Desert soils emit greenhouse gases in minutes — even without live microbes

(Press-News.org) SDE BOKER, Israel, September 3, 2025 — A groundbreaking study from researchers at Ben-Gurion University of the Negev reveals that desert soils can emit powerful greenhouse gases within minutes of being wetted—even in the absence of microbial life.

Published by Dr. Isaac Yagle and Prof. Ilya Gelfand at BGU's Blaustein Institutes for Desert Research in Scientific Reports, the study challenges long-standing assumptions that soil microbes are solely responsible for post-rain “pulse emissions” of gases like carbon dioxide (CO₂), nitrous oxide (N₂O), and nitric oxide (NO). These gas bursts—common in drylands after rainfall—are known to contribute significantly to atmospheric warming and pollution.

Using laboratory experiments, the team compared emissions from natural and sterilized desert soils collected near the Dead Sea. The sterilization, achieved through high-dose gamma irradiation, eliminated most living organisms from the soil. Yet, even without live microbes, the sterilized soils released large quantities of N₂O and NO immediately after wetting—up to 13 times more NO and 5 times more N₂O than the live soils.

“Our results show that chemical reactions—not just biology—drive these immediate emissions, especially for nitrogen-based gases,” said Dr. Yagle. “This changes how we understand and model greenhouse gas emissions from soils in drylands.”

While CO₂ emissions remained higher in live soils due to microbial respiration, a substantial portion was still generated through non-biological processes, such as reactions involving soil carbonates and physical gas release.

These findings are particularly important as drylands expand globally due to climate change. With increasingly erratic rainfall patterns, the frequency of soil wetting and drying cycles is rising—potentially increasing the contribution of these abiotic emissions to the global greenhouse gas budget.

“Our work highlights the need to factor in abiotic processes when assessing the environmental impact of dryland soils,” added Prof. Gelfand. “Ignoring them may lead to underestimation of regional and global emissions.”

The research was supported by the Israel Science Foundation (Grant No. 305/20) and the Ministry of Science, Technology and Space of Israel (Grant No. 16797-3).

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