Nature has given man rugged, steep, rocky slopes in Valtellina, apparently unsuitable for growing crops, something which would normally cause people to abandon such an the area. However, here man has managed to turn adversity to his own advantage, by building terraces supported by dry-stone walls in order to make the slopes suitable for growing grapes.
The contours of the Rhaetian side of the valley have therefore been transformed by man, who has built more than 2,500 km of stone walls, making the Valtellina the biggest terraced vine-growing area in Italy.
The particular geographic position of the valley, bounded to the north by the Rhaetian Alps, to the south by the Orobian Prealps, to the east by the Adamello and Stelvio mountain ranges and to the west by Lake Como, shelters it from bad weather, cold winds blowing from the north and hot and humid winds from the south. We can therefore talk about a particular Valtellina microclimate. The important ventilation phenomenon caused by updrafts and downdrafts, the mitigating influence of Lake Como and heavy rainfall during storms ensure that this territory, apparently hostile to grape-growing, is actually a strong point of Valtellina viticulture.
The soil has partly resulted from the degradation of parent rock and is partly due to the filling of the terraces with other soil by Valtellina farmers over the centuries. The vineyard soil – the part of the soil that interacts with the plant root system – is certainly not homogeneous, however there are similar parameters. It has a low pH (4.0 - 5.5), an abundant soil skeleton, a strong presence of sand and it is rather shallow (even only 20-30 cm deep). The presence of organic substances and humus varies and undeniably depends on the adoption of a correct agronomic plan, the soil depth, the gradient of the mountain slope and its exposure.
Therefore, the intervention strategies adopted by each farmer are extremely important: correct liming which, without upsetting the equilibrium that has been attained, can allow a slight decrease in acidity, as well as an improved retention of microelements (otherwise lost due to eluviation), a reduced contribution of nitrogen and, only if necessary, a redistribution of potassium and phosphorous, in order to give back to the vine the substances that been taken away during harvesting and pruning.
The equilibrium between the micro-organisms that can be assimilated is satisfactory: no particular deficiencies are observed. Therefore, the district features a poor, dry soil, often in inaccessible areas. However, abundant sunshine, numerous summer storms, which prevent water stress, and all those factors that constitute our “terroir” allow the growth of several types of vines, but above all of Nebbiolo, which everyone considers to be a ‘difficult’ grape variety. Locally, the variety is called Chiavennasca, which derives from the dialect word “ciuvinasca”, meaning “the most suitable for making wine”.