Ozonated irrigation in vineyards: limited effects on soil bacterial and fungal microbiota

Ozone is a volatile compound with strong oxidizing and disinfectant properties, and its use in crops such as grapevines has been proposed as an alternative to abusive pesticide application. Although its disinfectant efficacy has been demonstrated in barrels and grape berries, and its effects on vine physiology have been studied, its impact on soil microbiota remains poorly understood despite its relevance to the agroecosystem. This two-year vineyard study assessed the impact of irrigation with ozonated water on soil bacterial and fungal microbiota using metataxonomic approaches. We hypothesized that ozone would negatively affect soil microbiota, also altering microbial groups of ecological interest.

The results showed that bacterial community composition underwent slight modifications following ozone application. However, neither bacterial and fungal community richness and diversity nor fungal community composition were significantly affected. Likewise, the relative abundance of beneficial groups such as plant growth-promoting bacteria and arbuscular mycorrhizal fungi, as well as potential pathogens associated with grapevine trunk diseases, did not exhibit significant variations. These limited effects may be related to the ozone concentration and exposure duration. Besides, soil is an active ozone consumer and its buffering capacity likely mitigates the oxidative impact of ozone, preventing significant alterations in microbial communities.

These findings suggest that ozone irrigation, a high-cost treatment, does not significantly impact soil microbiota, thereby questioning its potential as a field disinfectant. However, future studies should consider microbial viability, as well as annual, species-specific, niche-related variability and application form, to better understand its effects on the agroecosystem. © 2025 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.