Terroir 2004 banner
IVES 9 IVES Conference Series 9 The role of soil water holding capacity and plant water relations in zone/terroir expression

The role of soil water holding capacity and plant water relations in zone/terroir expression

Abstract

The spatial variability in soil type and depth and water holding capacity is very high in many viticultural regions of the world. Differences in rooting depths and water extraction profiles and their seasonal dynamics add additional variability and it is extremely difficult to deduct direct causal relationships between these factors and fruit composition even within small units of climatic zones, and much less so over larger climatic trans-sects. The influence of water status on grape composition has been studied intensively for many years, yet indirect effects caused by changes in plant water status have been largely neglected. For example, vineyard sites with limited water supply will be more prone to early leaf drop causing substantial changes in the light environment of the fruit, which in itself will change fruit temperature. Additionally, there is almost certainly a different link between plant water status and fruit and wine composition for red and white cultivars and within each respective group between varieties of different geographic origin. Another unresolved problem is the coupling of soil to plant water status. Many plant water status indicators such as stem, or midday or pre-dawn (ΨPD) leaf water potential are difficult to link to quantitative soil water data. We have recently started to use the concept of total transpirable soil water (TTSW) and the fraction thereof (FTSW), originally proposed for herbaceous plants, to evaluate the coupling between soil water availability and plant water status measurements for contrasting vineyard sites. Even for soil water holding capacities over the root profiles between 380 and 100 L/m2, and a TTSW varying from 50 to 175 L/m2, respectively, we found a single common relationship between ΨPD and FTSW for all vineyards, irrespective of water extraction profiles and canopy systems (Gruber and Schultz 2004 in press). This relationship has also been proven stable across different wine regions in Europe. This system may provide a platform to better link quality parameters to plant and soil water status. Some recent results also suggest that indirect effects of changes in water supply may be more important than previously thought for fruit composition. These effects seem not restricted to changes in canopy microclimate or co-limiting factors such as nitrogen, but seem to extend to substances influencing micronutrient metabolism of yeasts, which may alter aromatic expression. It is clear and has been proven many times that water relations are important in quality formation and in the expression of terroir characters, yet it is still difficult to provide conclusive linkages between all the involved parameters.

DOI:

Publication date: January 12, 2022

Issue: Terroir 2004

Type: Article

Authors

H. R. Schultz (1,2), Bernd Gruber (1)

(1) Institut für Weinbau und Rebenzüchtung, Forschungsanstalt Geisenheim, Germany
(2) Fachbereich Weinbau und Getränketechnologie, Fachhochschule Wiesbaden, von Lade Str. 1, D-65366 Geisenheim, Germany

Contact the author

Tags

IVES Conference Series | Terroir 2004

Citation

Related articles…

Application of grape pomace and stem extracts on Vitis vinifera L. cv. Monastrell: Increased stilbene content of grapes and wines

Pomace and grape stems are the main solid organic waste from winery industries, resulting from the pressing and/or fermentation processes it is generated in large amounts in many parts of the world

How does aromatic composition of red wines, resulting from varieties adapted to climate change, modulate fruity aroma?

One of the major issues for the wine sector is the impact of climate change linked to the increasing temperatures which affects physicochemical parameters of the grape varieties planted in Bordeaux vineyard and consequently, the quality of wine. In some varietals, the attenuation of their fresh fruity character is accompanied by the accentuation of dried-fruit notes [1]. As a new adaptive strategy on climate change, some winegrowers have initiated changes in the Bordeaux blend of vine varieties [2]. This study intends to explore the fruitiness in wines produced from grape varieties adapted to the future climate of Bordeaux. 10 commercial single–varietal wines from 2018 vintage made from the main grape varieties in the Bordeaux region (Cabernet franc, Cabernet-Sauvignon and Merlot) as well as from indigenous grape varieties from the Mediterranean basin, such as Cyprus (Yiannoudin), France (Syrah), Greece (Agiorgitiko and Xinomavro), Portugal (Touriga Nacional) and Spain (Garnacha and Tempranillo), were selected among 19 samples using sensory descriptive analyses. Both sensory and instrumental analyses were coupled, to investigate their fruity aroma expression. For sensory analysis, samples were prepared from wine, using a semi preparative HPLC method which preserves wine aroma and isolates fruity characteristics in 25 specific fractions [3,4]. Fractions of interest with intense fruity aromas were sensorially selected for each wine by a trained panel and mixed with ethanol and microfiltered water to obtain fruity aromatic reconstitutions (FAR) [5]. A free sorting task was applied to categorize FAR according to their similarities or dissimilarities, and different clusters were highlighted. Instrumental analysis of the different FAR and wines demonstrated variations in their molecular composition. Results obtained from sensory and gas chromatography analysis enrich the knowledge of the fruity expression of red wines from “new” grape varieties opening up new perspectives in wine technology, including blending, thus providing new tools for producers.

Above and below–research challenges for the future of winegrape production

Grapevines interact with the climate (aboveground) and the soil (belowground), affecting the characteristics of winegrapes produced. These interactions are impacted by climate change, the erosion of biodiversity, and losses of soil organic matter (SOM).

Soil quality in Beaujolais vineyard. Importance of pedology and cultural practices

A pedological study was carried out from 2009 to 2017 in Beaujolais vineyard, to improve physical and chemical knowledge of soils. It was completed in 2016 and 2017 by the current study, dealing with microbial aspects, in order to build a reference frame for improved advice in soil management. Microbial biomass was measured on representative plots of the six most common soil types identified in Beaujolais and, for each soil type, on plots with different levels of the main impacting parameters: total organic carbon, pH, cation exchange capacity, extractable copper. A total of 59 soil samples were collected. Confirming the results of various trials carried out in Beaujolais over the past 20 years, the results of the present study showed that the soils were still alive, but exhibited a large variability of biological parameters, which appeared dependant on both pedological and anthropic factors. Therefore, a good interpretation of biological parameters and advice for vine growers must rely on a pedologically-based referential with differentiated main driving factors. For example, the control of pH is of primary importance in granitic soils and in no way organic matter addition can improve soil quality if pH is too low. Conversely, in calcareous soils, biological parameters are more directly affected by direct or indirect (cover crops for example) inputs of organic matter. The use of biological parameters, such as microbial biomass, is of great potential value to improve advice on agro-viticultural practices (soil management, fertilization, liming, etc.), basis of a sustainable wine production on fragile soils.

Comparison of the skin resistance of several grape varieties in relation to their physico-chemical properties

The purpose of this study is to compare the skin resistance (SR) of the grapes with physico-chemical propertiess using a stong dataset and multidimentional statistical analysis .
A recent study has shown the role skin resistance plays against pest invasion but skin resistance could be a useful agronomic parameter, for example in the choice of the type of winemaking, by influencing the quantity of juice during crushing and maceration.