Viruses help cut farm greenhouse gas emissions by targeting soil microbes

Viruses, often seen only as disease-causing agents, may hold surprising potential as natural allies in the fight against climate change. A new study published in Nitrogen Cycling reveals that soil viruses can reduce nitrous oxide (N2O) emissions by selectively infecting the microbes responsible for producing this potent greenhouse gas.

Nitrous oxide is nearly 300 times more powerful than carbon dioxide at trapping heat in the atmosphere. It is largely released from agricultural soils through a process called denitrification, in which soil microbes convert excess fertilizer into nitrogen gases. Until now, most efforts to curb these emissions have focused on fertilizer management and microbial communities, with little attention to the role of soil viruses.

Researchers from the Chinese Academy of Sciences conducted controlled experiments to test how different concentrations of viruses affect soil emissions. They added live virus extracts to farm soil collected from the North China Plain, a region known for high fertilizer use and significant nitrogen losses. Using gas measurements and genetic sequencing, they discovered that viral addition reduced N2O emissions by up to 20 percent compared with untreated soil.

The reason, the team found, lies in the way viruses interact with denitrifying microbes. Viral infection suppressed major bacterial groups that carry the genes needed to produce nitrous oxide. In particular, the study highlighted that viruses targeted members of Pseudomonadota, an abundant group of soil bacteria, leading to lower production of greenhouse gases. Network analysis also showed that soils with higher virus levels developed more complex virus–microbe interactions, suggesting that viral infections actively reshaped the microbial community.

“Our findings show that viruses are not just passive residents of the soil but active players that can alter greenhouse gas emissions,” said senior author Shuping Qin. “This opens the door to considering virus-based approaches for climate-smart agriculture.”

While the study was carried out under controlled laboratory conditions, the authors emphasize that the findings could have wide-reaching implications. If similar results hold in farm fields, viral regulation of soil microbes might offer a new tool to help agriculture reduce its environmental footprint. The researchers suggest that phage-based applications could one day be developed to target high-emission microbes, though more studies are needed to test feasibility, safety, and stability in real-world soils.

By highlighting an overlooked component of soil ecosystems, this research points to the hidden potential of viruses in climate mitigation strategies. Far from being only destructive, viruses in the soil may play a critical role in supporting sustainable food production and protecting the planet.

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Journal Reference: Song W, Yao J, Fu Y, Qin S. 2025. Viruses mitigate soil nitrogen loss and N₂O emissions during denitrification by selectively infecting denitrifiers. Nitrogen Cycling 1: e004 https://www.maxapress.com/article/doi/10.48130/nc-0025-0002  

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About Nitrogen Cycling:
Nitrogen Cycling is a multidisciplinary platform for communicating advances in fundamental and applied research on the nitrogen cycle. It is dedicated to serving as an innovative, efficient, and professional platform for researchers in the field of nitrogen cycling worldwide to deliver findings from this rapidly expanding field of science.

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