A high-resolution physical modelling approach to assess runoff and soil erosion in vineyards under different soil managements

Steep-slope viticulture is a common practice in the Mediterranean basin, and provides landscapes of considerable socio-economic value. However, these complex agricultural systems are intrinsically fragile. One of the main problems is soil erosion due to extreme rainfall events. This may cause a progressive reduction in soil fertility and the occurrence of instabilities and land degradation phenomena. To worsen this condition there is the increasing mechanisation of agricultural management causing soil compaction, and the pressure of climate change, with an intensification of extreme weather events. In this context, vineyard soil management plays a key role, as it can accelerate or mitigate overland flow and soil erosion phenomena. There are various techniques for quantifying these processes, often based on field measurements through prolonged data collection using experimental plots. However, the advent of new technologies in remote sensing opens new frontiers in the acquisition of high-resolution spatial data. Indeed, they could be used in runoff/erosion simulation models and integrated with site-specific data. The aim of this paper is to assess runoff and soil erosion processes in vineyard under four different soil managements. Specifically, four practices were tested: (1) Reference (inter-row managed with standard farm grass cover; RF); (2) Continuous Tillage (bare soil obtained by continuous mechanical weeding using roto-tiller; CT); Nectariferous (a mix of herbaceous species capable of attracting insects favouring inter-row biodiversity; NF); (4) Single Tillage (inter-row weeding once a year using roto-tiller; ST). The research proposes a modelling approach using a physically-based model (SIMWE) using samples of runoff and sediment as an assessment, collected with a low-cost methodology. In particular, a cost-effective approach easily replicable in different contexts (such as developing countries) is sought. In addition to cultivation specifics, areas of soil compacted by the passage of agricultural vehicles were also analysed using the connectivity index. In general, results show an interesting capacity of ST in mitigating soil erosion, as well as for NF. Furthermore, the negative role of wheel tracks as preferential pathways for surface runoff and sediment is highlighted. Finally, the work shows that CT aggravated soil erosion as compared to RF.