Soil management modulates vineyard airborne fungal communities and impacts fungal disease pressure

Viticulture increasingly faces challenges posed by global warming and its effects on yield and berry composition, highlighting the need for sustainable yet effective management strategies. In a two-year field trial conducted in one vineyard, we compared conventional tillage (T) and no-till (NT) regimes with three inter-row treatments: compost mulch (C), pruning-wood mulch (PW), and living cover crops (CC), while using a high-efficiency captaspore vacuum sampler to track shifts in the airborne fungal diversity followed by visual assessment of fungal disease symptoms during each growing season. Under relatively dry seasonal conditions, compost mulching was associated with lower downy and powdery mildew pressure, whereas these differences were not detectable under wetter conditions. The use of cover crops appeared to modulate grape sugar content, resulting in lower bunch weight and higher degrees Brix. Tillage regime was associated with shifts in airborne fungal richness and composition, including changes in the relative abundance of taxa related to Erysiphe necator. However, seasonal climatic conditions explained a substantial proportion of the observed variability. Overall, soil tillage emerged as the dominant driver shaping the airborne fungal community composition, while compost mulching exerted disease-suppressive effects only under moderate climatic pressure. These findings suggest that soil management may modulate the soil-air microbial interface and disease pressure in a climate-dependent manner, rather than acting as a dominant standalone driver.