The importance of soil characteristics

The emergence and recent focus upon organically certified wine production has contributed to a reassessment of soil characteristics as an important element in new vineyard selection. Compared with the primary status afforded to climate, soil has been frequently neglected or rather taken for granted by a large section of the industry.

One of the general rules for vineyard selection is to avoid deeply fertile soils. While these are often responsible for supporting valuable remnants of very old vines, they can be inappropriate for establishing new plantings and maintaining the healthy development of commercially productive rows. The soil profile becomes increasingly relevant in cooler regions where surface evaporation is less effective.

In the European tradition, a majority of cool climate vineyards were established on marginal soils with a limestone or calcite base. These provide excellent drainage characteristics and the capacity to warm quickly during the early growth phases of Spring. Without the capacity to warm quickly, heavier soils will prevent the roots from exiting their dormant status. This in turn delays the hormonal signals which enable vines to transition from vegetative to reproductive growth.

French vignerons are particularly adept at identifying the significant characteristics of soil, often extending to tiny parcels of land with their uniquely distinguishing “terroir” which incorporates the complex interaction of altitude, aspect, climate and soil properties. While cool climate regions of southern hemisphere viticulture may lack the extended history of observation and analysis accessible to growers in Burgundy or Champagne, there is growing awareness of soil and its contribution to the underlying quality of the harvest.