Influence of under-vine soil management on bulk soil microbiota and properties in three Tannat vineyards in Uruguay

The vineyard soil microbiome plays a pivotal role in agroecosystem health and productivity, influenced by agricultural management and environmental factors. This study examined the composition of prokaryotic and fungal communities across three Tannat vineyards in Uruguay with the same conventional under-vine soil management (bare soil maintained with herbicides [BS]). Additionally, within each vineyard, a permanent living mulch (PLM) was established to explore the effects of this under-vine management on soil microbiota. The long-term cultivation of Tannat grapevines combined with consistent under-vine herbicide use may have contributed to a homogenization of soil microbial community composition across vineyards, despite differences in soil type, altitude, and management histories. A few differentially abundant taxa were detected: in Vineyard 3 Rubrobacter was less abundant compared to the other vineyards, while in Vineyard 1 the class Sordariomycetes and the genus Metarhizium were more abundant, and the genus Boeremia was less. Prokaryotic and fungal communities' composition analyses within vineyards revealed a significant impact of under-vine management solely in Vineyard 2, the one with a 10-year implementation of PLM. PLM improved soil properties such as basal respiration, soil protein, potentially oxidizable carbon and bulk density. Also, the family Latescibacteraceae, and the genera Cladophialophora, Nigrospora, and Pseudopithomyces were more abundant in PLM. Our findings emphasize the need for long-term studies to capture microbial responses to soil management. Future studies involving more sites and managements could identify deeper differences, aiding in the identification of viticultural zones based on microbial patterns.