Agriculture Reference
In-Depth Information
can be supported by empirical correlations that do not require reasons. That is, a soil may be placed
in a taxon without knowing its genesis if the theory was not a criterion of recognition. Facts
determined by precise observation, experimentation, and measurement minimize prejudicing the
future, as do empirical relationships among facts.
REFINING THE SYSTEM: “RULES OF ENGAGEMENT”
As we venture into the new millennium, there will be constant new demands for soil survey
information. As science progresses, our understanding of soils will change. Soil classiÝcation,
which is a scientiÝc reÞection of the state of the science, must change and even adapt to the new
technologies of processing information. Owners of systems must be alert and must respond to
changing needs. Some countries are in the process of developing national systems or revising their
systems. The following is a set of ideas that may be useful:
1.
Clearly state the purpose and objectives of the system.
2.
Describe and deÝne a basic unit to be classiÝed.
3.
Be clear about whether or not geographic attributes are required.
4.
Quantify and use measurable soil properties. (If temperature and moisture patterns in soils are not
soil attributes, know why not.)
5.
Understand the scientiÝc method and use it.
6.
Understand and use categories and classes correctly in a hierarchical system. There are accepted
protocols for such systems. Do not violate them without providing viable alternatives (e.g., mutually
exclusive classes vs. fuzzy set classes).
7.
Constantly evaluate classes for appropriate central concepts (within-class attributes) and boundary
limits (among class attributes).
8.
If showing concepts of order in nature, critically evaluate the bases of differentiation for categories
as meaningful cause-and-effect relationships.
9.
If showing interpretive groupings for applied objectives, deÝne the classes in terms of the inter-
pretation, and not soils per se.
10.
Do not use concepts or theories as criteria of recognition.
11.
Evaluate the criteria that are deliberately chosen to see if they show what is desired.
12.
Accept new facts and relationships as approximations of the moment.
13.
Search for failure to accommodate new facts and relationships in a classiÝcation system.
14.
Let each experience test the theory behind the system.
15.
Establish a mechanism to constantly ensure that testing of past experience will occur.
REFERENCES
Ahrens, R.J. and Arnold, R.W. 1999. Soil Taxonomy, in
Handbook of Soil Science.
M.E. Sumner, Ed. CRC
Press, Boca Raton, E-117ÏE-135.
Allen, T.F.H. and Starr, T.B. 1982.
Hierarchy: Perspectives for Ecological Complexity
. The University of
Chicago Press, Chicago.
Arnold, R.W. 1990. Soil taxonomy, a tool of soil survey, in Soil ClassiÝcation. B.G. Rozanov, Ed. Publ. Centre
for International Projects, USSR State Committee for Environmental Protection, Moscow, 94Ï111.
Arnold, R.W., Ahrens, R.J. and Engel, R.J. 1997. Trends in soil taxonomyÐa shared heritage.
Comm. Austrian
55:167Ï170.
Bartelli, L.J. 1978. Technical classiÝcation system for soil survey interpretation.
Soil Sci. Soc. Heft.
Adv. Agron
., 30:247Ï289.
Buol, S.W., Hole, F.D. and McCracken, R.J. 1980.
Soil Genesis and ClassiÝcation
. Iowa State University
Press, Ames.
Cline, M.G. 1949. Basic principles of soil classiÝcation.
Soil Sci.
67:81Ï91.
Cline, M.G. 1963. Logic of the new system of soil classiÝcation.
Soil Sci.
96:17Ï22.
