Soil parameters impact the vine-fruit-wine continuum by altering vine nitrogen status

Abstract

Aims: A three-year study was conducted in the Vaud vineyards of Switzerland to evaluate the effects of « terroir » on the ecophysiology and fruit composition of Vitis vinifera L. cv. Doral (a white variety) and the characteristics of the produced wine.

Methods and results: The impact of soil on the vine-fruit-wine continuum was evaluated at 13 sites during three seasons. Except for soil, the vineyards presented almost identical climatic characteristics and used similar cultivation techniques. We monitored the nitrogen status of the vines by measuring yeast assimilable nitrogen (YAN) in the must. The soil modulated vine nitrogen status by its fertility and rooting depth. Low vine nitrogen status induced a high soluble solid content, low malic acid content, and high pH in fruits and resulted in small berries and low vine vigour. Wines were produced in a standardised manner from each site; then, they were subjected to sensory and chemical evaluation. YAN in musts was the parameter that best explained the variation in wine sensory characteristics. Wines made from grapes with low YAN values had negative sensory characteristics such as astringency and low aromatic complexity.

Conclusion: This work provided evidence of how soil can influence fruit composition and the sensory attributes of wine. Vine nitrogen status in relation to soil characteristics was a key parameter contributing to the terroir effect.

Significance and impact of the study: This study focuses on the whole vine-fruit-wine continuum and uses scientific rigour to investigate the terroir effect over a number of vintages. Key words: terroir, vine nitrogen status, soil effect, wine quality, vinefruit- wine continuum