Agriculture Reference
In-Depth Information
Great Soil Group Soils and World Soil Classes
Relevant to Viticultural Regions of the World
Appendix 1
Classes at the highest level in a soil classification are the most inclusive. These
classes are based on a central concept that broadly encompasses members of the
class. Each defining concept may be based on a factor of soil formation, such as
parent material or climate, on a pedogenic process, or on an easily observed soil
property or set of properties.
The Great Soil Group Classification was developed from Russian studies of
soil formation, which particularly emphasized the role of climate and vegetation
on pedogenic processes. The classification underwent many revisions during the
twentieth century, with one of the latest versions being published by Stace et al.
(1968). Relatively little use has been made of the higher categories of Order and
Suborder. The intermediate level of Great Soil Groups (which gives the classifi-
cation its name) has proved most popular. A similar approach underlies the de-
velopment of soil classes (soil units) in the Soil Map of the World (FAO-Unesco
1988). The soil units are mapped as associations at a scale of 1:5,000,000. The
units have been grouped into 28 World Soil Classes on the basis of the inferred
pedogenic processes such as gleying (section 1.3.3.2), salinization (7.2.2), and lessi-
vage (section 1.3.2.1), which have relevance to soil use and management.
In table A1.1, the soils commonly used for viticulture in different parts of
the world are identified within their Great Soils Groups and cross-correlated with
a World Soil Class where possible. The underlying connotation or inferred pe-
dogenic process is also briefly described.
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