Characterizing a vine terroir by combining a pedological field model and a survey of the vine growers in the Anjou Region (France)

The aim of this research was to develop an operational method of characterization of «terroirs» in response to the request from wine professionals. A study based on both a survey of vine growers and a characterization of the natural factors of «terroir» (geological, pedological and mesoclimatic components) using the concept of Basic Terroir Unit (B.T.U) was made in 18 communes of the Anjou region. The natural factors of “terroir” were characterized by (1) a geological component (stage and nature of the parent rock) and (2) an agro-pedological component studied according to a field model allowing to distinguish three kinds of soil environments named : Rock, Alteration and Altérite. Each of them represent a functioning unit in wich an homogenous response in terms of vine behaviour can be expected. The approach based on the survey of vine growers was developed in order to replace the network of experimental plots of land formerly used to integrate the plant behaviour in its environment. These networks required considerable investment in time and money. Our study showed that vine growers perceived correctly the behaviour of the vine through different variables relative to the soil, the climate and the plant. They distinguished particularly well between two of the environments (Rock and Alterite) generated by the model. There was good agreement between the results obtained with the two approaches (survey and characterization of natural factors of «terroirs»).