Terroir 1996 banner
IVES 9 IVES Conference Series 9 Caratteristiche fisico-chimiche dei suoli coltivati a vite e loro influenza nella diffusione del mal dell’esca

Caratteristiche fisico-chimiche dei suoli coltivati a vite e loro influenza nella diffusione del mal dell’esca

Abstract

[English version below]

Il mal dell’esca é una malattia della vite della quale sono state studiate sintomatologia, eziologia, patogenesi ed epidemiologia. Essendo una malattia che colpisce soprattutto la parte epigea delle piante, le caratteristiche dei suoli non sono mai state considerate fra le responsabili della sua insorgenza e diffusione. In questo lavoro abbiamo studiato suoli di vigneti in cui il mal dell ‘esca présenta un ‘elevata incidenza e suoli di vigneti dove tale incidenza è scarsa o nulla. Le osservazioni morfologiche ed i risultati analitici indicano che i vigneti più danneggiati dalla malattia sono quelli i cui suoli presentano condizioni idromorfe a minima profondità, fra i 35 ed i 65 cm. Al contrario, i terreni dove l’incidenza é scarsa non presentano segni di idromorfia.
La difficoltà di percolazione, con conseguente instaurarsi di condizioni asfittiche, può essere imputata a due cause: 1) diminuzione di porosità totale negli orizzonti inferiori e 2) preponderante presenza di microporosità dovuta all’eccessivo contenuto di argilla e limo (dal 48 al 76%). Inoltre, l’argilla è costituita da minerali in grado di espandersi in presenza di acqua e, quindi, di rallentare ulteriormente il drenaggio del suolo. Al tri fattori che favoriscono la formazione di orizzonti asfittici sono: 1) i bassi tenori di carbonio organico non sufficienti a prevenire la migrazione dell ‘argilla; 2) la scarsa efficienza delle opere di drenaggio e 3) le lavorazioni meccaniche. Nei suoli ben drenati il contenuto di argilla e limo non supera il 45%, i minerali a reticolo espandibile sono presenti in tracce e, di conseguenza, non vi sono difficoltà di percolazione. Dalle nostre osservazioni risulta quindi che i vigneti maggiormente soggetti al mal dell ‘esca sono quelli che tendono a sviluppare condizioni di scarso drenaggio.

Studies have been conducted on the symptomatology, aetiology, pathogenesis and epidemic of the esca, a disease that affects grapes. Since Esca attacks mostly the above ground parts of the plants, the soil has not been considered relevant in the development and spreading of this disease. In this work we have investigated vineyard soils with a high incidence of esca, and others with a low or no incidence. Our morphological observations and analyses have shown that those vineyard affected by esca also manifest poorly drained conditions at a depth of about 35-65 cm. On the contrary the soils where the occurrence of the disease is less manifested are well drained.
The irnpeded drainage, with the attendant unoxy conditions, can be attributed to two causes: 1) a decreasing porosity in the lower horizons and 2) the prevailing micro porosity due to the high content of clay and silt (from 48 to 76%). Moreover, the clay is made of minerals that, once hydrated, tend to expand, further reducing the porosity and, thus, the drainage. Others factors that additionally cause a deterioration of the drainage are 1) the low organic matter content that prevent aggregation; 2) the inadequate drainage structures and 3) the continuous mechanical operations. In the well-drained soils the clay plus silt content is always less than 45%, the expandable minerals are presence in traces and, hence, there are not limitations to impede the drainage. We conclude that the vineyards more vulnerable to the esca are those painted on soils which tend to develop poorly drained conditions.

DOI:

Publication date: March 2, 2022

Issue: Terroir 1998

Type: Article

Authors

GIUSEPPE CORTI, FIORENZO C. UGOLINI, ROSANNA CUNIGLIO

Dipartimento di Scienza del Suolo e Nutrizione della Pianta
Piazzale delle Cascine, 15 – 50144 Firenze

Tags

IVES Conference Series | Terroir 1998

Citation

Related articles…

Spatial determination of areas in the Western Balkans region favorable for organic production

In problematic conditions for production of grapes and wine caused by the COVID-19 pandemic and the resulting occurrence of wine surpluses, producers are increasingly turning to the innovative viticulture and winemaking of products that are more appealing to the market and the consumers. On the other hand, consumption of the food safety or organic products, and therefore of organic grapes and wine, is increasingly common in the world, in particular in Europe. The Regional Rural Development Standing Working Group (SWG RRD), as a regional intergovernmental organization gathers actors in the viticulture and winemaking sector from states and territories of the Western Balkans (South-East Europe) in the Expert Working Group for Wine, with the aim of improving viticulture and winemaking in this region through joint activities. In accordance with the aforementioned, the SWG RRD is working on advancing organic production of grapes and wine, and on recognition of specificities of the terroir of wine-growing areas in Western Balkans. In addition, as part of the project “Facilitation of Exchange and Advice on Wine Regulations in Western Balkan Countries” helmed by the German Federal Ministry of Food and Agriculture, in addition to harmonization of relevant legislation with EU regulations, efforts are being invested towards recognition of organic wines. Within activities and project implemented by this organization, expert analyses and scientific research of the terroir of Western Balkans were carried out, and some of the results are presented in this paper.

Legacy of land-cover changes on soil erosion and microbiology in Burgundian vineyards

Soils in vineyards are recognized as complex agrosystems whose characteristics reflect complex interactions between natural factors (lithology, climate, slope, biodiversity) and human activities. To date, most of the unknown lies in an incomplete understanding of soil ecosystems, and specifically in the microbial biodiversity even though soil microbiota is involved in many key functions, such as nutrient cycling and carbon sequestration. Soil biological properties are indicative of soil quality. Therefore, understanding how soil communities are related to soil ecosystem functioning is becoming an essential issue for soil strategy conservation. Here, we propose to assess the importance of land-cover history on the present-day microbiological and physico-chemical properties. The studied area was selected in the Burgundian vineyards (Pernand-Vergelesses, Burgundy, France) where land occupation has been reconstructed over the last 40 years. Soil samples were collected in five areas reflecting various land cover history (forest, vineyards, shifting from forest to vineyards). For each area, physico-chemical parameters (pH, C, N, P, grain size) were measured and DNA was extracted to characterize the abundance and diversity of microbial communities. The obtained results show significant differences in the five areas suggesting that present-day microbial molecular biomass and bacterial taxonomic is partly inherited from past land occupation. Over longer period of time, such study of land-uses legacies may help to better assess ecosystem recovery and the impact of management practices for a better soil quality and vineyards sustainability.

Soil, vine, climate change – what is observed – what is expected

To evaluate the current and future impact of climate change on Viticulture requires an integrated view on a complex interacting system within the soil-plant-atmospheric continuum under continuous change. Aside of the globally observed increase in temperature in basically all viticulture regions for at least four decades, we observe several clear trends at the regional level in the ratio of precipitation to potential evapotranspiration. Additionally the recently published 6th assessment report of the IPCC (The physical science basis) shows case-dependent further expected shifts in climate patterns which will have substantial impacts on the way we will conduct viticulture in the decades to come.
Looking beyond climate developments, we observe rising temperatures in the upper soil layers which will have an impact on the distribution of microbial populations, the decay rate of organic matter or the storage capacity for carbon, thus affecting the emission of greenhouse gases (GHGs) and the viscosity of water in the soil-plant pathway, altering the transport of water. If the upper soil layers dry out faster due to less rainfall and/or increased evapotranspiration driven by higher temperatures, the spectral reflection properties of bare soil change and the transport of latent heat into the fruiting zone is increased putting a higher temperature load on the fruit. Interactions between micro-organisms in the rhizosphere and the grapevine root system are poorly understood but respond to environmental factors (such as increased soil temperatures) and the plant material (rootstock for instance), respectively the cultivation system (for example bio-organic versus conventional). This adds to an extremely complex system to manage in terms of increased resilience, adaptation to and even mitigation of climate change. Nevertheless, taken as a whole, effects on the individual expressions of wines with a given origin, seem highly likely to become more apparent.

Revealing the Barossa zone sub-divisions through sensory and chemical analysis of Shiraz wine

The Barossa zone is arguably one of the most well-recognised wine producing regions in Australia and internationally; known mainly for the production of its distinct Shiraz wines. However, within the broad Barossa geographical delimitation, a variation in terroir can be perceived and is expressed as sensorial and chemical profile differences between wines. This study aimed to explore the sub-division classification across the Barossa region using chemical and sensory measurements. Shiraz grapes from 4 different vintages and different vineyards across the Barossa (2018, n = 69; 2019, n = 72; 2020, n = 79; 2021, n = 64) were harvested and made using a standardised small lot winemaking procedure. The analysis involved a sensory descriptive analysis with a highly trained panel and chemical measurement including basic chemistry (e.g. pH, TA, alcohol content, total SO2), phenolic composition, volatile compounds, metals, proline, and polysaccharides. The datasets were combined and analysed through an unsupervised, clustering analysis. Firstly, each vintage was considered separately to investigate any vintage to vintage variation. The datasets were then combined and analysed as a whole. The number of sub-divisions based on the measurements were identified and characterised with their sensory and chemical profile and some consistencies were seen between the vintages. Preliminary analysis of the sensory results showed that in most vintages, two major groups could be identified characterised with one group showing a fruit-forward profile and another displaying savoury and cooked vegetables characters. The exploration of distinct profiles arising from the Barossa wine producing region will provide producers with valuable information about the regional potential of their wine assisting with tools to increase their target market and reputation. This study will also provide a robust and comprehensive basis to determine the distinctive terroir characteristics which exist within the Barossa wine producing region.

Analysis of some environmental factors and cultural practices that affect the production and quality of the Manto Negro, Callet and Prensal Blanc varieties

45 non irrigated vineyards distributed in the DO (Denomination) Pla i Llevant de Mallorca and the DO Binissalem Mallorca were used to investigate the characteristics of production and quality and their relationships certain environmental factors and cultural practices. The grape varieties investigated are autochthonous to the island of Mallorca, Manto Negro and Callet as red and Prensal Blanc as white. All plants were measured for four consecutive years in the main production and quality parameters. Among the environmental factors, the type of soil has been studied, more specifically its water retention capacity, the planting density, the age of the vineyard and the level of viral infection. The presence or absence of virus seems to have no effect on any component studied in the varieties studied. For the white variety Prensal Blanc age is negatively correlated with production and the number of bunches, nevertheless it does not cause any effect on the required quality parameters. However, for the red varieties Callet and Manto Negro, the age of the plantation is the variable that best correlates with the quality parameters, therefore the old vines should be the object of preservation by the viticulturists and winemakers in order to guarantee its contribution to the quality of the wines made with these varieties.