Integrated grass-livestock-viticulture system triggers soil microbiome, grape growth, and grape disease suppression cascades

Soil microbiomes play a vital role in agricultural ecosystems. Cover crops are a key vineyard management strategy, that improves soil health, suppresses weeds, and promotes nutrient cycling. The grass-livestock-viticulture system further enhances sustainability by optimizing resource use, increasing productivity, and reducing inputs. However, the underlying ecological mechanisms are not well understood. This study investigates these mechanisms from a microbiological perspective. Field investigations showed that both grass planting and sheep grazing significantly enhanced leaf growth, with grazing further promoting new shoot development. Both treatments also reduced grape disease incidence compared to clean tillage. Microbial analysis revealed that enhanced grape growth and disease suppression were closely associated with shifts in the microbial community. Grazing significantly increased bacterial diversity in the inter-row soil but decreased fungal diversity in the grapevine root zone. Both grass planting and grazing increased fungal diversity in the inter-row. Grapevines in these treatments recruited beneficial microbes that supported nutrient cycling and pathogen suppression, including bacteria (e.g., Aggregatilinea , Niallia , Nocardioides ) and fungi (e.g., Petriella , Cheilymenia , Pseudaleuria ), while suppressing pathogenic fungi (e.g., Fusarium , Aspergillus , Gibberella ), especially under grazing. Microbial functional genes involved in nitrogen, phosphorus, and carbon cycling were significantly enriched, especially under grazing. Both treatments also increased bacterial network complexity and positive interactions, while grazing simplifying but strengthening fungal connectivity in the root zones. Our study provides valuable insights into microbiome-mediated ecological effects in integrated agroforestry systems, guiding the optimization of soil microbiomes to promote sustainable vineyard production. • Grass-sheep-grape system improves grape growth and health relate to microbiome. • Integrated system enriches beneficial bacteria and suppresses pathogens. • Bacterial networks expand; fungal networks simplify but connect better. • Microbial genes for C, N, and P cycling are upregulated, especially with grazing. • Microbial shifts closely correlate with soil properties.