Classification, Properties, and Management of Aridisols

Introduction to Soil Horizons

	Soil horizons which have unique morphologic, chemical and mineralogic properties are called diagnostic horizons. These horizons form the foundation of soil classification in Soil Taxonomy.
	Diagnostic horizons formed at the soil surface are called epipedons. The light colored surface horizon found in most Aridisols is called an ochric epipedon. The term epipedon is derived from the Greek word epi meaning "over," and pedon meaning "soil." Ochric is derived from the Greek word ochros meaning "pale."
	Due to the low amount or absence of leaching associated with the aridic soil moisture regime, Aridisols normally have one or more subsurface soil horizons in which suspended or dissolved minerals have been deposited.
	Nine diagnostic subsurface soil horizons are important in the classification of Aridisols. These horizons have accumulations of silicate clays, sodium, calcium carbonate, gypsum or soluble salts. These horizons can also be cemented by carbonates, gypsum or silica.

Introduction to Aridic Soils | Soil Taxonomy | Introduction to Soil Horizons | The Horizons | Suborders and Great Groups | Argid Suborder | Orthid Suborder | Subgroups | Families | Non-Aridisols | Irrigation | Saline Soils | Sodic and Saline-Sodic Soils | Final Considerations

URL:http://cals.arizona.edu/OALS/soils/aridsoils/introduction.html
Last revised: 29 August 2001
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