Agriculture Reference
In-Depth Information
Notwithstanding this approach to viticulture in New World countries, in
recent time winegrowers aiming at the premium end of the market have become
more focused on matching grape varieties to soil and climate and adopting winemak-
ing techniques to attain specific outcomes for their products. For established vine-
yards, one obvious result of this change is the appearance of “single vineyard” wines
that are promoted as expressing the sense of place or
terroir
. Another reflection of this
attitudinal change is the application of precision viticulture (see “Managing Natural
Soil Variability in a Vineyard,” chapter 6), whereby vineyard management and har-
vesting are tailored to the variable expression of soil and local climate in the yield and
sensory characteristics of the fruit and wine. For new vineyards, however, determin-
ing the site starts with gathering as much data as possible on
• Climate
• Soiltypesandtheirdistribution
• Availabilityofwaterforirrigation
• Potentialforpestanddiseaseattack
Together, these factors interact to determine a site's suitability for different grape
varieties and the potential profitability of the winegrower's business.
Climate
Three levels of climatic influence are recognized in viticulture:
1. The macroclimate or regional climate: largely determined by latitude
and altitude and applicable over tens of kilometers but modified by the
distance from moderating influences such as the sea or large lakes.
2. The mesoclimate or site climate: more local than the macroclimate and
primarily determined by sharp changes in altitude over short distances, as
well as by slope and aspect. An example is the difference in mesoclimate
between north- and south-facing slopes along the Rhine River in
Germany. In California, the macroclimate of the Lodi District in the
Central Valley is different from that of the Napa region, but within each
region there are several mesoclimates, depending on the distance from
San Francisco Bay or closeness to the Mayacamus and Vaca Mountains.
3. The microclimate or canopy climate: the climate within and immediately
around the vine canopy.
Various bioclimatic indices have been developed to classify the macroclimate
and help to identify the best regions for particular “cultivars”.
1
These indices are
1
Cultivar is a shorthand term for cultivated varieties.
