The concept of terroir in viticulture

Terroir is a highly important concept in viticulture because it relates the sensory attributes of wine to the environmental conditions in which the grapes are grown. Quality hierarchy and wine style may, to a considerable extent, be explained by terroir. However, terroir is difficult to study on a scientific basis because many factors are involved, including climate, soil, cultivar and human practices, and these factors interact. The best expression of terroir is achieved when the precocity of the grapevine variety is suited to the local climatic conditions in such a way that full ripeness is reached by the end of the growing season. For the production of high quality red wines, environmental conditions should induce moderate vine vigour, either through moderate water deficit stress or through low nitrogen supply. These conditions are most frequently met on shallow or stony soils, in moderately dry climates. Regular but not excessive vine water and nitrogen supplies are needed to produce high quality white wines. However, great terroir emerges only when socio-economic conditions are favourable to the establishment of quality-orientated wine production.