Full text: Unavailable
Successful adoption of precision viticulture at the farm level depends on the appreciation of vineyard spatial variability. Knowing spatial variability of soil properties is a challenge, often very expensive and labour intensive. An alternative approach could be the combined utilization of proximal and remote sensors. This study proposes a practical application of proximal (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 replicated HZs in each vineyard were obtained by a k-means clustering of the first two factors of the PCA, performed on four maps: i) apparent electrical conductivity, obtained by EM38-MK2, at 0-75 cm (ECa1) and ii) 0-150 cm (ECa2); iii) topographic wetness index (TWI), calculated from the digital elevation model (DEM); iv) NDVI, extrapolated by multi-spectral airborne images. The studied variables (ECa, TWI and NDVI) were poorly or not correlated between them, with the only exception of ECa1 and ECa2. Only the ECa1 and ECa2 were correlated with some physical (silt and gravel content) and hydrological (AWC) features of the soils. These two variables could also discriminate better the two HZs, respect to NDVI and TWI. The grapes of the selected HZs were separately harvested and vinified to test the differences in the wine features and quality. The wines of the HZs were produced by the same ordinary processes, equipments and machinery of the farm cellar, and all expressed high quality. However, significant differences emerged between the wines produced in the two HZs, especially in terms of colour intensity, dry extract and anthocyanins content. A wine tasting, carried out by 12 experts after a 6-months aging of the wines, confirmed the differences between the wines produced in the two different zones, especially in terms of colour, structure and total score of the wines.