Mark Chien, Penn State University
Soil quality is considered by some to be paramount in the production of fine wines. However, grapes are grown worldwide on a wide variety of soils, and grapevines are adapted to a wide range of soil conditions. What is underfoot is an incredibly complex system that can be critical to wine quality. Vineyard soils should be evaluated in their full context – physical, chemical, and biological properties. Seek a balance of these constituent parts to accommodate the plant and climate as well as the applied viticulture. Other considerations, such as slope, aspect, and elevation  have indirect effects on soil relative to its impact on vine physiology. An ideal vineyard soil is deep, well-drained, with moderate fertility and moderate water-holding capacity. Soils that are not well drained should be carefully evaluated for potential improvement by tile drainage. Soils that are consistently wet due to impervious layers such as fragipans or clay subsoils are unsuitable for vineyards. Deep, fertile soils also pose challenges for producing premium grapes, as management of vine vigor and canopy microclimate can be difficult on such soils.
Soils for Fine Wine. Robert E. White. 2008. 2nd ed. Winetitles.
Terroir. James E. Wilson. 1998. The University of California Press.
Viticulture and Environment. John Gladstones. 1992. Winetitles.
Viticulture: Vol 2. Practices. B.G Coombes and P.R. Dry. Winetitles
Soil Biology Primer. Soil and Water Conservation Society. 2000. NRCS.
Reviewed by Eric Stafne, Mississippi State University
and Bruce Bordelon, Purdue University