Agriculture Reference
In-Depth Information
Table 4.3
Defining Characteristics of the Categories in Soil Taxonomy
Category
Definition
Functions
Potential Uses
Order
Soils having properties (marks) or conditions
resulting from major soil-forming processes that
are sufficiently stable in a pedologic sense, and
that help to delineate broad zonal groups of
soils.
Depict zones where similar soil conditions have
occurred for general understanding of global
patterns of soil resources
Establish global geographic areas within which
more specific factors and processes result in the
diversity of soils
General global/continental/regional assessment
global climate change studies
AMS: < 1:10,000,000
MSD: > 40,000
Suborder
Soils within an order having additional properties
or conditions that are major controls, or reflect
such controls on the current set of soil-forming
processes, and delineate broad ecosystem
regions.
Demarcate broad areas where dominant soil
moisture conditions generally result from global
atmospheric conditions
Delineate contiguous areas with similar natural
resource endowments
Ecosystems with distinct vegetation affinities
usually determined by limiting factor/s of soil
moisture or conditions
Demarcate areas in regions or large countries for
assessment and implementation of economic
development
Analysis of international production and trade
patterns
Priority setting for multipurpose uses of land
resources
AMS: 1:1,000,000 to 1:10,000,000
MSD: 4,000 to 40,000
Great Group
Soils within a suborder having additional
properties that constitute subordinate or
additional controls, or reflect such controls, on
the current set of soil-forming processes,
including landscape-forming processes.
To demarcate contiguous areas with similar
production systems or performance potentials
Development of strategic plans for regional
development
Basis for coordinating national resource
assessment and monitoring programs
Infrastructure development to assure equity in
development
AMS: 1:250,000 to 1:1,000,000
MSD: 250 to 4,000
Subgroup
Soils within a great group having additional
properties resulting from a blending or
overlapping of sets of processes in space or
time that causes one kind of soil to develop from,
or toward, another kind of soil:
To demarcate production land units with similar
land use and management requirements
Targeting research and development for specific
land use or cropping systems
Implementing conservation practices and
ecosystems-based assistance
Community development projects and monitoring
sustainability
Basis for diversification of agriculture and uses
of land resources
Basis for implementing environmental
management programs and modeling
ecosystem performance
AMS = 1:100,000 to 1:250,000
MSD: 40 to 250
Intergrades
the linkage to the great group,
suborder, or order level;
show
Extragrades
have sets of processes or conditions
that have not been recognized as criteria for any
class at a higher level, including non-soil
features;
The soil is considered to be the '
' member
of the class if the set of properties does not
define intergrades or extragrades.
typic
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