Presence of different microplastics promotes greenhouse gas emissions and alters the microbial community composition of farmland soil

Microplastics (MPs) are regarded as potential persistent organic pollutants owing to their small size and low degradability. However, the effect of MP pollution on greenhouse gas (GHG) emissions from farmland soil is yet unclear. Therefore, a series of microcosm experiments were set up using polyvinyl chloride (PVC), polypropylene (PP), polyethylene (PE), polystyrene (PS), and polyester (PET) at concentrations of 0.25 %, 2 %, and 7 % (w/w). Each treatment had three replicates. This experiment was carried out to verify the effect of MP pollution on greenhouse gas (GHG) emissions from farmland soil. The results showed that the addition of MPs significantly promoted the emissions of the three main GHGs, including nitrous oxide (N2O), carbon dioxide (CO2), and methane (CH4). Especially, PE may cause most GHG emissions which would contribute to climate warming when its pollution concentration increased. In addition, different doses and types of MPs could affect microbial community structure. These findings of this present study may provide a scientific and practical reference for the prevention and control of MPs pollution and risk assessment of global climate change caused by MPs. [Display omitted] •The presence of microplastics resulted in an increase in the contents of total phospholipid fatty acid (PLFA).•The additions of microplastics significantly promoted nitrous oxide, carbon dioxide and methane emissions.•Greenhouse gas emissions were positively and strongly correlated with the PLFA.•Polyethylene contributed the most to climate warming with increasing levels of microplastic additions.