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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

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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

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