Permanent cover for soil and water conservation in mechanized vineyards: A study case in Piedmont, NW Italy

Vineyards' soils are especially threatened by the risk of soil compaction and soil erosion, with negative consequences for wine production and provisioning of ecosystem services. The adopted inter-rows soil management influences the response of vineyard to different types of rainfall events, in terms of runoff and soil erosion. Actually, the use of cover crops in vineyards is widely considered as an effective measure for conservation of water and soil. A 3-years study was carried out in Piedmont (NW Italy) to evaluate the effectiveness of grass cover as a soil water conservation measure, compared with tillage, and particularly the influence of different types of rainfall events and tractor traffic in determining hydrological and erosive response of the vineyard. During the investigation period (November 2016 - December 2019), climate variables, runoff, and soil losses were continuously monitored along with vineyard management operations. Very different yearly precipitation characterized the observed period, including the driest and wettest year in the last 20 years. Runoff and soil erosion caused by different types of rainfall events (long-lasting, intense and normal) in two vineyard's plots managed with permanent grass cover and tillage, respectively, have been compared. In addition, the influence of the number of tractor traffic was taken into account. Runoff volume was principally affected by soil management, while sediment yield was influenced by the type of event.