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Fourth international symposium for vitivinicultural zoning
Key words: Terroir, international symposium, viticulture
Terroir is an age-old concept, the word itself being derived from the Latin "terra". The ancients from the Egyptian, Jewish and Greek cultures accepted the important role that the vineyard site played and would name their wines, not by cultivar but by origin (Fregoni, 2002). This original denomination by origin culminated in the list of "crus" in Bordeaux in 1855 and the concept has been carried over to South Africa in our own Wine of Origin system. It is, however, no longer sufficient to rely on slow evolutions to select the prime terroirs and reject unsuitable cultivars and in 1993 the Office International de la Vigne et du Vin adopted a resolution requesting all member countries to stimulate research on viticultural zoning and on the interaction between the grapevine, wine and the environment in order to establish scientific methods for demarcation. This resulted in the first international congress on viticultural zoning in Angers in 1996. The success of this congress resulted in it becoming a biennial event with the congress of 2002 being hosted by the producers of the Rhône Valley ("Syndicat Général des Vignerons des Côtes du Rhône" and "Inter Rhône") in the Popes' Palace, Avignon, from 17 to 20 June 2002.
This congress was attended by 250 participants from 25 countries (including South Africa, Australia, California, Argentina, France, Italy, Chile) with close to 100 presentations covering topics related to present methodology used to delimit appellations, new methods being developed and the significance thereof within the framework of viticultural landscapes. The importance of multidisciplinary research was stressed with climatic, soil and plant related aspects being integrated on all levels.
One significant message was emphasised again and again; namely that the delimitation of terroirs, or zoning, and thus their qualitative characterisation, safeguards the agricultural products against increasing global banality. It protects the identity of viticultural (or agricultural landscapes), as well as protecting them from encroaching urbanisation. Zoning therefore has economic and cultural implications.
The use of the terroir concept within viticultural landscapes adds value, increasing marketability for tourism. This stresses the necessity for protection of these landscapes, especially through the use of sustainable agricultural practices and continued juridical protection.
As always the role of the producer and the cultivar-rootstock combination within the complex of terroir factors was a cause for discussion. There is no doubting that within the French appellation system the cultivation practices and vegetal material play a significant role, but to what extent should this be included within the scientific definition of terroir? This question was referred to the OIV expert group on Vitivinicultural zoning for further discussion.
As a conclusion to the congress the participants supported the resolutions that the concepts of zoning and terroir must be clearly defined, that the essential elements that must be taken into account on the level of the plant and its products must be determined and that the viticultural landscapes, which make a significant contribution to the image of the products of the grapevine, must be protected and their value enhanced.
What were the lessons learned for South Africa? On a scientific level, the important role that remote sensing can play in the generation of climatic and soil data was highlighted by many presenters. According to Van Leeuwen (2002), ca. 50% of terroir variability can be related to soil depth and water holding capacity. He suggested that to simplify soil mapping, which is time-consuming and costly, soils could be grouped according to their depth. Together with this, when soils of a large area have to be mapped at a small scale, small areas that have been mapped at a large scale can be used as reference sectors for extrapolation to the larger area. Van Leeuwen (2002) suggested that remote sensing could be used to help reduce soil-sampling density. These results must, of course, be ground-truthed. An interesting application of remote sensing was used in wind effect estimations in conjunction with relief shape and principal wind directions in order to determine microclimatic zones (Pythoud & Caloz, 2002).
Climatic studies have been used since the 19th century to characterise the viticultural potential of regions. Most of these studies have been performed on a macro-scale and based on climatic indices due to the availability of climatic data. These only give an indication of potential rather than characterising the natural parameters of a region. For terroir studies it is important to consider the influence of local topography and the surrounding landscape and the resulting effects of the complex interaction with soil type. New methodological tools can be used at this scale: the use of numerical modelling and the input of remote sensing (Seguin, 2002). The regional atmospheric modelling system used by Bonnardot and co-workers was highlighted in this exposé.
The potential effect of climate change on zoning was also raised. A European project is being initiated to determine the impact of climate change on the cultivar choice for specific areas. What are the potential impacts of climate change for South Africa?
For ecophysiological studies it is necessary that the experimental plots are completely homogenous with respect to genotype and cultural influences so that only site effects are studied. This means that they must have the same rootstock, scion clone, and similar vine age, row direction, planting density, irrigation scheduling, soil preparation, row cultivation, training and trellising and pest and disease management. At the meso-scale it is possible to monitor terroir X genotype interactions, which, as well as being useful for zoning, gives a linking point to the micro-scale, which is pertinent for physiological studies (Carbonneau, 2002). The challenge is to combine biochemical and molecular biology studies with whole vine physiology to holistically study this complex relationship. The focus areas of the Department of Viticulture and Oenology, combined with the biotechnology focus of the Institute for Wine Biotechnology, provides unique opportunities in this respect.
The zoning of vineyards based on terroir studies is a reality in the Rhône valley with segregation of harvest being practiced by co-operative cellars of the region. Vinsobres (Drôme), St. Hilaire d'Ozilhan (Gard) and Beaumes de Venise (Vaucluse) were the examples presented to congress participants.
Terroir research is a fast developing field relying heavily on advanced technology such as remote sensing and geographic information systems. This research cannot be performed by a Jack-of-all-trades but requires strong multidisciplinary teams of experts in soils, climate, viticulture, oenology and geography. The study must be flexible with respect to scale, i.e. must be able to scale up from region to farm and vice versa. Furthermore, the existing knowledge within a farming community can contribute significantly to terroir studies, both in the initial stages and in the verification of results (Letessier & Fermond, 2002).
The concept of terroir is not "wine speak", it is a scientific concept that is applicable to all agricultural products. In a presentation on the worldwide development of the "appellation d'origine controlée" concept and its extention to other products, Fanet mentioned the TRIPS agreement. Within the TRIPS agreement, there are 583 indications of agricultural products within the European Union, as far ranging as seafood, cheese, meat, beer, mineral water and baked products. These products are all dependent on the origin of the base products, which impart to them special characteristics. Results from terroir studies are applicable to any agricultural product, e.g. honey, cheese, apples. They lead to improved sustainability of practices and enhance the value of the resulting products. This was emphasised by field visits to various agricultural enterprises that have been the subject of "terroir zoning". This included the Tanche olives of Nyons, the Camargue bulls of Arles and the lavender of Sault. Within the scientific communications a study to identify natural terroir units for honey production was presented.
South Africa has offered to host the symposium in 2004. It leads each year to an exchange of ideas and reflections that affects research directions. It has, so far, been hosted by France, Italy and Spain. It will draw experts in terroir studies to our country, bringing a wealth of knowledge and expertise. It will also provide an opportunity to showcase our rich and diverse natural heritage, our magnificent viticultural landscapes and many different wine styles.
We were one of the first countries to initiate soil and climate related viticultural research in the early 1970s. It is important that we continue to make an impact in this arena.
Literature cited
Carbonneau A, 2002. Zoning methods in relation to the plant. In: Proc. IVth Int. Sym. Vitivinicultural Zoning, Avignon, France. In publication.
Fregoni M, 2002. General historical aspects of viticultural "terroirs". In: Proc. IVth Int. Sym. Vitivinicultural Zoning, Avignon, France. In publication.
Letessier I & Fermond C, 2002. The "Sigales method". In: Proc. IVth Int. Sym. Vitivinicultural Zoning, Avignon, France. In publication.
Pythoud K & Caloz R, 2002. Modelisation of the microclimatical parameters for the viticultural "terroirs" characterization of "Canton de Vaud" (Switzerland). In: Proc. IVth Int. Sym. Vitivinicultural Zoning, Avignon, France. In publication.
Seguin B, 2002. On the relationship between climate and "terroir" at different spatial scales: the input of new methodological scales. In: Proc. IVth Int. Sym. Vitivinicultural Zoning, Avignon, France. In publication.
Van Leeuwen C, 2002. Methodology for soil study and zoning. In: Proc. IVth Int. Sym. Vitivinicultural Zoning, Avignon, France. In publication.
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Victoria Carey, Department of Viticulture and Oenology, Stellenbosch University
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