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…

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.

Modulation of berry composition by different vineyard management practices

High concentration of sugars in grapes and alcohol in wines is one of the consequences of climate change on viticulture production in several wine-growing regions. In order to investigate the possibilities of adaptation of vineyard management practices aimed to reduce the accumulation of sugar during the maturation phase without reducing the accumulation of anthocyanins in grapes, a study with severe shoot trimming, shoot thinning, cluster thinning and date of harvest was conducted on Merlot variety in Istria region (Croatia), under the Mediterranean climate. Four factors which may affect grape maturation and its composition at harvest were investigated in a two-years experiment; severe shoot trimming applied at veraison when >80% of berries changed colour (in comparison to untreated control), shoot thinning (0 and 30%), cluster thinning (0 and 30%), and the date of harvest (early and standard harvest dates). Shoot thinning had no significant impact on berry composition, despite the obtained reduction in yield per vine. Lower Brix in grapes were obtained with earlier harvest date and if no cluster thinning was applied, although at the same time a reduction in the concentration of anthocyanins in berries was observed in these treatments. On the other hand, if severe shoot trimming was applied when >80% of berries changed colour, a reduction of Brix was obtained without a negative impact on berry anthocyanins concentration. We conclude that in cases when undesirably high sugar concentrations at harvest are expected, severe shoot trimming at 80% veraison may effectively be used in order to obtain moderate sugar concentration in berries together with the adequate phenolic composition.

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.

Late season canopy management practices to reduce sugar loading and improve color profile of Cabernet-Sauvignon grapes and wines in the high irradiance and hot conditions of California Central Valley

Global warming is accelerating grape ripening, leading to unbalanced wines from fruit with high sugar content but poor aroma and colour development. Reducing the size of the photosynthetic apparatus after veraison has been shown to delay technological ripeness in cool climates, but methods have not been tested in areas with high irradiance and temperature where fruit exposure could have disastrous effects on berry composition. In this Cabernet-Sauvignon trial, we compared the application of an antitranspirant (pinolene), to severe canopy topping and above bunch zone leaf removal, all performed at mid-ripening, with an untouched control. We monitored the vines weekly by measuring stem water potential, gas exchange, fruit zone light exposure. We sampled berries to measure berry weight, total soluble solids, pH, titratable acidity, and the anthocyanin profile. At harvest, we assessed yield components, measured carbon isotope discrimination, rated sunburn on clusters, and produced experimental wines. We submitted harvest samples to metabolomic profiling through PFP-Q Exactive MS/MS and wines to sensory analysis. Application of the antitranspirant significantly reduced stomatal conductance and assimilation rate but did not affect the stem water potential. Inversely, leaf removal and topping increased water potential but did not affect leaf gas exchange. The late topping was the only treatment able to decrease sugar content (up to 2Bx), increase titratable acidity and pH, and improve anthocyanin content because of lower degradation of di-hydroxylated forms. Late leaf removal above the bunch zone increased lightning conditions in the canopy and produced the most significant damage on fruits. Yield components were not affected. This work suggests that late-season canopy management can effectively control ripening speeds and improve grapes and wines. Still, the effect on grape exposure in a critical time must be well balanced to avoid problems with the appropriate technique.