Terroir 1996 banner
IVES 9 IVES Conference Series 9 Methodology and zoning of A.O.C. natural soils. Example of “Pic Saint-Loup”

Methodology and zoning of A.O.C. natural soils. Example of “Pic Saint-Loup”

Abstract

[English version below]

Les travaux menés, dans le cadre du programme départemental pour la connaissance et la valorisation des terroirs viticoles, sur l’aire A.O.C. Coteaux du Languedoc / Pic Saint-Loup ont permis d’appliquer à l’échelle d’une Appellation d’Origine Contrôlée (13 communes), une méthodologie d’étude axée sur les aspects sol/climat/topographie qui concourent à l’identification des terroirs naturels, facteurs de typicité des vins. Dans un premier temps, un «diagnostic» de l’ensemble des critères du milieu naturel a été réalisé. Après avoir défini le cadre géologique, une prospection agro-pédologique au 1/10.000ème a permis de cartographier les différentes unités de sol ainsi que leurs positions topographiques. Les conditions climatiques sont également précisées d’un point de vue statistique (stations météo au sein de l’aire et stations limitrophes).

Dans un second temps, il était intéressant d’associer plus étroitement ces caractéristiques agro­environnementales à la culture de la vigne et à l’élaboration d’un vin typique. On approche ainsi au plus près de la notion de «terroir». Dans ce cadre, une singularité bioclimatique du Pic Saint-Loup a été identifiée sur la base de 3 indices viticoles corrélés à des caractéristiques intrinsèques et spécifiques des vins du Pic Saint-Loup. Les différentes unités de terroir naturel ont été cartographiées (typologie du sol, avec une estimation de la disponibilité en eau, associée au bilan radiatif) et décrites sous les différents aspects qui font leurs identités.

The works led, within the local program for the knowledge and the valorization of the wine soils, on the area A.O.C. Coteaux du Languedoc / Pic Saint-Loup allowed to apply on the scale of a registrated appellation origin (13 municipalities), a methodology of study centered on aspects ground/climate/topography which contribute to the identification of natural soils, factors of typical wines. At first, a «diagnosis » of ail the criteria of the natural environment was realized. Having definite the geologic frame, an agro-pedological prospecting to the 1/10.000th allowed mapping the various unities of ground as well as their topographic positions. The climatic conditions are also clarified by a statistical point of view (meteorological stations within the area and bordering stations).

In a second time, it was interesting to associate more strictly these agro-environmental characteristics to the culture of the vineyard and to the elaboration of a typical wine. One approaches so in closer the notion of “soil”. In this frame, a bioclimatic peculiarity of the Pic Saint Loup was identified on the basis of 3 wine indicators correlated in intrinsic and specific characteristics of wines of Pic Saint Loup. The various units of natural soil were mapped (typology of ground, with an estimation of the availability in water, associated to the radiative assessment) and described under the various aspects which make their identities.

DOI:

Publication date: February 15, 2022

Issue: Terroir 2002

Type: Article

Authors

Jean-Paul STORAÏ (1), Jean-Luc TONDUT (2)

(1) Conseil général de l’Hérault – 1000 rue d’Alco – F. 34087 Montpellier cedex 4
(2) Association Climatologique de l’Hérault – 85 avenue d’Assas – F 34000 Montpellier

Keywords

méthodologie, terroir naturel, sol, climat, viticulture
methodology, natural soil, ground, climate, vine growing(2) Association Climatologique de l’Hérault – 85 avenue d’Assas – F 34000 Montpellier

Tags

IVES Conference Series | Terroir 2002

Citation

Related articles…

Long-term drought resilience of traditional red grapevine varieties from a semi-arid region

In recent decades, the scarcity of water resources in agriculture in certain areas has been aggravated by climate change, which has caused an increase in temperatures, changes in rainfall patterns, as well as an increase in the frequency of extreme phenomena such as droughts and heat waves. Although the vine is considered a drought-tolerant specie, it has to satisfy important water requirements to complete its cycle, which coincides with the hottest and driest months. Achieving sustainable viticulture in this scenario requires high levels of efficiency in the use of water, a scarce resource whose use is expected to be severely restricted in the near future. In this regard, the use of drought-tolerant varieties that are able to maintain grape yield and quality could be an effective strategy to face this change. During three consecutive seasons (2018-2020) the behavior in rainfed regime of 13 traditional red grapevine varieties of the Spain central region was studied. These varieties were cultivated in a collection at Centro de Investigación de la Vid y el Vino de Castilla-La Mancha (IVICAM-IRIAF) located in Tomelloso (Castilla-La Mancha, Spain). Yield components (yield, mean bunch and berry weight, pruning weight), physicochemical parameters of the musts (brix degree, total acidity, pH) and some physiological parameters related with water stress during ripening period (δ13C, δ18O) were analysed. The application of different statistical techniques to the results showed the existence of significant differences between varieties in their response to stressful conditions. A few varieties highlighted for their high ability to adapt to drought, being able to maintain high yields due to their efficiency in the use of water. In addition, it was possible quantify to what extent climate can be a determinant in the δ18O of musts under severe water stress conditions.

Mesoclimate impact on Tannat in the Atlantic terroir of Uruguay

The study of climate is relevant as an element conditioning the typicity of a product, its quality and sustainability over the years. The grapevine development and growth and the final grape and wine composition are closely related to temperature, while climate components vary at mesoscale according to topography and/or proximity to large bodies of water. The objective of this work is to assess the mesoclimate of the Atlantic region of Uruguay and to determine the effect of topography and the ocean on temperature and consequently on Tannat grapevine behavior.

Diagnosis of soil quality and evaluation of the impact of viticultural practices on soil biodiversity in a vineyard in southwestern France

Viticulture is facing two major changes – climate change and agroecological transition. In both cases, soil quality is seen as a lever to move towards a more sustainable viticulture. However, soil biological quality is little considered in the implementation of viticultural practices. Gascogn’Innov (2017-2022) is an Operational Group funded by the European Innovation Partnership for Agriculture. As such, it brings together winegrowers from the south-west of France, scientists, advisors and technicians, around a project focused on viticultural soil biological functioning and the design of technical routes more respectful toward soil heritage. To achieve this, the project aims to acquire references on the impact of viticultural practices on soil biology from a dynamic way, and to test a methodology to integrate information provided by the soil bioindicators to manage farming systems. A set of indicators of soil biological quality are evaluated in the project: microorganisms (bacteria and fungi abundance and diversity), fauna (abundance and diversity of nematodes and earthworms), physico-chemical characteristics, soil structure assessment and degradation rate of organic matter. Based on a network of 13 plots that have been subject to an initial diagnosis in 2017, several agronomical practices to restore soil fertility are experimented to redesign the cropping system (for instance plant cover, organic matter inputs, reduction of herbicides, mineral fertilizers). System redesign was made in collaboration by winegrowers and an interdisciplinary group of experts (agronomists, biologists). Several indicators are measured on vine and soil at each vintage to assess vine health and productivity. At the end of the project (2021), a final diagnosis was carried out. Gascogn’Innov allowed to create a regional database on the quality of wine-growing soils, which permitted to evaluate the effect of practices according to soil types. Especially, decreasing the intensity of tillage and increasing the duration and diversity of grass coverage tends to increase the abundance of all the organisms studied. This project confirmed the value of soil biological quality indicators to drive the sustainability of practices, but also highlighted the key-role of expertise, in both agronomy and soil biology, to help winegrowers understand and appropriate their soil quality diagnoses.

VINIoT: Precision viticulture service for SMEs based on IoT sensors network

The main innovation in the VINIoT service is the joint use of two technologies that are currently used separately: vineyard monitoring using multispectral imaging and deployed terrain sensors. One part of the system is based on the development of artificial intelligence algorithms that are feed on the images of the multispectral camera and IoT sensors, high-level information on water stress, grape ripening status and the presence of diseases. In order to obtain algorithms to determine the state of ripening of the grapes and avoid losing information due to the diversity of the grape berries, it was decided to work along the first year 2020 at berry scale in the laboratory, during the second year at the cluster scale and on the last year at plot scale. Different varieties of white and red grapes were used; in the case of Galicia we worked with the white grape variety Treixadura and the red variety Mencía. During the 2020 and 2021 campaigns, multispectral images were taken in the visible and infrared range of: 1) sets of 100 grapes classifying them by means of densimetric baths, 2) individual bunches. The images taken with the laboratory analysis of the ripening stage were correlated. Technological maturity, pH, probable degree, malic acid content, tartaric acid content and parameters for assessing phenolic maturity, IPT, anthocyanin content were determined. It has been calculated for each single image the mean value of each spectral band (only taking into account the pixels of interest) and a correlation study of these values with laboratory data has been carried out. These studies are still provisional and it will be necessary to continue with them, jointly with the training of the machine learning algorithms. Processed data will allow to determine the sensitivity of the multispectral images and select bands of interest in maturation.

Impact of climate change on the viticultural climate of the Protected Designation of Origin “Jumilla” (SE Spain)

Protected Designation of Origin “Jumilla” (PDO Jumilla) is located in the Spanish provinces of Albacete and Murcia, in the South-eastern part of the Iberian Peninsula, where most of the models predict a severe impact of climate change in next decades. PDO Jumilla covers an area of 247,054 hectares, of which more than 22,000 hectares