4,674 research outputs found
The interplay between grape ripening and weather anomalies in Northern Italy – A modelling exercise
No full textCurrent climate change is increasing inter- and intra-annual variability in atmospheric conditions leading to grapevine phenological shifts as well as altered grape ripening and composition at ripeness. This study aims to i) detect weather anomalies within a long-term time series, ii) model grape ripening revealing altered traits in time to target specific ripeness thresholds for four Vitis vinifera cultivars, and iii) establish empirical relationships between ripening and weather anomalies with forecasting purposes. The Day of the Year (DOY) to reach specific
grape ripeness targets was determined from time series of sugar concentrations, total acidity and pH collected from a private company in the period 2009–2021 in North-Eastern Italy. Nonlinear regression models were fitted over a time series of ripening parameters on a calendar time basis and assessed for modelling efficiency (EF) and error of prediction (RMSE) in four grapevine cultivars (Merlot, Cabernet-Sauvignon, Glera and Garganega). For each vintage and cultivar, advances or delays in DOY to target specified ripeness thresholds were assessed with respect to the average ripening dynamics. A thirteen years’ long meteorological series monitored at a ground weather station using hourly air temperature and rainfall data was analysed. Climate statistics were obtained and for each time interval (month, bimester) weather anomalies were identified. A linear regression analysis was performed to assess correlations between ripening and weather anomalies. For each cultivar, ripeness advances or delays expressed in the number of days to target the specific ripening threshold were assessed in relation to registered weather anomalies and the specific reference time interval in the vintage. Precipitation of the warmest month and temperature anomalies during late spring (May–June) and during the warmest month (August) we found to be important to understanding the effect of climate change on sugar ripeness. Maximum and minimum temperatures of the May–June bimester and maximum temperatures of the warmest month best correlate with altered total acidity evolution and pH increment during the ripening process. A new modelling framework is presented using historical data that supports management decisions by better understanding past impacts and forecasting for the future
Bilanci di energia, acqua e carbonio del vigneto: un approccio multi - scala
No full textThe research, carried out in 2006 and 2007, concerned the dynamics of the key physiological processes in a vineyard of the Venetian Region. The study allowed a detailed characterization of the energy, hydrological and carbon budget of the vineyard.
The measurements have been conducted at different spatial and temporal scales from the leaf, to the canopy, and up to whole the vineyard.The measurements at leaf scale permitted the parameterization of the Farquhar model of photosynthesis to interpret the physiological response of the leaf to the different environment variables. The continuous monitoring of energy and mass fluxes performed during the two years using the eddy covariance micrometeorological technique, has been used to assess the energy balance, the actual evapotranspiration, and the Net Ecosystem Exchange of the vineyard at the plot scale. A further up-scaling has been carried out using remote sensing techniques, in order to study the possibility of regionalization of the physiological processes measured at lower scales. Detailed biometrical measurements were collected during the same growing seasons, to compare the trend of the growths and carbon allocation in the different parts of the vineyard and validate the overall budget.
The adopted multi-scale approach allowed to collect unique dataset, useful to get a clear picture of the energy balance, mass exchange, and growth processes of the vineyard, and a good agreement between the different scales explored was achieved. The carbon budget, assessed and cross-validated at different scales, underlines the role of the vineyard as a possible sink of CO2, in contrast with most of the agricultural crops. A positive sink activity of the vineyard, even taking into account the harvested dry matter, can add a further environmental value to Viticulture
Carbon budget of the vineyard – A new feature of sustainability
No full textVineyards received scarce attention in relation to the continuous monitoring of carbon fluxes and the assessment of their overall budget, as a common believe is that agricultural crops cannot be net carbon sinks. Indeed, many technical inputs, massive periodical harvests, and the repeated disturbances of upper soil layers, all contribute to a substantial loss both of the old and newly-synthesized organic matter. Woody perennials, however, can behave differently: they grow a permanent structure, stand undisturbed in the same field for decades, originate abundant pruning debris, and are often grass-covered. We have been monitoring the Net Ecosystem Exchange (NEE) by eddy covariance and the carbon partitioning in a temperate vineyard in North Eastern Italy.
Five complete yearly budgets confirm a steady and substantial sink capacity of the system, with a yearly NEE around 800–900 gC m−2, grape harvest representing about 20–25% of it. Biometrical assessment of growth and partitioning show a good agreement with micrometeorological measurements and demonstrate a large input of organic matter into the soil. Even if it can be objected that this sink may be only temporary and the built-up can be substantially disrupted at the end of the vineyard life cycle, these results show that there is a concrete possibility of storing carbon in temperate-climate vineyards, possibly contributing to the global carbon budget. This sink capacity might be accounted in the official calculation of wine carbon footprint and represents a new,
relevant feature of their sustainability
Comparison of MODIS-based evapotranspiration estimates with eddy covariance measurements on a vineyard in North-Eastern Italy
No full textStima dei flussi di evapotraspirazione e fotosintesi del vigneto mediante tecniche micrometeorologiche
No full textUse of hyperspectral data for assessing vineyard biophysical and quality parameters in Northern Italy
No full textA total of 39 study sites from 11 commercial vineyards located in two traditional growing areas of Northern Italy were identified for airborne hyperspectral acquisition in summer 2009 with the Aisa-EAGLE Airborne Hyperspectral Imaging Sensor.
Field sampling campaigns were conducted during the airborne overflights and around harvest, collectin canopy srtructural parameters, leaf and canopy biophysical characteristics as well as spectral signatures and must quality traits.
Several vegetation indices were calculated from each plot to relate variations in canopy structure and foliar pigment concentration to vine status and grape quality parameters.
The up-scaling model through TCARI/OSAVI index allowed to yield acceptable estimates of leaf chlorophyll content. However model refinements are needed to improve its capacity to taking into account understory grass cover at the highest intrument resolution
- …
