Effects of common inter-row management practices on vineyard soils in four European vineyard regions

Vineyards are often located in areas with poor soil quality and hilly terrain. Conservation agricultural management with the inclusion of cover crops helps to maintain or increase the existing soil fertility in these areas that are difficult to cultivate. However, there are also several reasons in favour of keeping vineyard inter-rows bare, including competition for water and nutrients, restrictions in pest control, and additional costs. As a result, a variety of site-adapted inter-row management systems have been developed in the different wine-growing regions. We investigated the effects of common management practices on soil organic carbon and soil physical parameters in topsoils of Austrian, French, Romanian, and Spanish wine-growing regions. In each region, we analysed management systems with and without cover crops. The comparison between the vineyard regions shows the variety of management intensities across the vineyard regions and their effects on soil quality parameters. Due to the differences in climate, soil, and management systems and, in particular, the mechanical soil disturbance intensity, bare soil, and cover crop management led to a broad range of soil organic carbon stocks, soil structure parameters, and soil hydraulic properties. While cover crop management caused an increase in carbon stocks in most vineyards compared to bare soil management, cover crop management in Spain was not effective in increasing soil organic carbon accumulation. In line with the increase in organic carbon also the measured soil structure parameters improved, yet the extent depended on the type and intensity of soil disturbance. The least clear effects of inter-row management systems were found for soil hydraulic parameters. As the local management strategies are a combination of adaptations to local conditions, farmers' experiences, and historical developments, the findings from the comparison of the systems can be used to rethink local strategies and improve the individual systems. This primarily concerns the type and intensity of cover crop management.