Age-Associated Vineyard Soil Compaction Under Contrasting Decompaction Management in Northeastern Italy

Repeated machinery traffic can compromise vineyard soil physical quality, and older vineyards are characterised by longer-time machinery traffic. However, the relationship between vineyard age and soil compaction depends on management and local soil conditions. This study investigated age-associated compaction patterns under contrasting soil management. Moreover, we assessed whether traffic-induced topsoil compaction persisted across textures. Penetration resistance, volumetric water content (VWC), bulk density (ρb), soil organic matter (SOM), and plateau slope of the penetration profile were measured in four farms. First, three coeval vineyard blocks were analysed to quantify within-farm variability. Second, vineyards of different ages under different soil management were compared to assess age-associated patterns. Finally, a complementary experiment examined texture-related persistence of compaction using matched wheel-track and inter-row-centre observations. The coeval blocks differed in penetration-profile characteristics but VWC, ρb, SOM, and plateau slope were comparable. Under regular decompaction, the oldest vineyard had higher VWC and SOM and lower ρb. No consistent age-associated gradient was observed without decompaction. In the wheel track, mean cone index (CI) over the 0–45 cm layer was lower in the farm that regularly applied decompaction than in the one that did not. In clay soil, mean CI over 10 ± 2.5 cm was 80.5% higher in wheel tracks than at inter-row centres. The paired, block-aware texture analysis did not confirm a difference in the traffic effect between clay and clay-loam soils, while the clay traffic contrast remained significant after accounting for paired changes in VWC and ρb. These findings provide an initial indication that age-associated soil physical patterns may differ under contrasting decompaction management, although traffic imprints persisted in wheel tracks.