial dynamics and crop-weed interactions in agroecosystems.
Authors: Yanmei Fu, Yong Yu, Guanghui Xu, Matthias C. Rillig
Language: English
Subfield: Pollution
Field: Environmental Science
Domain: Physical Sciences
SDGs: Life on land, Zero hunger
Open Access status: gold
Estimated APC paid: $3,650
Awards: G2281972039, G4285554459, G5767990913
OpenAlex ID: W4413873458