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IVES 9 IVES Conference Series 9 The use of remote sensing for intra-block vineyard management

The use of remote sensing for intra-block vineyard management

Abstract

[English version below]

L’unité de gestion technique d’un vignoble est aujourd’hui la parcelle. Néanmoins, au sein d’une même parcelle, la variabilité de l’expression végétative et de la constitution des raisins à maturité, peut être grande, en particulier à cause d’une hétérogénéité du sol. Dans une parcelle expérimentale, la surface foliaire a été deux fois plus élevée sur les placettes de forte vigueur par rapport à celles de faible vigueur. Le taux de sucres des baies a varié de 205 à 235 g/ L. Cette variabilité devrait être prise en compte dans une gestion optimale du vignoble. Des images ont été obtenues par la télédétection à haute résolution, dont les pixels représentent 100 à 200 cm2 de surface au sol. Des pixels contenant seulement de l’information du feuillage ont alors pu être isolés de l’image. A partir des données spectrales contenues dans ces photos, un indice de végétation appelé « NDVI » (Normalized Difference Vegetation Index) peut être construit pour caractériser la vigueur de la vigne. Des zones de vigueur variable ont été identifiées au sein d’une parcelle. La similitude entre les cartes du NDVI et des variables d’expression de la vigueur, démontre la faisabilité de cartographier la vigueur à l’aide du NDVI obtenu par télédétection haute résolution, et ainsi permettre d’expliquer les variations de certains paramètres qualitatifs de la vendange qui en découlent.

In vineyard management, the technical work unit is now the block. However, considerable variability can exist inside a block with regard to vegetative growth and fruit composition at ripeness, because of soil heterogeneity. In this research, vine characteristics were measured on 96 plots of a block of 0,3 ha. Leaf area was two times greater on the plots with the highest vigour compared to the leaf area on the plots with the lowest vigour. Berry sugar content varied from 205 to 235 g/L. Optimised vineyard management should take in account this variability. Variations in soil (depth, texture) can be surveyed by soil sampling and mapped. They can also be assessed more rapidly and more precisely by geophysics, a technique based on variations in soil resistance to electric current. Vine behaviour can be measured by means of physiological indicators: N-tester for vine nitrogen status, leaf water potential and carbon isotope discrimination (δ13C) for vine water status. To represent spatial variability of physiological parameters, repeated measurements are necessary on a great number of plots inside a block, making this approach very time and money consuming. Remote sensing can be considered as an interesting alternative way to map intra-block heterogeneity. In satellite pictures, one pixel represents more than one square meter on the soil. Because a vine row rarely exceeds 60 cm in width, these pixels contain both information from the vine canopy and from the soil, making them difficult to interpret. In high resolution remote sensing, pictures are taken at an altitude of approximately 300 meters. Pixels represent 100 to 200 square centimeters on the soil. Pixels containing only information from the canopy can thus be extracted from the picture. On these photographs, vine vigour can be characterised by transforming spectral data from the canopy into a vegetation index, for instance “NDVI” (Normalized Difference Vegetation Index). This approach was used in this study. Zones of variable vine vigour were identified inside a block. The high correlation between NDVI and vigour parameters demonstrates the possibility to map the vigour with the NDVI by means of high resolution remote sensing, and consequently to explain the variations of linked quality factors.

DOI:

Publication date: January 12, 2022

Issue: Terroir 2004

Type: Article

Authors

E. Marguerit (1), J.-P. Goutouly (2), C. Azais (1), S. Merino (1), J.-P. Roby (1), C. Van Leeuwen (1)

(1) ENITA de Bordeaux-UMR Œnologie Ampélologie, 1 Crs du Général de Gaulle, BP 201, 33 175 Gradignan-cedex, France
(2) INRA-UMR Œnologie Ampélologie, ECAV, 71, av. Edouard-Bourlaux, BP 81, 33 883 Villenave d’Ornon Cedex

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IVES Conference Series | Terroir 2004

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