VITIFOREST - Exploratory research to access the effects of trees on agroforestrybased vineyards ; VITIFOREST : Evaluation de l'impact de l'arbre agroforestier en contexte viticole.

Ce volume regroupe les textes issus du programme Casdar "Innovation et Partenariat" et "Recherche finalisée et innovation" de 2014. Il a été réalisé sous l’égide du GIS Relance Agronomique. ; Vitiforest is an exploratory project. The objectives were to assess and describe the effects of trees onthe agronomic behavior of the vine, on the microclimate, as well as on the aerial and soil biodiversity.The technical and economic aspects were also assessed. A multidisciplinary team of researchers set upvarious protocols and measurement tools at vineyard scale. The study compared six plots ofagroforestry-based vineyards from three viticultural areas in the southwest of France (Bordelais, Côtesde Gascogne et Cahors): three vineyards newly planted and three older ones (9 years old max).All the plots were measured in order to establish initial states for various parameters (aerial biodiversity,earthworms, microbial communities) and to characterise the intrinsic heterogeneity. Extra data werecollected on the three older plots, among which yield and vigor of vines, microclimatic parameters, etc.On configuration with wide tree rows, we observed a decrease in maximal temperatures on vines,particularly on days with high evaporative demand. After 9 years, the practice of having grown treesalongside vines has not impacted yield, vigor of vines or composition of grapevines. This result ispromising, but further and longer monitoring is needed.No evidence of effects on ground-surface and foliage arthropods were observed, nor on pests. For themoment, no influence on the abundance and diversity of soil microorganisms has been observed either.On the other hand, an increase in the abundance of earthworms has been shown on all tree rows. Itseems that communities of microorganisms were slightly modified due to the presence of trees.Regarding technical and economic aspects, further investigations are necessary. At this stage, it is clearthat one of the best ways to deal with the complexity of agroforestry-based vineyards resides ...