Soil and water conservation in terraced and non‐terraced cultivations: an extensive comparison of 50 vineyards

Abstract

AbstractUnderstanding the soil and water conservation (SWC) impact of steep‐slope agricultural practices (e.g. terraces) has arguably never been more relevant than today, in the face of widespread intensifying rainfall conditions. In Italy, a diverse mosaic of terraced and non‐terraced cultivation systems have historically developed from local traditions and more recently from the introduction of machinery. Previous studies suggested that each type of vineyard configuration is characterised by a specific set of soil degradation patterns. However, an extensive analysis of SWC impacts by different vineyard configurations is missing, while this is crucial for providing robust guidelines for future‐proof viticulture. Here, we provide a unique extensive comparison of SWC in 50 vineyards, consisting of 10 sites of 5 distinct practices: slope‐wise cultivation (SC), contour cultivation (CC), contour terracing (CT), broad‐base terracing (BT) and oblique terracing (OT). A big‐data analysis approach of physical erosion modelling based on high‐resolution LiDAR data is performed, while four predefined SWC indicators are systematically analysed and statistically quantified. Regular contour terracing (CT) ranked best across all indicators, reflecting a good combination of flow interception and homogeneous distribution of runoff and sediment under intense rainfall conditions. The least SWC‐effective practices (SC, CC, and OT) were related to vineyards optimised for trafficability by access roads or uninterrupted inter‐row paths, which created high upstream‐downstream connectivity and are thus prone to flow accumulation. The novel large‐scale approach of this study offers a robust comparison of SWC impacts under intense rainstorms, which is becoming increasingly relevant for the sustainable future management of such landscapes.