The "Terroirs d'Anjou" project led by the Agronomy sector of the Vine and Wine Research Unit of the INRA center in Angers aims to characterize the viticultural terroirs in a study area which includes 29 municipalities in the Maine et Loire and cuts across the Anjou, Coteaux du layon and Coteaux de l'Aubance appellation areas.
Different terroirs have been identified in Bolgheri area (a viticultural appellation in the Tirrenian coast of Tuscany) by the aid of pedological, landscape and agronomic observations in 1993. Numerous preliminary observations suggested that wines obtained from these different terroirs were unique.
Temperature has a decisive influence on the growth and development of plants (Carbonneau et al., 1992). In particular, in the case of the vine, the temperature is an omnipresent variable in the climatic indices (Huglin, 1986). For reasons of convenience, these indices use the temperature of the air measured under shelter in a meteorological station, making the implicit hypothesis of a concordance between this temperature and that of the sites of perception of the thermal stimulus by the plant. However, development may be more dependent on soil temperature than air temperature (Kliewer, 1975). Morlat (1989) thus verified that the variability in the precocity of the vine, positively correlated with the quality of the harvest and of the wine in the Loire Valley, was mainly explained by differences in temperature of the root zones.
The analysis of the distribution of natural plant populations allows an ecological characterization of cultivated environments in thermal, water and trophic terms; it guides the choice or selection of plants (or grape varieties) to cultivate (Astruc et al ., 1984, 1987; Delpoux, 1971; Jacquinet and Astruc, 1979). This approach has given good results in areas where the topography is the determining factor in the ecological differentiation of the terroirs.
Franciacorta is a viticultural area which extends in the hills to the South of Iseo lake in Lombardy. It is particularly famous for the production of sparkling wines obtained mostly from Chardonnay and Pinot blanc and noir grapes. The name of this territory is of medieval origin and appeared for the first time in 1277 as “Franzacurta”, from the Latin “franchae curtes”, i.e. “tax-free” monasteries. It was geographically delimited in 1429, when it was a territory of the Republic of Venezia.
Les fromages d’Appellation d’Origine Contrôlée (AOC) représentent un enjeu économique important pour la filière laitière (11 % des fromages produits en France sont des fromages d’AOC, et dans certaines régions de montagne, cette proportion dépasse 50 %). Les spécificités de ces fromages et leurs liaisons avec les caractéristiques du terroir constituent un système complexe où interagissent en particulier la technologie fromagère et les caractéristiques des laits (composition chimique en particulier). Ces dernières dépendent elles-mêmes des caractéristiques des animaux (origine génétique, facteurs physiologiques, état sanitaire) et de leur mode de conduite (alimentation, hygiène, traite…) (fig. 1). L’influence de ces facteurs de production (alimentation et type d’animal en particulier) sur les caractéristiques des fromages est fréquemment mise en avant par les fromagers, sur la base d’observations empiriques. Il existe cependant très peu de travaux expérimentaux sur le sujet, en raison, entre autres, de la difficulté de séparer correctement les effets propres de ces facteurs d’amont de ceux liés à la technologie fromagère.
“The vine and the wine are great mysteries. Only the vine makes us intelligible what is the true flavor of the earth”. Colette. The notion of terroir has always been the basis of the notion of AOC from which it is inseparable. It is moreover the definition of the production zone which was at the start of the attempts to set up the designation of origin, at the beginning of the century, after the phylloxera crisis.
In recent years, there has been a growing interest in characterizing the ecological environment of vineyard production, and the growing need to delimit and characterize with precision the different homogeneous viticultural units. This has allowed the development of new studies which have as their objective the Vineyard Zoning. The delimitation and characterization of wine-growing areas poses specific problems in Spain, not only linked to the specific characteristics of the territory, but also to the size, distribution and index of viticultural occupation in the designations of origin.
The winegrowers of the intercommunal cooperative cellar of Saint Hilaire d'Ozilhan have been practicing terroir selection for ten years. Five years ago, after having equipped themselves with an efficient commercial structure, and anxious to improve knowledge of their terroirs and to better control quantitatively and qualitatively the range of typicality that they can develop, they asked the Syndicate Général des Vignerons Réunis des Côtes du Rhône and the Institut Coopératif du Vin to help them set up an approach to better judge the behavior of the Grenache and Syrah grape varieties in the different terroirs, then to enhance this work through the improving product quality.
The reflections presented here are a synthesis of a set of research on the construction of a scientific logic concerning the relations between the terroir, the vine, the wine, and on the study of a product, the wine, considered as the resulting from many interactions between factors of various orders. This work has benefited greatly from discussions of an epistemological as well as a technical nature with all the researchers at URVV (Angers) and with our colleagues at the Institut National des Appellations d'Origine, over several years.
In this last ten years period, there has been many integrated and interdisciplinary studies to determine the aptitude of different zones to viticulture (Lulli et al., 1989 ; Costantini, 1992 ; Fregoni et al., 1992). The researches needed some différent knowledges about environment characteristics (soil, climate), ecology, vineyard management, vine genetic, winemaking and sensory analysis. The interaction of all these knowledge produced the assessment about the environmental vocation (Scienza et al., 1992). By means of this metodology, the “viticultural vocation” joined the word “zoning”, that is the territory parting for its ecopedological and geographical characteristics in relation to adaptative answer of winegrape (Morlat, 1989).
The studies developed by INRA and UV, in Angers, concern wine-growing areas and their optimized management, both from an agro-viticultural and oenological point of view. Previous work (Morlat, 1989) made it possible to give a scientific dimension to the concept of viticultural terroir and demonstrated the considerable influence of this production factor on the quality and typicity of wines (Asselin et al, 1992 ) . A methodology for the integrated characterization of terroirs, based on the "Basic Terroir Natural Unit" (considered as the smallest spatial unit of territory usable in practice, and in which the response of the vine is homogeneous), has been development (Riou et al , 1995).
The climatic component is one of the elements of the zoning of viticultural potential, alongside the geological and pedological components (Morlat, 1989; Lebon et al , 1993). Many climatic indices have thus been defined to estimate the potential for wine production at the scale of a region or a country (Carbonneau et al ., 1992). The main climatic variables used are temperature and radiation. We note in particular the indices of Branas, Huglin and Ribereau-Gayon (Huglin, 1986). However, few studies have been undertaken on the spatial variability of microclimatic conditions at the scale of a vineyard, a valley, or even a municipality.
In addition to studies on the edaphic and landscape characteristics of the environment (Dolédec, 1995), the characterization of the physiology of the vine and of parasitism during its vegetative cycle represents an essential component of knowledge and management of the terroirs.
The notion of terroir covers multiple components, from geology, pedology, geomorphology and climatology (Doledec, 1995), to aspects that are less well identified but which also intervene in the “typicality” of wines. This justifies the “zoning” approach (Moncomble and Panigaï, 1990) to define homogeneous areas, under the same agro-viticultural management and also identified at the product level (Morlat and Asselin, 1992).