- Pedogenesis
Pedogenesis or soil evolution (formation) is the process by which
soil is created. It is the major topic of the science of pedology, whose other aspects include thesoil morphology , classification (taxonomy ) of soils, and their distribution in nature, present and past (soil geography andpaleopedology ).Climate
Climate regulates soil formation. Soils are more developed in areas with higher rainfall and more warmth.The rate of chemical
weathering increases by 2-3 times when the temperature increases by 10 degrees Celsius (18 °F).Climate also affects which organisms are present, affecting the soil chemically and physically (movement of roots).Organisms
The organisms living in and on the soil form distinct soil types. Coniferous forests have acidic leaf litter and form what are known as
inceptisols . Mixed or deciduous forests leave a larger layer of humus, changing the elements leached and accumulated in the soil, formingalfisols . Prairies have very high humus accumulation, creating a dark, thick A horizon characteristic ofmollisols .Parent Material
The rock from which soil is formed is called parent material.The main types are: eolian, glacial till, glacial outwash, alluvium, lacustrine parent material and residual parent material, or bedrock.Pedologists use the following formula for understanding soil formation:
s = f (cl, o, r, p, t, ...)
where s - soil properties; cl - regional climate; o - potential biota, r - topography; p - parent material; t - time; ... - additional variables.
ee also
*CLORPT
*Parent material
*Soil horizon
*Soil production function
*Topography References
* Buol, Stanley W., F.D. Hole and R.W. McCracken. 1997. Soil Genesis and Classification, 4th ed. Iowa State Univ. Press, Ames ISBN 0-8138-2873-2
* Hole Francis D., J.B. Campbell. 1985. Soil landscape analysis. Totowa Rowman & Allanheld, 214 p. ISBN 0-86598-140-X
* Jenny, Hans (1994) [http://www.soilandhealth.org/01aglibrary/010159.Jenny.pdf Factors of Soil Formation.] A System of Quantitative Pedology. New York: Dover Press. (Reprint, with Foreword by R. Amundson, of the 1941 McGraw-Hill publication). pdf file format.
* Pluijm, Ben van der, et al. Fall, 2005. [http://www.globalchange.umich.edu/globalchange1/current/lectures/soils/soils.html Soils, Weathering, and Nutrients] from the Global Change 1 Lectures. University of Michigan. Url last accessed on2007 -03-31
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