90 research outputs found
CAMBIAMENTI CLIMATICI E VITICOLTURA NEL NORD ITALIA: PROSPETTIVE DI ADATTAMENTO E MITIGAZIONE
No full textClimate change is leading to warmer temperatures and more erratic and intense precipitation patterns with future increases in frequency and intensity of extreme events, such as heat waves, heavy precipitations, hailstorm and drought spells. This will especially affect viticulture, because wine quality and style are highly dependent on local microclimate. In particular, climate change will impact on acidity to sugar ratio, the key quality parameter for grapes in sparkling wines production. This will have strong repercussions on the wine sector of north-eastern Italy, the production zone of the renowned Prosecco sparkling wine. On the other hand, the relationship is not unidirectional as agriculture influence climate changes with green houses gasses emissions during field management. For this reason, combined with the carbon removal by harvest, agricultural lands are considered a net source of carbon released in the atmosphere. Yet, tree crops have been shown to be a good C sinks in the short and medium term. Moreover, sustainable practices are often proposed as a good strategy for lowering impact of field management. But very low information is available in literature about the effectiveness of vineyard uptake on offset field emissions under sustainable management. The aims of this study followed these two research lines, to reach new information about i) real water requirement of a representative vineyard in the DOC Prosecco, variability of heat and drought stress risk in the extensive and variable Prosecco DOC related to grape quality and productivity in the different areas with a special focus on malic acid; ii) carbon footprint reliability and nitrous oxide emissions factors (EF) for organic fertilization, with a specific long term monitoring that allowed for calculate specific emissions factors, and climate impact of sustainable viticulture, with a multiannual comprehensive GHG budget of the vineyard. The average water consumption during growing season for a representative vineyard in the DOC Prosecco was about 450 mm with significant different values in irrigated and not-irrigated years but very stable inside these periods. The zoning for heat and water stress risk of DOC prosecco was able to discriminate different levels of heat and water stress in the DOC Prosecco, highlighting different features about grape quality and productivity depending on risk levels. This will provide the possibility of planning differentiated management strategies to safeguard the productivity and quality of the grapes for the different DOC areas. The analyses of high-resolution infield monitoring of nitrous oxide emission allowed to have a better picture of nitrous oxide emission in vineyard soil and to calculate robust and specific annual EF for N2O emissions for different soil and fertilizer management. It showed that standard EF included background fluxes, while organic fertilization was responsible for about half of emissions. We presented the first multi-annual study on comprehensive C balance in vineyards that shows net negative C balance of viticultural phase in organic conduction in four years with high variability in its components even for the same site, confirming that soil management is crucial for increasing carbon uptake and soil stock in orchards. Sustainable practices were shown to be potentially effective in helping the field phase to be climate neutral or even positive in tree crops. These kind of study and results are essential to drive management of tree crops trough future climate changes, with a perspective of climate neutrality thanks to low carbon agricultural models
Disentangling the carbon budget of a vineyard: The role of soil management
No full textThe environmental sustainability of viticulture can be enhanced with the application of conservative management practices (e.g. resident vegetation or cover crop on the inter-row), which can lead to an increase of soil carbon (C) sequestration. However, studies disentangling the vineyard C budget are still very scarce. In this context, comparing vineyard net ecosystem CO2 exchange (NEE) with soil fluxes is especially useful. From January 2015 to August 2016, we continuously monitored vineyard NEE with the eddy covariance method and ground CO2 fluxes with an automated chamber system in a commercial vineyard in North Eastern Italy. At the site, inter-rows are covered with resident herbaceous vegetation, however, due to low soil permeability, soil cultivation (ripping or tillage) was performed on alternate alleys in autumn and, sometimes, spring in order to improve water infiltration. Measured annual soil respiration was comparable, but lower, to values estimated by previous studies in vineyards and the net uptake of the grass cover laid in the middle of yearly C budget range reported in the literature for grasslands. At the end of the measurement period, the vineyard ecosystem showed to be a net sink of CO2, absorbing around −233 gC m−2. However, the C sequestration could have been much greater if no soil cultivation had been applied. Indeed, the ground compartment was a source of CO2, but without inter-row cultivation it could have been a net sink, with an overall vineyard C budget of about −421 gC m−2. This confirms that grass cover of the inter-rows can play an important role in the C budget of woody crops. Additionally, the pattern of C fluxes reveals that the activity of herbaceous vegetation in summer decreased well before vines, thus reducing water competition during dry periods. These results provide important information for the tuning of management practices aimed at improving the environmental sustainability of viticulture
Effects of evolving canopy structure on turbulence statistics in and above a hedgerow vineyard
No full textComparison of CO2 fluxes from eddy covariance and soil chambers measurements in a vineyard
No full textComparison of sensible heat fluxes by large aperture scintillometry and eddy covariance over two contrasting−climate vineyards
No full textMeasurements of turbulent energy fluxes between land-surface and the atmosphere are commonly carried out applying the eddy covariance (EC) method. Nevertheless, in some cases (e.g. surface heterogeneity, remote sensing or model validation), the use of a Large Aperture Scintillometer (LAS) is more appropriate. We compared LAS and EC measurements of sensible heat flux (H) over two contrasting vineyards of Southern (MIN site) and Northern (LIS site) Italy, mainly differentiating for climate (i.e. dry and humid), water management (i.e. irrigated and rainfed), and LAS setup. The relationship between H by LAS (HLAS) and by EC (HEC) was good at both sites, but with slightly higher HLAS. At MIN, where multiple EC stations were deployed, the best agreement was found with the station in the center of LAS path. Surface heterogeneity due to irrigation had different impact on HLAS depending on location of the source area. The canopy growth at LIS during the study period caused the approaching of LAS beam to the roughness sublayer, resulting in a reduction of HLAS compared to HEC. The closure of energy balance was higher (79%) at MIN and lower (64%) at LIS, but the agreement between HLAS and HEC was similar at both sites, suggesting that particular attention should be given to latent heat flux measurements by EC in order to better understand the energy balance closure issue
Evolution of turbulent flow characteristics in a hedgerow vineyard during the growing season
No full textThe characteristics of turbulent flow at the land-atmosphere interface and within plant canopies are strongly modified by the interactions with vegetation elements. However, only few experimental studies were conducted so far on the effect of changing leaf area on within-canopy turbulence statistics. This aspect is important for deciduous forests and perennial woody crops (orchards and vineyards), where the variation of leaf area is recurrent and substantial during the growing season. Increasing the understanding on canopy turbulence is fundamental to improve the parameterization of multi-layer models to predict vegetation-atmosphere exchanges. In this context, we conducted an experimental campaign in a hedgerow vineyard in North-East Italy carrying out measurements with a vertical array of 3D sonic anemometers, together with canopy structure characterization, in order to analyze the evolution of turbulent flow characteristics from a leafless canopy to full development. Additionally, the effects of wind direction with respect to rows and of atmospheric stability were analyzed. We found that the aerodynamic properties of the vineyard were not only influenced by canopy height and total leaf area, but also by the vertical distribution of leaf density, with the thickness of the mid-upper layer playing a major role in determining the canopy roughness and the mean level of momentum absorption. The characteristics of within-canopy turbulent flow became more similar to a well-defined mixing-layer type flow as foliage developed, but only for diagonal and across-row wind. In contrast, with wind parallel to rows the effect of increasing leaf density was lower and the vineyard was more similar to an open canopy. The influence of atmospheric stability was less important compared to wind direction or leaf density, except for the free convection class. Nevertheless, a variation of canopy aerodynamic parameters with stability was observed and this should be taken into account in atmospheric models
Study of the Carbon Budget of a Temperate-Climate Vineyard: Inter-Annual Variability of CO2 Fluxes
No full textAgriculture can play a positive role in the global carbon budget through reduction of emissions and increase of soil carbon sequestration. Woody crops, like vineyards, present biological, structural and management peculiarities (e.g. perennial structure, abundant pruning debris, inter-row cover cropping), which allow to potentially sequester a significant amount of CO2. However, only few studies have been conducted over this kind of ecosystems. In this paper, we present results from a long-term study running in North Eastern Italy on the carbon budget of a vineyard (cv Sauvignon Blanc, Guyot pruned, VSP trellised, with grass-covered alleys). We used the eddy covariance technique to continuously monitor the net ecosystem CO2 exchange (NEE), and here we analyze the first three years of measurements (May 2014 to April 2017). The vineyard showed to act as a moderate carbon sink, with an average annual net carbon uptake of 134 gC/m2. However, the inter-annual variability of NEE was considerably high and environmental conditions during vine growing season showed to have a strong impact. The summer of 2014 was characterized by plenty of rainfall and the annual carbon uptake was the highest (207 gC/m2). On the contrary, in 2015, several heat waves reached the area and the annual carbon uptake decreased to 69 gC/m2. Elevated air temperature and low soil moisture in summer significantly reduced net carbon flux in the period of the year when the activity of the vineyard is at its maximum. Nevertheless, we showed that the vineyard can behave as carbon sink on the medium-long term, and we suggest this should be taken into account in agricultural and environmental policies, complementing standard Life Cycle Assessment of the wine production chain
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