The threat of soil salinity: A European scale review

The importance of viticulture and of the winemaking socioeconomic sector in Europe is largely acknowledged. The most famous winemaking regions in Europe commonly present very specific environmental characteristics, where climate often plays a central role. Furthermore, given the strong influence of the atmospheric factors on this crop, climate change can significantly affect yield and wine quality under future conditions. Trends recorded in the recent past on many viticultural regions in Europe hint at an already pronounced increase in the growing-season mean temperatures. Furthermore, climate-change projections give evidence for significant changes in both the growing-season temperatures and precipitations in the next decades. Although grapevines have several survival strategies, the mounting evidence for significant climate change in the upcoming decades urges adaptation and mitigation measures to be taken by the whole winemaking sector. Short-term adaptation measures can be considered as a first protection strategy and should be focused at specific threats, mostly changes in crop-management practices (e.g., irrigation, sunscreens for leaf protection). At long term, however, a wide range of adaptation measures should be considered (e.g., varietal and land allocation changes). An overview of the current scientific knowledge, mostly concerning the European viticulture, the potential climate change impacts, and feasible adaptation measures is provided herein.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/fes3.14

An overview of climate change impacts on European viticulture

Understanding the source of soil organic carbon (SOC) in deep soil horizons and the processes influencing its turnover is critical for predicting the response of this large reservoir of terrestrial C to environmental change and potential feedbacks to climate. Here, we propose that soil burial is a globally important but greatly underestimated process contributing to the delivery and long-term persistence of substantial SOC stocks to depths beyond those considered in most soil C inventories. We draw from examples in the paleosol and geomorphology literature to identify the effects of soil burial by volcanic, aeolian, alluvial, colluvial, glacial, and anthropogenic depositional processes on soil C storage. We describe how the state factors affecting soil formation affect the persistence and decomposition of SOC in buried soils. Organic horizons and surface mineral soils that become buried under layers of sediment can store C several meters below the earth's surface for millennia or longer. Buried SOC concentrations can rival those of surface soils, and soils buried under volcanic deposits generally contain higher concentrations of SOC than those under alluvial or non-permafrost loess deposits. The dearth of quantitative research on buried SOC specifically, and on deep C pools in general, makes it difficult to estimate the global importance of burial as a terrestrial C storage mechanism on contemporary time scales. The handful of studies that provide data on soil C stocks in buried horizons and estimate their spatial extent suggest that buried soils can contain significant regional OC reservoirs that are currently ignored in inventories and biogeochemical models. Recent research suggests that these buried SOC stocks may cycle biologically on annual-to-decadal time scales if the processes contributing to their protection from decomposition are altered. We discuss the vulnerability of buried SOC pools to disturbance from climate change and human activities that may reconnect these deep SOC pools with the atmosphere. We also provide recommendations on how burial processes can be incorporated into soil biogeochemical models to more accurately predict dynamics of deep SOC pools under different landscapes and environmental conditions.

Soil burial contributes to deep soil organic carbon storage

The most abundant phenolic compounds in olive oils are the phenethyl alcohols hydroxytyrosol and tyrosol. An optimized method to quantify the total concentration of these substances in olive oils has been described. It consists of the acid hydrolysis of the aglycons and the extraction of phenethyl alcohols with a 2 M HCl solution. Recovery of the phenethyl alcohols from oils was very high (<1% remained in the extracted oils), and the limits of quantification (LOQ) were 0.8 and 1.4 mg/kg for hydroxytyrosol and tyrosol, respectively. Precision values, both intraday and interday, remained below 3% for both compounds. The final optimized method allowed for the analysis of several types of commercial olive oils to evaluate their hydroxytyrosol and tyrosol contents. The results show that this method is simple, robust, and reliable for a routine analysis of the total concentration of these substances in olive oils.

Analysis of total contents of hydroxytyrosol and tyrosol in olive oils.

Increasing consciousness regarding the nutritional value of olive oil has enhanced the demand for this product and, consequently, the expansion of olive tree cultivation. Although it is considered a highly resilient and tolerant crop to several abiotic stresses, olive growing areas are usually affected by adverse environmental factors, namely, water scarcity, heat and high irradiance, and are especially vulnerable to climate change. In this context, it is imperative to improve agronomic strategies to offset the loss of productivity and possible changes in fruit and oil quality. To develop more efficient and precise measures, it is important to look for new insights concerning response mechanisms to drought stress. In this review, we provided an overview of the global status of olive tree ecology and relevance, as well the influence of environmental abiotic stresses in olive cultivation. Finally, we explored and analysed the deleterious effects caused by drought (e.g., water status and photosynthetic performance impairment, oxidative stress and imbalance in plant nutrition), the most critical stressor to agricultural crops in the Mediterranean region, and the main olive tree responses to withstand this stressor.

https://www.mdpi.com/2223-7747/8/7/232/pdf

Drought Stress Effects and Olive Tree Acclimation under a Changing Climate.

Successful adoption of precision viticulture at the farm level depends on the appreciation of vineyard spatial variability. Knowing the spatial variability of soil properties is a challenge, often very expensive and labor intensive. An alternative approach could be the combined utilization of proximal and remote sensors. This study combined proximal (Geonics EM38-MK2) and remote (normalized difference vegetation index, NDVI) sensing aimed at mapping homogeneous zones (HZs) of two 3.5-ha vineyards in the Chianti wine district (Italy). Two HZs in each vineyard were obtained by a k-means clustering of the first two factors of the principal component analysis performed on four maps: (i) apparent electrical conductivity, obtained by EM38-MK2 at 0 to 75 cm (ECa₁) and (ii) 0 to150 cm (ECa₂); (iii) topographic wetness index (TWI), calculated from a digital elevation model; and (iv) NDVI extrapolated by multispectral airborne images. Only ECa₁ and ECa₂ were correlated with some physical (silt and gravel content) and hydrologic (available water capacity) features of the soils. These two variables could also better discriminate the two HZs with respect to NDVI and TWI. The grapes (Vitis vinifera L.) of the selected HZs were separately harvested and vinified to test the differences in the wine quality. Significant differences emerged between the wines produced from the two HZs, especially in terms of color intensity, dry extract, and anthocyanin content. A wine tasting after 6-mo aging of the wines confirmed the differences between the wines produced in the two zones, especially in terms of color, structure, and total score.

Improving Wine Quality through Harvest Zoning and Combined Use of Remote and Soil Proximal Sensing

Mapping suitability for Sangiovese wine by means of δ13C and geophysical sensors in soils with moderate salinity

Quaternary landscape history determines the soil functional characters of terroir

The influence of climate and soil on viticultural and enological parameters of ´sangiovese´ grapevines under non-irrigated conditions

This work aimed at setting up a multivariate and geostatistical methodology to map viticultural terroirs at the province scale (1:125,000). The methodology is based upon the creation of a GIS storing all the viticultural and oenological legacy data of experimental vineyards (1989–2009), long-term climate data, digital elevation model, soilscapes (land systems) and legacy data of soil profiles.Environmental parameters related to viticulture, selected by an explorative PCA, were: elevation, mean annual temperature, mean soil temperature, annual precipitation, clay, sand and gravel content of soils, soil water availability, redoximorphic features and rooting depth.The variables interpolated using geostatistical methods, were used for a k-means clustering aimed to map the Natural Terroir Units (NTU). Vineyards of the province of Siena was subdivided into 9 NTU.Both the historical DOCG (Chianti Classico, Brunello di Montalcino and Nobile di Montepulciano) and other DOCs were characterized by three or four NTU,...

Pierluigi Bucelli

Papers

Improving Wine Quality through Harvest Zoning and Combined Use of Remote and Soil Proximal Sensing

Mapping suitability for Sangiovese wine by means of δ13C and geophysical sensors in soils with moderate salinity

Quaternary landscape history determines the soil functional characters of terroir

The influence of climate and soil on viticultural and enological parameters of ´sangiovese´ grapevines under non-irrigated conditions

Natural terroir units, Siena province, Tuscany