Petroargid
A representative soil profile of a Typic Petroargid from New Mexico. (Photo provided by USDA-NRCS-New Mexico.)
Typic Petroargids are the Petroargids that have a petrocalcic horizon that has its upper boundary within 150 cm of the soil surface. These soils do not have a soil moisture regime that borders on ustic or xeric. They occur in the southwestern part of the United States and in South Africa and Argentina.
Argids are the Aridisols that have an argillic or natric horizon but do not have a duripan or a gypsic, petrocalcic, petrogypsic, or salic horizon within 100 cm of the soil surface. The low water flux and high concentration of salts in many Aridisols hinder clay illuviation. The presence of an argillic horizon commonly is attributed to a moister paleoclimate, although there is evidence that clay illuviation occurred during the Holocene in arid soils. Where the soil moisture regime grades to ustic or xeric, evidence of clay translocation commonly is more readily established. Most of the Argids occur in North America. A few have been recognized in the deserts of North Africa or the Near East.
For additional information about U.S Soil Taxonomy, visit:
www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/survey/cla...
Petroargid
A representative soil profile of a Typic Petroargid from New Mexico. (Photo provided by USDA-NRCS-New Mexico.)
Typic Petroargids are the Petroargids that have a petrocalcic horizon that has its upper boundary within 150 cm of the soil surface. These soils do not have a soil moisture regime that borders on ustic or xeric. They occur in the southwestern part of the United States and in South Africa and Argentina.
Argids are the Aridisols that have an argillic or natric horizon but do not have a duripan or a gypsic, petrocalcic, petrogypsic, or salic horizon within 100 cm of the soil surface. The low water flux and high concentration of salts in many Aridisols hinder clay illuviation. The presence of an argillic horizon commonly is attributed to a moister paleoclimate, although there is evidence that clay illuviation occurred during the Holocene in arid soils. Where the soil moisture regime grades to ustic or xeric, evidence of clay translocation commonly is more readily established. Most of the Argids occur in North America. A few have been recognized in the deserts of North Africa or the Near East.
For additional information about U.S Soil Taxonomy, visit:
www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/survey/cla...