Terroir is increasingly important today in wine markets. In a large wine production area such as the Loire Valley, the whole territories/terroirs can be distinguished according to different combinations of geological, soil, climatic and landscape features but are also characterized by their differences and likenesses in terms of combinations of terroir units and practices. The objective of the study is to obtain a systemic analysis of the typicality of wines conferred by the terroir in a large territory and identify which practices are associated with the production of typical wines in a given territory or a specific area of wine production. In a previous work, a method was designed to identify some viticultural and enological practices that allow distinguishing wines at the scale of a PDO (Protected Designation of Origin1), in a small territory. The new challenge is to extend the method to the different subbasins of the Loire Valley, and to check if the same results can be obtained for other types of wines. The extension of our method to study the practices of the winegrowers requires some adaptations before it may be applied on a larger scale as in a Vineyard Loire Valley Observatory. The choice of the strategy was to combine a small scale diagnosis with a participatory method with Research Development and Extension (RDE) officers to answer our questions and organize ViLVO. We were thus able (i) to solve some problems such as the working organization of ViLVO users and databases property, (ii) to combine RDE officers and searchers goals around the identification of significant practices associated with wine quality and fame and (iii) to focus on outstanding practices involved in terroir typicality of Loire Valley wines