Terroir 2010 banner
IVES 9 IVES Conference Series 9 Terroir characterization from cv. Merlot and Sauvignon plots follow-up within the scope of wine-production : “Vins de Pays Charentais” in the Cognac eaux-de-vie vineyard area

Terroir characterization from cv. Merlot and Sauvignon plots follow-up within the scope of wine-production : “Vins de Pays Charentais” in the Cognac eaux-de-vie vineyard area

Abstract

[English version below]

Dans les études des terroirs, il est souvent délicat d’établir des zonages et de mesurer les effets de l’environnement sur les vins. Avec plus d’un million d’hectares dans l’aire d’appellation délimitée, le terroir du célèbre vignoble de Cognac est bien connu pour ces eaux-de-vie et ainsi divisé en 6 crus.
Cette étude vise à décrire le terroir des Vins de Pays Charentais (VPC) produits dans le vignoble Cognaçais. Les principaux cépages spécifiquement destinés à la production de VPC (Merlot et Sauvignon blanc) ont été étudiés en collectant de nombreuses données sur 5 millésimes et 35 parcelles représentant la diversité agro-pédo-climatique de la région. Comme souvent dans les essais au champ les expérimentateurs ont été confrontés à de multiples facteurs croisés et de nombreux paramètres ont été suivis. A ce stade, peu de données climatiques ont été introduites et les données de dégustation n’ont pas été incluses.
Une expertise préliminaire a permis de sélectionner certaines variables, classées en 4 groupes distincts : données climatiques et pédologiques, matériel végétal, phénologie et vinification.
L’analyse statistique exploratoire a fait ressortir certaines variables influentes, par exemple l’ère géologique et le type de sol, qui distinguent des unités cohérentes d’un point de vue géographique notamment les îles de Ré et d’Oléron. Le comportement des vignes VPC est ensuite étudié sur chacune de ces unités afin de définir ces terroirs viticoles.
Les groupes de parcelles destinées à la production de vin semblent concorder pour une bonne part aux crus des eaux de vie de Cognac même si le cépage et le type de produit diffèrent. Ces résultats vont permettre de réfléchir sur différents moyens d’optimiser l’effet terroir par les pratiques des producteurs de VPC sur les différents terroirs.

Zoning and understanding the effects of the environment expressed in vine products has always been a difficult work to start off with terroir. Thus, with more than one million hectares in the delimited appellation area, the famous Cognac vineyard terroir is well-known for eaux-de-vie and divided in 6 vintages areas since the beginning of the 20th century.
This project aims at describing the terroir for wines named “Vins de Pays Charentais” (VPC) produced in the Cognac vineyard. Main cultivars specifically used to produce VPC (Merlot and Sauvignon Blanc) were studied by collecting a set of data, using 6 years and 35 plots to represent the diversity of environmental and cultural situations in the area. As often in field trials, experimenters were confronted with many crossed factors and numerous variables were measured. At this stage, only few climatic data is available. A preliminary expertise allowed to choose some of the variables sorted in 4 distinctive groups : soil and climate data, plant material, vine cycle and grapes and then wine-making process. Tasting data was not taken into account regarding as its robustness.
The statistical exploratory analysis brought out some influential variables, as for example geological era and soil type, that clearly segregate coherent geographic units, notably Ré and Oléron islands which are breaking away. From then on, to define various “wine-terroirs” these clusters should each correspond to consistent VPC grapevine behavior and wines.
Most climatic data still has to be crossed with the plots groups sorted, but the clusters of wine producing plots already appears to tally, at least partly, Cognac firewater vineyards classification even if cultivars and type of product differ. These results allow to consider various means to optimize terroir effect by VPC winegrowers’ practices on each plot, depending on its cluster.

DOI:

Publication date: December 3, 2021

Issue: Terroir 2010

Type: Article

Authors

BERNARD F.M. (1), PREYS S. (2), GIRARD M. (3) & MORNET L. (4)

(1) IFV, Institut Français de la Vigne et du vin, 15 Rue Pierre Viala, 16130, Segonzac, France
(2) Ondalys, 385 Avenue des Baronnes, 34730, Prades-Le-Lez, France
(3) Chambre d’Agriculture de Charente-Maritime, 3 Boulevard Vladimir, 17100, Saintes, France
(4) Chambre d’Agriculture de Charente, 25 Rue de Cagouillet, 16100, Cognac, France

Contact the author

Keywords

Vins de Pays Charentais, Merlot, Sauvignon, Terroir viticole, Sol, Millésime
Vins de Pays Charentais, Merlot, Sauvignon, Wine-terroir, Soil, Vintage

Tags

IVES Conference Series | Terroir 2010

Citation

Related articles…

How can historical cultivars mitigate the effects of climate change?

IFV, INRAe and the national network “Partenaires de la Sélection Vigne” representing 37 organizations from the different wine regions, have been working increasingly closely over the last 2 decades towards the preservation of the French varietal patrimony. There are approximately 600 patrimonial varieties according to INRAe and SupAgro Montpellier experts, including ancient cultivars (400) and intravarietal crossbreeds obtained since the 19th century. In the context of a drastic reduction in such varieties from the mid 1980’s in favor of mainstream varieties, it was essential to carry out an inventory of old vines and vineyards. INRAe Vassal collection plays a key role here as it holds the largest diversity available, along with a rich bibliography and herbariums, offering us the opportunity to document and double check the identity of a cultivar, consolidating the expertise of ampelographers. The work is carried out in several stages, from verifying the existence of a variety in a small region, through to rehabilitation. During this session, the authors present the process that leads to the official registration of a variety. After this, IFV selection center takes over to initiate the process of selection and propagation. A specific focus within regions such as the Alps, Champagne and the South-West will provide details of the full procedure. Bia, Bouysselet, Chardonnay rose, Mecle and the aptly named Tardif, are some of the cultivars that have followed this procedure. Furthermore, a recent regulation established by INAO on “varieties of interest for adaptation purposes” might boost uptake by growers. Since 2006, 36 historical cultivars have been registered. Most of these have been neglected in the past due to late maturity, lack of sugar and high titratable acidity at harvest time. Such characteristics are today considered as positive qualities, not only in mitigation of the effects of climate change, but also as an opportunity for restoring diversity…

Copper contamination in vineyard soils of Bordeaux: spatial risk assessment for the replanting of vines and crops

Copper (Cu) is widely and historically used in viticulture as a fungicide against mildew. Cu has a strong affinity for soil organic matter and accumulates in topsoil horizons. Thus, Cu may negatively affect soil organisms and plants, consequently reducing soil fertility and productivity. The Bordeaux vineyards have the largest vineyard surfaces (26%) within French controlled appellation and a great proportion of French wine production (around 5 million hl per year). Considering the local context of vineyard surfaces decreasing (vine uprooting) and possible new crop plantation, the issue of Cu potential toxicity rises. Therefore, the aims of this work are firstly to evaluate the Cu contamination in vineyard soils of Bordeaux, secondly to produce a risk assessment map for new vine or crop plantation. We used soil analyses from several local studies to build a database with 4496 soil horizon samples. The database was enhanced by means of pedotransfer functions in order to estimate the bioaccessible (EDTA-extractable) Cu in soils of samples without measurements. From this database, 1797 georeferenced samples with CuEDTA concentrations in the topsoil (0-50 cm depth) were used for kriging interpolation in order to produce the spatial distribution map of CuEDTA in vineyard soils. Then, the spatial distribution of Cu was crossed with vine uprooting surfaces and municipality boundaries. CuEDTAconcentrations ranged from 0.52 to 459 mg/kg and showed clear anomalies. Our results from spatial analysis showed that almost 50% of vineyard soil surfaces have CuEDTA concentrations higher than 30 mg/kg (moderate risk for new plantation) and 20% with concentrations higher than 50 mg/kg (high risk for new plantation). A decision-support map based on municipalities was realised to provide a simple tool to stakeholders concerned by land use management.

Better understand the soil wet bulb formation with subsurface or aerial drip irrigation in viticulture

The gradual change in rainfall patterns experienced in the south of France vineyards, especially around the Mediterranean sea, means that the vines are increasingly subject to summer drought. The winegrowers developped the use of irrigation techniques to ensure the maintenance of competitive yields in the production of wines under Protected Geographical Indication label. In practice, drip irrigation pipes can be installed above the ground or buried into the soil as well as at different distances from the vine row. The objective of this study was to examine the profiles of the wet bulbs of the soil obtained from two drip irrigation systems : aerial drip located under the vine row and subsurface drip placed in the middle of the inter-row. This experiment took place over two consecutive seasons (2020-2021) on a 3.4 ha Viognier plot in the Mediterranean region (PGI Oc, France) on sandy clay soil. The annual rainfalls were less than 400 mm. Soil water content probes were installed at different depths (20 – 40 – 60 – 80 cm) and at different lateralities from the vine row (30 – 60 – 90 – 120 cm) to control the formation of the soil wet bulb during irrigation. The mapping and the analysis of the data allowed a better understanding and differentiation of the water percolation when irrigating with subsurface or aerial drip. For the same amount of water and without differences of vine water status, it is shown that in a subsurface drip irrigation situation, the size of the wet bulb formed is larger than in aerial drip irrigation system.

austrianvineyards.com: online viewer of all designations of Austrian wine

To digitally record and present all the origins of Austrian wines in the same perfect and clear way was the motivation for the Austrian Wine Marketing Board (Austrian Wine) to start with the project in 2018. In June 2021 the results were presented to the public in an online viewer showing all the designations of Austrian wine, available at https://austrianvineyards.com in a largely barrier-free manner. The online viewer provides tailored individual maps fitted to the respective zoom level. The smallest unit of wine-origins in Austria is called Ried and is displayed in a plot-specific manner highlighting areas under vine. Information on the Ried include administrative district, winegrowing municipality, cadastral municipality, large collective vineyard site, specific winegrowing region, generic winegrowing region, winegrowing area and, in many cases, an illustrative picture. Complementary data on the size, elevation (minimum-maximum), orientation (in 8 sectors plus flat) and gradient (minimum, maximum, average) are based on the area under vine according to the EU’s Integrated Administration and Control System. Additional information covers climate data. The diagrams are taken from the monthly breakdown of data in the annals of the Central Institute for Meteorology and Geodynamics, Austria provide a display of values for air temperature, precipitation, and sunshine hours for the reference year and the long-term average. Seasonal aggregated data on temperature, precipitation, and sunshine hours complete the display. Short descriptions with emphasis on geology and soil, field name in historical maps, etymology of the denomination, and main planted variety complements the available information for the main designations in the online viewer. These descriptions are compiled by winegrowers, geologists, historians, and journalists. All the information and data can be extracted to a pdf-file. Printed vineyard maps are also available. Missing content regarding wine origins in Styria will be completed in winter 2021/22.

Impact of climate variability and change on grape yield in Italy

Viticulture is entangled with weather and climate. Therefore, areas currently suitable for grape production can be challenged by climate change. Winegrowers in Italy already experiences the effect of climate change, especially in the form of warmer growing season, more frequent drought periods, and increased frequency of weather extremes.
The aim of this study is to investigate the impact of climate variability and change on grape yield in Italy to provide winegrowers the information needed to make their business more sustainable and resilient to climate change. We computed a specific range of bioclimatic indices, selected by the International Organisation of Vine and Wine (OIV), and correlated them to grape yield data. We have worked in collaboration with some wine consortiums in northern and central Italy, which provided grape yield data for our analysis.
Using climate variables from the E-OBS dataset we investigate how the bioclimatic indices changed in the past, and the impact of this change on grape productivity in the study areas. The climate impact on productivity is also investigated by using high-resolution convection-permitting models (CPMs – 2.2 horizontal resolution), with the purpose of estimating productivity in future emission scenarios. The CPMs are likely the best available option for this kind of impact studies since they allow a better representation of small-scale processes and features, explicitly resolve deep convection, and show an improved representation of extremes. In our study, we also compare CPMs with regional climate models (RCMs – 12 km horizontal resolution) to assess the added value of high-resolution models for impact studies. Further development of our study will lead to assessing the future suitability for vine cultivation and could lead to the construction of a statistical model for future projection of grape yield.