Interactions of climate, soil, and grapevines on wine and terroir

Kees van Leeuwen, Professor of Viticulture, Bordeaux University Horticulture Section seminar series, October 20, 2014 School of Integrative Plant Science Cornell University In wine production, quality and reputation have a huge impact on selling prices. The latter are highly variable, ranging from 5$ to several hundreds of dollars a bottle. Terroir is an important clue for wine quality and typicity and thus for crop value. The terroir effect deals with the impact of environmental factors, in particular soil and climate, on vine behaviour. Because soil and climate are site specific, terroir and origin are closely related concepts. Terroir expression is optimized when grapes ripen at the end of the growing season (late September or early October on the Northern hemisphere). Too early ripening results in the production of wines lacking freshness and aroma expression and too late ripening promotes green flavors and excessive acidity. Timing of ripeness is driven by temperatures, but can also be managed through the choice of the grapevine variety. Vine development and fruit composition are further influenced by water and nitrogen supply. In a deep rooting perennial species like the vine, water and nitrogen status depend on soil type and climatic factors. They can further be optimized trough management practices.