La qualité des sols : associer perceptions et analyses des scientifiques et des viticulteurs

French. Ce travail s’inscrit dans un projet de recherche visant à proposer aux viticulteurs un outil d’évaluation de la qualité de leurs sols, afin qu’ils puissent adopter des itinéraires culturaux plus respectueux de l’environnement. Dans le but d’accroître la transférabilité de cet outil, il est nécessaire de mieux connaître quelle(s) définition(s) les viticulteurs donnent de la qualité des sols et quels moyens ils utilisent pour l’évaluer. Pour répondre à ces questions, une enquête par entretien compréhensif a été réalisée auprès de 29 viticulteurs de 4 zones différentes du Languedoc-Roussillon (sud de la France). L’enquête a montré que les registres de la qualité des sols évoqués par les viticulteurs rappellent en de nombreux points les définitions proposées par les scientifiques, mais qu’ils ne s’y superposent pas. L’étude des indicateurs utilisés par les viticulteurs a également révélé le besoin d’outils diversifiés, performants et opérationnels pour évaluer la qualité des sols.

English. This project is part of a more ambitious research project dealing with the evaluation of the soil quality by wine-growers in order to incite them to adopt more environmentally friendly practices. In the present article, we analysed the definitions and the indicators of soil quality they use. Such approach is particularly important to highlight the bottleneck reducing the chances of new soil quality indicators adoption by wine-growers. In order to answer these questions semi-structured interview were conducted with 29 wine-growers from 4 different areas of Languedoc-Roussillon (South of France): Montagnac (Hérault), Aigues-Mortes (Gard), Vergèze (Gard) and Saint-Hippolyte du Fort (Gard). The interviewed wine-growers used different agricultural practices, mainly soil management and fertilization, under conventional or organic viticulture. As main results, we have first identified 4 types of discourses on soil quality. Wine-growers described their soil as (i) a production tool (Production lexicon), (ii) a tank with physical and chemical properties (Physico-chemical lexicon), (iii) a living system to protect (Living system lexicon) and (iv) a component of Terroir (Terroir lexicon). Interestingly, the scientists’ perceptions of soil quality were very close to the wine-growers’ ones. However, conceptions of the environment protection seemed more limited and local for wine-growers. In their definition of a « good » soil, wine-growers gave also more precise physical and chemical characteristics whereas scientists are usually more general. And finally, wine-growers included in the definition of soil quality the notion of Terroir. As a second result, the set of physical and chemical and biological indicators of soil quality measured in the research project was compared to those used by wine-growers. The scientists and wine-growers shared many indicators but the study of indicators used by wine-growers revealed the need of diversified, efficient and operational tools to evaluate soil quality. Finally, we have attempted to link the wine-growers’ perceptions of soil quality with their socio-economic characteristics. However, neither the age, nor the education level, nor the size of farm, nor the type of viticulture (conventional or organic) seemed to have a determinant effect. As a consequence, we have a better estimation of the knowledge gap between researchers and wine-growers which can be used to drive research projects and popularization of new soil quality indicators.