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IVES 9 IVES Conference Series 9 First results obtained with a terrain model to characterize the viticultural «terroirs» in Anjou (France)

First results obtained with a terrain model to characterize the viticultural «terroirs» in Anjou (France)

Abstract

En Anjou, une méthode de caractérisation des terroirs viticoles a été développée. Elle utilise un modèle de terrain basé sur la profondeur de sol et son degré d’argilisation. Il génère trois types de milieu sol : roche, altération, altérite. Les hypothèses testées concernent l’effet des trois types de milieu sur l’àlimentation en eau, la précocité de cycle de la vigne, le potentiel de vigueur et de rendement ainsi que sur la composition des baies.
Pour cela, un réseau de parcelles expérimentales de Chenin et Cabernet franc, comportant 3 répétitions par unité de terroir, a été mis en place. Il permet d’étudier les deux principaux systèmes géologiques de l’Anjou (Briovérien et Ordovicien-Dévonien)
Les résultats de 2000 et 2001 (années pluvieuses) montrent pour le cépage Chenin que le débourrement est significativement plus précoce en milieu roche qu’en milieu altérite. Le milieu altération ne se différencie pas significativement des deux autres. En 2000, des différences significatives d’alimentation hydrique entre terroirs sont apparues à partir du mois de septembre pour le cépage Chenin, et à un degré moindre pour le Cabernet franc. Ainsi, le milieu roche entraîne un abaissement significatif du potentiel hydrique foliaire de base, malgré l’année pluvieuse. Le milieu altération ne se différencie pas du milieu roche. Sur spilite de l’Ordovicien-Dévonien, le milieu roche induit une contrainte hydrique plus forte que sur métagrauwacke du Briovérien. Les résultats d’analyses de δ13C des baies sont très significatifs et confrrment ceux du potentiel hydrique foliaire. Ces deux types de mesures montrent que la contrainte hydrique pour la vigne est significativement plus forte en milieu roche qu’en milieu altérite. Les baies du cépage Chenin, en milieux roche et altération, sont significativement plus riches en sucres qu’en milieu altérite. Les milieux roche sur schiste gréseux et métagrauwacke ont des teneurs inférieures à celles de la spilite. Avec le Cabernet franc, les baies semblent plus riches en sucres sur milieu roche que sur altérite. Le milieu roche induit des teneurs en anthocyanes et polyphénols significativement supérieures à celles de l’altérite; et cela aussi bien dans les baies que dans les vins. Ces premiers résultats, encore fragmentaires, semblent confirmer la plupart des hypothèses de travail avancées.

In Anjou vineyard, the viticultural “terroirs” are studied with a method based” on the concept of the “Basic Terroir Unit” (BTU). To identify and cartography the BTU, a terrain model based on the depth and the clay content of soil was elaborated. It generates three kinds of soil environments which are designated by the French terms of: “roche, alteration and altérite”. The hypothesis tested concern the effect of each type of environment on water supply regime, earliness and vigour of vine which are the main factors of the “terroir” effect, and also on berries composition.
A multisite network of 21 plots with Chenin and Cabernet franc varieties, was established in 2000. It samples the two main geologic systems of Anjou (Brioverian and Ordovician­ Devonian), with three replicates for each BTU.
The first results (2000 & 2001), show for the variety Chenin that bud break is earlier in the “roche” environment than in the “altérite” environment. The “alteration” is not different from were detected in September; for the Chenin variety and, at a less degree, for the Cabernet franc. So the “roche” environment involves a significant lowering of the predawn leaf water potential, despite a rainy season. There are no significant differences between the “alteration” and the “roche” environment. The “roche” environment on spilite from Ordovician-Devonian involves significantly more water constraint than on metagrauwacke from Brioverian. The results of δ13 C measurements in berries are highly significant and confirm the ones of the predawn leaf water potential. These two kinds of measures show that the water availability is greater in the “altérite” environment than in the “roche” environment. The must sugar content on “roche” and “alteration” environments was significantly higher than on “altérite”. The rock environment on sandstone schist and metagrauwacke have a lesser sugar content than on spilite. With the Cabernet franc variety, the “roche” environment involves significantly greater anthocyanins and polyphenolic amounts than the “altérite”; both in berries and in wines. These first results seem to confirm most of the hypotheses.

DOI:

Publication date: February 15, 2022

Issue: Terroir 2002

Type: Article

Authors

Fabrice BODIN and René MORLAT

Unité Vigne et Vin. Centre INRA d’Angers. 42 rue Georges Morel. BP57.
49071 Beaucpuzé Cedex. France

Contact the author

Keywords

modèle de terrain, précocité de cycle, alimentation hydrique, cépage, composition des baies
terrain model, precocity, water supply regime, grape variety, berry composition

Tags

IVES Conference Series | Terroir 2002

Citation

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