Land-use legacy shapes soil- and root-associated microbial communities, modifies nutrient cycling, and influences vine physiology

Soil microbial communities are central to ecosystem functioning, influencing organic matter decomposition, nutrient cycling, and plant nutrition. Plant microbiomes, including mycorrhizal symbioses, play a key role in plant nutrient uptake and are strongly influenced by soil management. Land-use change, agroforestry management, and landscape structure can strongly impact the composition of soil microbial communities and plant development. In France, the structure of wine-growing landscapes can be highly heterogeneous. However, the combined effects of agroforestry practices and landscape heterogeneity on soil microbial communities in viticultural systems remain poorly documented. To better understand these effects, we conducted a controlled experiment using soils collected from a vineyard and an adjacent forest within the same landscape. Specifically, we compared vineyard soil, forest soil and their mixture to assess how their associated microbiota influence vine growth, plant-driven microbiota recruitment, and microbial activities. Although physicochemical analyses showed that forest soil contained substantially higher levels of organic matter (283.7 vs 54.3 g·kg −1 dry soil) and nitrogen (13.3 vs 3.2 g·kg −1 ), the enzymatic activity patterns differed between soils, with vineyard and mixed soils exhibiting higher functional activity than forest soil. We found that vine growth and nitrogen status were significantly influenced by soil origin. Plants grown in mixed soil exhibited greater aboveground biomass and development (fresh weight ∼32 g·plant −1 ; length ∼57 cm) than those grown in vineyard soil (∼19 g·plant −1 ; ∼28 cm) or forest soil (25.60 g·plant −1 ; ∼32.16 cm). Moreover, fungal and bacterial diversity analyses revealed distinct microbial community compositions, with vineyard soils hosting taxa adapted to disturbed environments, whereas forest soils harbored greater microbial richness. Overall, these results indicate that differences in vine growth cannot be explained solely by soil organic matter content and may also reflect differences in soil microbial communities, especially in the mixed soil treatment.