Professor Huang Qiaoyun's team at Huazhong Agricultural University recently published a research paper titled "Microplastics trigger soil dissolved organic carbon and nutrient turnover by strengthening microbial network connectivity and cross-trophic interactions" in the journal Environmental Science & Technology.

The study elucidates the cascade mechanism through which microplastic pollution in agricultural soil drives nutrient cycling by reshaping the structure of the microbial food network, providing methodological and theoretical support for understanding the environmental ecological effects of microplastic pollution in agricultural soil.

By combining microcosm simulations with soil sterilization experiments, researchers tracked the succession of microbial communities and soil nutrient turnover dynamics in typical agricultural soil contaminated with microplastics. They found that microplastic input led to a significant increase in soil soluble organic carbon content, enrichment of humic acid components, and a sharp decrease in nitrate nitrogen content, triggering a microplastic-induced soil priming effect.

Regulation of soil carbon and nitrogen cycling processes by multitrophic interactions in microbial food networks under microplastic pollution. [Photo/news.hzau.edu.cn]

Despite variations in the responses of bacteria, fungi, and protozoa in the microbial food network to different types and concentrations of microplastics, microplastics consistently shaped a tightly connected and complexly interactive microbial multi-trophic level "social network", increasing network connectivity and cross-trophic level interaction intensity by a factor of two to five compared to uncontaminated soil.

Protozoa act as key connecting hubs in the network, playing important roles in linking multiple trophic level modules and enhancing network connectivity. The impact of microplastics on carbon and nitrogen in sterilized soil was almost eliminated, further confirming the central driving role of microbial processes.