Terroir 1996 banner
IVES 9 IVES Conference Series 9 Bench terraces, agricultural practices and viticultural zoning in Ribeira Sacra (Galicia, Spain).

Bench terraces, agricultural practices and viticultural zoning in Ribeira Sacra (Galicia, Spain).

Abstract

L’aire d’AOC Ribeira Sacra s’étend sur plus de 200 km au large des versants escarpés du Miño et du Sil, dans la Galice (Espagne). C’est une région viticole avec des caractéristiques bien particulières que complique leur zonage viticole. Elle est désormais une région dans laquelle les vignobles sont placés sur les versants fortement inclinés (parfois la pente est supérieure à 60% ), aménages en terrasses très étroites (les gradins n’ont souvent pas plus d’un mètre de large) avec des murs en pierres sèches qui ont derrière eux au moins un bon millénaire d’existence. Ces terrasses constituent un exemple remarquable de formations anthropiques très efficaces au point de minimiser l’érosion du sol et de conduire à formation de microclimats particulièrement adaptés aux besoins de la vigne.
Par leurs caractéristiques on peut parler de véritables anthrosols et d’un zonage initial lié au procès de construction des terrasses. Du point de vue pédologique la région est bien homogène, même s’il y a quelques variations en raison des conditions particulières d’orographie, de la nature de la roche-mère (granites, gneiss, ardoises), des facteurs locaux d’exposition (de l’ouest à sud-est), de l’altitude (200 à 450 m) et, surtout, des façons de concevoir la gestion de la fertilité chimique des sols viticoles.
D’un côté, il y a des vignes où l’entretien du sol est fait selon la manière traditionnelle, avec des apports épisodiques d’engrais végétaux : ainsi, dans de nombreux vignobles, on se contente d’épandre en couverture après la vendange, un mélange de fumier, de bois de taille, de marcs de raisin et de quelques touffes de genêts ramassées dans la lande. Le plus souvent dans ces vignobles prédominent les sols avec des teneurs en matière organique élevées (même si la matière organique est très stable et sa vitesse d’évolution est lente), sols acides et riches en aluminium échangeable (l’aluminium est souvent le plus abondant parmi les cations échangeables), à faible taux de saturation de la capacité d’échange, pauvres en potassium et avec des teneurs élevées en cuivre assimilable.
Par contre, dans le cas des vignes mieux cultivées et, surtout, dans les nouvelles plantations et les replantations, l’emploi des engrais minéraux et des amendements calciques et magnésiens est très répandu. C’est dans ces vignobles que l’on trouve des sols avec un pH neutre ou légèrement acide, une teneur en matière organique plus faible, une capacité d’échange de cations effective (CECe) plus élevée; le calcium -parfois le magnésium- sont les cations échangeables le plus couramment présents sur le complexe d’échange.
En conclusion, dans les vignobles de l’ AOC Ribeira Sacra, on peut parler d’un zonage initial associé à l’aménagement en terrasses et sur lequel se superpose un deuxième zonage (plus important au point de vue des caractéristiques chimiques des sols et du potentiel qualitatif des raisins), fonction des façons d’entretien du sol.

The particular characteristic of the Ribeira Sacra OAC in Galicia (Spain) makes complicate their viticultural zoning. In this region, vineyards are cultivated in narrow bench terraces (1 m width) on slopes up to 60%. Men along the last eight centuries, playing an important role as an effective conservation practice to prevent soil erosion, have constructed these. This practice produced an important thickening of soils, providing the development of vineyards in zones, which are characterised by their adequate microclimate.
The parent geologic materials are gneiss, granite and slate, the azimuth of the hill slopes is from south to southeast and their altitude range is from 200 to 450 m above Mediterranean Sea level. Men activities may be considered as the most important forming factor. In fact, agricultural practices acting during all this time are the most important forming factor of these soils. We observed an initial zoning of these soils derived from human activities. Furthermore, we consider that these practices correspond with the requirements of the Anthrosol FAO soil unit.
The traditional management practices that still being used include organic fertilisation and .amendment and manual cultivation up to 40 cm depth. Most relevant physicochemical properties are low pH in water and in KCI saturation extracts, high organic mater contents (with low mineralisation rate), and low base saturation percentage in the cation exchange complex, and high exchangeable aluminium and assimilable copper contents. Other farmers use lime as amendment and inorganic fertilisation that increase pH and cation exchange capacity values, and diminution of organic mater and assimilable copper content.

DOI:

Publication date: February 15, 2022

Issue:  Terroir 2002

Type: Article

Authors

José M.G. QUEIJEIRO, Eugenio L. PERIAGO, Manuel ARIAS and Benedicto SOTO

Area de Edafología y Química Agricola. FacuJtad de Ciencias de Ourense, As Lagoas s/n 32004. España

Contact the author

Keywords

Ribeira Sacra, Espagne, terrasses, entretien du sol, zonage
Ribeira Sacra, Spain, bench terraces, viticultural zoning, cultural practices

Tags

IVES Conference Series | Terroir 2002

Citation

Related articles…

Revealing the Barossa zone sub-divisions through sensory and chemical analysis of Shiraz wine

The Barossa zone is arguably one of the most well-recognised wine producing regions in Australia and internationally; known mainly for the production of its distinct Shiraz wines. However, within the broad Barossa geographical delimitation, a variation in terroir can be perceived and is expressed as sensorial and chemical profile differences between wines. This study aimed to explore the sub-division classification across the Barossa region using chemical and sensory measurements. Shiraz grapes from 4 different vintages and different vineyards across the Barossa (2018, n = 69; 2019, n = 72; 2020, n = 79; 2021, n = 64) were harvested and made using a standardised small lot winemaking procedure. The analysis involved a sensory descriptive analysis with a highly trained panel and chemical measurement including basic chemistry (e.g. pH, TA, alcohol content, total SO2), phenolic composition, volatile compounds, metals, proline, and polysaccharides. The datasets were combined and analysed through an unsupervised, clustering analysis. Firstly, each vintage was considered separately to investigate any vintage to vintage variation. The datasets were then combined and analysed as a whole. The number of sub-divisions based on the measurements were identified and characterised with their sensory and chemical profile and some consistencies were seen between the vintages. Preliminary analysis of the sensory results showed that in most vintages, two major groups could be identified characterised with one group showing a fruit-forward profile and another displaying savoury and cooked vegetables characters. The exploration of distinct profiles arising from the Barossa wine producing region will provide producers with valuable information about the regional potential of their wine assisting with tools to increase their target market and reputation. This study will also provide a robust and comprehensive basis to determine the distinctive terroir characteristics which exist within the Barossa wine producing region.

Assessing the climate change vulnerability of European winegrowing regions by combining exposure, sensitivity and adaptive capacity indicators

Winegrowing regions recognized as protected designations of origin (PDOs) are closely tied to well defined geographic locations with a specific set of pedoclimatic attributes and strictly regulated by legal specifications. However, climate change is increasingly threatening these regions by changing local conditions and altering winegrowing processes. The vulnerability to these changes is largely heterogenous across different winegrowing regions because it is determined by individual characteristics of each region, including the capacity to adapt to new climatic conditions and the sensitivity to climate change, which depend not only on natural, but also socioeconomic and legal factors. Accurate vulnerability assessments therefore need to combine information about adaptive capacity and climate change sensitivity with projected exposure to new climatic conditions. However, most existing studies focus on specific impacts neglecting important interactions between the different factors that determine climate change vulnerability. Here, we present the first comprehensive vulnerability assessment of European wine PDOs that spatially combines multiple indicators of adaptive capacity and climate change sensitivity with high-resolution climate projections. We found that the climate change vulnerability of PDO areas largely depends on the complex interactions between physical and socioeconomic factors. Homogenous topographic conditions and a narrow varietal spectrum increase climate change vulnerability, while the skills and education of farmers, together with a good economic situation, decrease their vulnerability. Assessments of climate change consequences therefore need to consider multiple variables as well as their interrelations to provide a comprehensive understanding of the expected impacts of climate change on European PDOs. Our results provide the first vulnerability assessment for European winegrowing regions at high spatiotemporal resolution that includes multiple factors related to climate exposure, sensitivity, and adaptive capacity on the level of single winegrowing regions. They will therefore help to identify hot spots of climate change vulnerability among European PDOs and efficiently direct adaptation strategies.

Adaptability of grapevines to climate change: characterization of phenology and sugar accumulation of 50 varieties, under hot climate conditions

Climate is the major factor influencing the dynamics of the vegetative cycle and can determine the timing of phenological periods. Knowledge of the phenology of varieties, their chronological duration, and thermal requirements, allows not only for the better management of interventions in the vineyard, but also to predict the varieties’ behaviour in a scenario of climate change, giving the wine producer the possibility of selecting the grape varieties that are best adapted to the climatic conditions of a certain terroir. In 2014, Symington Family Estates, Vinhos, established two grape variety libraries in two different places with distinctive climate conditions (Douro Superior, and Cima Corgo), with the commitment of contributing to a deeper agronomic and oenological understanding of some grape varieties, in hot climate conditions. In these research vineyards are represented local varieties that are important in the regional and national viticulture, but also others that have over time been forgotten — as well as five international reference cultivars. From 2017 to 2021, phenological observations have been made three times a week, following a defined protocol, to determine the average dates of budbreak, flowering and veraison. With the climate data of each location, the thermal requirements of each variety and the chronological duration of each phase have been calculated. During maturation, berry samples have been gathered weekly to study the dynamics of sugar accumulation, between other parameters. The data was analysed applying phenological and sugar accumulation models available in literature. The results obtained show significant differences between the varieties over several parameters, from the chronological duration and thermal requirements to complete the various stages of development, to the differences between the two locations, confirming the influence of the climate on phenology and the stages of maturation, in these specific conditions.

Understanding graft union formation by using metabolomic and transcriptomic approaches during the first days after grafting in grapevine

Since the arrival of Phyloxera (Daktulosphaira vitifolia) in Europe at the end of the 19th century, grafting has become essential to cultivate Vitis vinifera. Today, grafting provides not only resistance to this aphid, but it used to adapt the cultivars according to the type of soil, environment, or grape production requirements by using a panel of rootstocks. As part of vineyard decline, it is often mentioned the importance of producing quality grafted grapevine to improve vineyard longevity, but, to our knowledge, no study has been able to demonstrate that grafting has a role in this context. However, some scion/rootstock combinations are considered as incompatible due to poor graft union formation and subsequently high plant mortality soon after grafting. In a context of climate change where the creation of new cultivars and rootstocks is at the centre of research, the ability of new cultivars to be grafted is therefore essential. The early identification of graft incompatibility could allow the selection of non-viable plants before planting and would have a beneficial impact on research and development in the nursery sector. For this reason, our studies have focused on the identification of metabolic and transcriptomic markers of poor grafting success during the first days/week after grafting; we have identified some correlations between some specialized metabolites, especially stilbenes, and grafting success, as well as an accumulation of some amino acids in the incompatible combination. The study of the metabolome and the transcriptome allowed us to understand and characterise the processes involved during graft union formation.

Rapid damage assessment and grapevine recovery after fire

There is increasing scientific consensus that climate changeis the underlying cause of the prolonged dry and hot conditions that have increased the risk of extreme fire weather in many countries around the world. In December 2019, a bushfire event occurred in the Adelaide Hills, South Australia where 25,000 hectares were burnt and in vineyards and surrounding areas various degrees of scorching and infrastructure damage occurred. The ability to coordinate and plan recovery after a fire event relies on robust and timely data. The current practice for measuring the scale and distribution of fire damage is to walk or drive the vineyard and score individual vines based on visual observation. The process is time consuming, subjective, or semi-quantitative at best. After the December 2019 fires, it took many months to access properties and estimate the area of vineyard damaged. This study compares the rapid assessment and mapping of fire damage using high-resolution satellite imagery with more traditional ground based measures. Satellite imagery tracking vineyard recovery in the season following the bushfire is being correlated to field assessments of vineyard productivity such as canopy health and development, fertility and carbohydrate storage. Canopy health in the seasons following the fires correlated to the severity of the initial fire damage. Severely damaged vines had reduced canopy growth, were infertile or had very low fertility as well as lower carbohydrate levels in buds and canes during dormancy, which reduced productivity in the seasons following the bushfire event. In contrast, vines that received minor damage were able to recover within 1-2 years. Tools that rapidly and affordably capture the extent and severity of damage over large vineyard area will allow producers, government and industry bodies to manage decisions in relation to fire recovery planning, coordination and delivery, improving the efficiency and effectiveness of their response.