GEOPEDOLOGICAL CHARACTERIZATION AND CLIMATIC FRAMEWORK
Geological substrate: SANDY SANT’AGATA FOSSILI MARL; 9 million years old (TORTONIAN).
The vineyards are located on the mainly south-westerly facing part of the cru, falling within the area where the soils are partially-developed. The geological substrate is formed of alternating layers of silt- and calcium carbonate-rich marls and less calcareous, mainly coarse sand. The latter are subordinate to the prevailing marl. The area in question is to be considered as in transition between Sant’Agata Marl and Diano Sandstone, with the latter becoming gradually less present between the marly strata as the altitude drops. The presence of sandy layers facilitates the rise of aquifers that exploit the sand to move between the almost impermeable marly strata. This condition often leads to landslide movements during periods of extended rainfall.
Soil: BROWN, interposed with areas of WHITE SOIL; MEDIUM DEVELOPED.
The soil is an expression of the mix between the two formations. The predominance of marl is shown in the structure, where silt is the main element, followed by the sand inherited from the sandstone. A significant amount of clay is present (25% on average), due partly to the quantity already contained in the original marl, while the remainder has been generated over a very long period of time through alteration of the less stable minerals. Along with the reddish-brown colouring, this is evidence of the lengthy development of the soil here on Villero, facilitated by the hillside’s gentle gradient. The average depth of the soil for the area (c. 1-1.5 m) is linked to the above-mentioned conditions which have allowed for accumulation.
The combination of these factors enables the vine to benefit from an amount of humidity in the soil which is good – even in the driest periods of the year – and from a good supply of nutrients. Vigour is not excessive however, thanks to the structure that tends to generate a certain degree of compacting in spite of the percentage of sand, allowing the vine to maintain good vegetative balance.
Climate and topographical framework: SOUTH-WESTERLY aspect; 285-340 m a.s.l.; c. 15% gradient.
Villero belongs to the series of south-westerly facing slopes that branch off the main ridge of hills leading from Monforte down to Castiglione Falletto. The gentle gradients in this area combine with the presence of sandy strata amidst of the marls to place the hillside in the “dip slope” category, as is borne out by the frequency of landslide movements, facilitated by the position of the sedimentary strata which tend to slip downhill during periods of rain.
Unlike lower areas which are more subject to air stagnation, the medium altitude of the cru means there is a constant, light flow of air, while it is protected from the stronger winds to the east of the main ridge (bordering on Rocche di Castiglione), north of the hill of the Brunella cru, and south of the Mariondino ridge.
The south-westerly aspect is conducive to high afternoon temperatures and bright light, aided by the position protected from stronger winds. Along with the good availability of water through the clay and the richness of the soil, these aspects define the particular character of the cru.
By Edmondo Bonelli, naturalist