Effect of soil management and tractor traffic on the long-term assessment of sloping vineyard soil compaction

In sloping vineyard soil is subjected to a series of degradation processes, among which compaction caused by tillage operation and vehicular traffic, that can influence soil physical and hydrological properties with effects on crop production and quality of environment (Lagacherie et al., 2006). Considering the significance of these impacts, soil compaction has been recognized as one of the threats related to land degradation identified by the European Soil Framework Directive (2006). The aim of the study was to assess the influence of soil management on compaction in hillside vineyard surface, in a long period of monitoring. The experimental trial has been conducted since 2004 and data of penetration resistance (PR) and bulk density (DB) have been collected from three plots of a Barbera vines with rows along the slope. Soil PR was measured by means of a recording penetrometer (Walczak et al., 1973) and BD by core method (Blake and Hartge, 1986). Changes in soil structure due to compaction by tractor traffic and different inter-row tillage (conventional tillage vs. reduced tillage vs. grass cover), analyzing spring and autumn sampling, are reflected in cone index (CI) of penetrometer and BD trend. Cone index was significantly higher with grass cover and reduced tillage than conventional tillage, with the opposite trend for BD where the grass cover appeared to have suffered to a lesser extent the effects of compaction due to vehicle traffic. In general Cl was higher in the tractor tracks than in the middle, and showed lower values during the spring following the recovery of soil compaction occurred after winter precipitation.