By Abbas Nazil
A new study has revealed that microplastics not only reduce soil fertility but also increase the release of nitrous oxide, a greenhouse gas nearly 300 times more potent than carbon dioxide.
The research, published in Environmental Science & Technology, shows that more than 90 percent of plastic waste ends up in soils, where it breaks down into invisible particles that disrupt microbial communities, alter soil chemistry, and worsen climate change.
Unlike previous studies that tested one type of plastic at a time, researchers led by Yi-Fei Wang and Dong Zhu of the Chinese Academy of Sciences examined the combined effects of different plastics.
They conducted a 40-day microcosm experiment using soil mixed with six types of plastics, including polyethylene terephthalate (PET) and polyvinyl chloride (PVC), and compared them to control samples without plastics.
The results revealed significant shifts in soil health as microplastic diversity increased.
Soils became more alkaline, carbon levels rose, and enzyme activities linked to nutrient cycling changed.
The most critical finding was the boost in bacterial genes responsible for denitrification, the process by which microbes convert plant nutrients into nitrogen gas.
This process not only strips soil of fertility but also leads to the emission of nitrous oxide.
The researchers identified Rhodocyclaceae bacteria as the main driver of this accelerated nitrogen loss.
According to the study, this effect could reduce crop yields, disrupt nutrient cycles, and exacerbate climate change if not addressed.
The findings underscore the urgent need to incorporate microplastic diversity into soil management strategies and highlight the hidden but severe risks of plastic contamination on agricultural systems.
The authors stress that reducing plastic pollution and improving soil health practices are essential to safeguard food production and mitigate environmental damage.