Farmers face changing socio-economic and environmental conditions. This may lead them to modify their cropping systems, sometimes in a rapid way. For this, they need to anticipate the response of the biophysical system to the changes they introduce. Consequently, the transition from the current cropping system to the new one has to be well understood and managed (Pahl-Wostl, 2007). In the case of perennial crops as grapevines, modifications that can be brought to the cropping system are limited because of spatial and temporal constraints (e.g., crop rotations are impossible). In vineyards, the introduction of an intercrop is a developing practice in relation to the various benefits it can provide (mitigation of runoff and erosion, control of grapevine vigour...). Nevertheless, in Mediterranean regions, it remains poorly extended as farmers fear competition for water and mineral resources between the two crops. Indeed, this region experiences summer droughts with a high intraand inter-annual rainfall variability (from 300 to 1200 mm per year). Moreover, for perennial crops like grapevine, the performances of the current year depend on the climatic conditions that prevail during both the current year and the previous one (Boss et al., 2002). The mechanisms of adaptation to a new cropping system remain misunderstood. This work aimed at combining experiment and modelling to better understand and manage perennial cropping systems in changing conditions. We assumed that an adaptive management of the cropping system, i.e., more reactive to the climate variability, could be more sustainable. On one hand, an experiment was carried out to study the immediate and delayed consequences of the introduction or destruction of an intercrop on the growth and yield formation of grapevine. On another hand, a bio-decisional model was elaborated to simulate dynamic and adaptive management strategies for intercropped vineyards, and evaluate them according to agronomic and environmental pe