Cover crop management influences soil properties and grapevine performance across three growing seasons in a subtropical vineyard

Cover crop management can modify soil conditions and grapevine performance, but these responses may depend on the vegetation-management strategy and growing season. This study evaluated the effects of different cover crop management systems on soil, physiological, yield, and fruit technological variables of Vitis vinifera L. cv. Viognier cultivated in Campo Largo, Paraná, Brazil, for three growing seasons (2023–2026; 2023/24, 2024/25, and 2025/26). The treatments were: T1, spontaneous vegetation (white clover in winter and Cynodon spp in summer) with herbicide application in the vine row; T2, spontaneous vegetation without herbicide; T3, black oat in winter and predominantly white clover + angola grass in summer; T4, common vetch in winter and mombaça grass in summer; and T5, multispecies cover crop mixtures in winter (black oat + rye + vetch + forage radish) and summer ( Cynodon ssp + buckwheat + mombaça grass). Cover crop biomass and macronutrient accumulation, soil chemical and physical properties, soil water content, and grapevine nutritional, physiological, vegetative, yield, and technological variables were evaluated. Data were analyzed using linear mixed-effects models accounting for repeated measurements across growing seasons, complemented by multivariate analyses. T4 (vetch and mombaça) and T5 (oats + rye + vetch + forage radish; and Cynodon ssp + buckwheat + mombaça) generally showed greater biomass production and accumulation of N, P, K, Ca, and Mg than systems based on spontaneous vegetation. Vegetation management also affected selected surface-soil properties, particularly available P, total organic carbon, total N, cation exchange capacity, bulk density, and soil water content, although responses varied among growing seasons. Grapevine leaf area (LA) and the Yield/LA ratio did not differ among treatments, whereas physiological responses were treatment- and season-dependent. The clearest yield response occurred in 2025/26, when T2 and T4 reached 11.06 and 11.12 Mg ha −1 , respectively, approximately 20% greater than T1 (9.21 Mg ha −1 ). Soluble solids and pH were unaffected by vegetation management, and differences in titratable acidity occurred only in 2023/24. Global multivariate profiles differed among treatments but were strongly season-dependent. Overall, sown cover crops increased biomass production, nutrient accumulation, and selected surface-soil attributes, but these responses did not consistently translate into greater grapevine yield or fruit technological maturity within the 3-year experimental period.