Vulnerability of vineyard soils to compaction: the case study of DOC Piave (Veneto region, Italy)

The mechanization of pruning and harvesting in vineyards has increased the risk of soil compaction. To reclaim soil properties or avoid this degradation process, it is crucial to properly manage the soil organic matter, and the application of compost derived from the vines themselves is a strategy to achieve this. The objective of this study was to evaluate the properties of soil treated with different doses of compost applied both on the vine row and the inter rows of a Vitis vinifera crop.

The SCL laboratory in Bordeaux is one of the two official control laboratories for wine and wine products in france, under the authority of the ministry of finance and two of its general directorates: the DGCCRF (directorate general for competition, consumer affairs and fraud control) and the DGDDI (directorate general of customs and excise duties). In this capacity, it verifies the regulatory compliance of wines and investigates any possible falsifications or fraud. Steviol glycosides are natural sweeteners that are not authorized as additives in wine.

Climate transition with frequent heat waves and long drought periods threatens grapevine productivity and wine quality in the Mediterranean regions. Microorganisms are known to contribute to plant fitness and to stimulate plant resilience against biotic and abiotic factors.
In this work, it was assessed the impact of long-term drought on soil microbiome associated to grapevine in open field in Alentejo, renowned Portuguese wine region.
Soil and plant tissues of drought tolerant Syrah cultivar exposed to three irrigation levels (100%- FI, 50%-DI ETc; rain-fed–NI) for 5 years were sampled for two years (2022-2023). Metabarcoding analysis of soil bacteria (16S V4 rRNA) and fungi (ITS sub-region) were integrated with soil physiochemical properties and leaves´ physiological data. Pre-dawn leaf water potential and stomatal conductance confirmed the imposed drought scenarios. Even though, α- and β-diversity of prokaryotic and eukaryotic microbial communities differed more by season than water availability, samples clustered according to soil water content and pH (p<0.05). Fungal communities show higher differences in the structure across treatments than bacteria. In 2023, 16 bacterial against 61 fungal ASVs were significatively different in abundance between NI and FI. Beijerinckiaceae, Bradyrhizobiaceae (Alphaproteobacteria) and Nocardioidaceae, Streptomycetaceae (Actinobacteria) families resulted to be significatively more abundant in NI, while Ascomycota, Basidyomicota and Mortierellomycota are the most important fungal phyla in NI. With culturomics data, this study aims to gather insights into how soil microbiome is remodelled under drought and contribute to select bacterial and fungal taxa with potential to mitigate drought stress in vineyards.

Polyphenols are important compounds involved in many chemical and sensory wine features. In winemaking, adding oenological tannins claims to have positive impacts on wine stability, protection from oxidation and aroma persistence. Polyphenols are antioxidant compounds by either scavenging reactive oxygen and nitrogen species or chelating Fe2+ ions (1). However, as tannins oxidation leads to the formation of highly reactive species (i.e. ortho-quinones), it is still unclear if they have an effective role toward oxidation of wine aromas (2). In this work, we aim at studying the effect of two commercial tannins (proanthocyanidins, ellagitannins) on red wine flavour (mainly aroma) before and after air exposition.

A critical aspect of wine quality from a consumer perspective is the overall impression of wine flavour, which is formed by the interplay of volatile aroma compounds, their precursors, and taste and matrix components. Grapes contribute some potent aroma compounds, together with a large pool of non-volatile precursors (e.g. glycoconjugates and amino acid conjugates). Aroma precursors can break down through chemical hydrolysis reactions, or through the action of yeast or enzymes, significantly changing the aroma profile of a wine during winemaking and storage. In addition, glycoconjugates of monoterpenes, norisoprenoids and volatile phenols, together with sulfur-conjugates in wine, provide a reservoir of additional flavour through the in-mouth release of volatiles which may be perceived retro-nasally.