Paleustalf, Aridic
A representative soil profile of an Aridic Paleustalf from Arizona, USA. (Photo provided by Rob Wilson.)
These soils are like Typic Paleustalfs, but they are drier. In addition, they do not have a calcic horizon or are noncalcareous in some subhorizon above the calcic horizon, or, if calcareous throughout, the calcic horizon is deeper than 100 cm if the weighted average particle-size class of the upper 50 cm of the argillic horizon is sandy, deeper than 60 cm if the particle-size class is loamy, or 50 cm if the particle-size class is clayey. The calcic horizon is normally in the thick argillic horizon. These soils are thought to have been recalcified since the argillic horizon formed. In the United States, dust from the Aridisols to the west is a probable source of some of the carbonates. Aridic Paleustalfs are extensive in some areas in the southern part of the Great Plains. Their slopes are gentle. Many of the soils are used as cropland. Some are used for irrigated crops, mainly cotton, sorghum, and wheat. Others are used for drought-tolerant crops or for grazing.
Paleustalfs are the reddish or red Ustalfs that are on old surfaces. Many of them have some plinthite in their lower horizons. Paleustalfs occur in relatively stable landscape positions, their slopes are mostly gentle, and their genesis began before the late Pleistocene. In the United States, they typically have a Bk or calcic horizon in or below the argillic horizon as a result of additions of atmospheric carbonates. Commonly, secondary lime coats the surfaces of peds that have noncalcareous interiors and the soils may be noncalcareous at a depth of less than 200 cm. A few of these soils, near the boundary where they join Aridisols, have received enough calcareous dust to have a petrocalcic horizon. A few others, near the boundary where they join Udults or Udalfs, do not have a Bk horizon. Before cultivation, the vegetation on the Paleustalfs in the United States included a mixture of grasses and woody plants. These soils are moderately extensive in the southern part of the Great Plains in the United States, and they probably are extensive in Africa and southern Asia.
For more information about soils and the Michigan State University-Department of Geography, visit:
project.geo.msu.edu/soilprofiles/
For additional information about soil classification, visit:
www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/survey/cla...
Paleustalf, Aridic
A representative soil profile of an Aridic Paleustalf from Arizona, USA. (Photo provided by Rob Wilson.)
These soils are like Typic Paleustalfs, but they are drier. In addition, they do not have a calcic horizon or are noncalcareous in some subhorizon above the calcic horizon, or, if calcareous throughout, the calcic horizon is deeper than 100 cm if the weighted average particle-size class of the upper 50 cm of the argillic horizon is sandy, deeper than 60 cm if the particle-size class is loamy, or 50 cm if the particle-size class is clayey. The calcic horizon is normally in the thick argillic horizon. These soils are thought to have been recalcified since the argillic horizon formed. In the United States, dust from the Aridisols to the west is a probable source of some of the carbonates. Aridic Paleustalfs are extensive in some areas in the southern part of the Great Plains. Their slopes are gentle. Many of the soils are used as cropland. Some are used for irrigated crops, mainly cotton, sorghum, and wheat. Others are used for drought-tolerant crops or for grazing.
Paleustalfs are the reddish or red Ustalfs that are on old surfaces. Many of them have some plinthite in their lower horizons. Paleustalfs occur in relatively stable landscape positions, their slopes are mostly gentle, and their genesis began before the late Pleistocene. In the United States, they typically have a Bk or calcic horizon in or below the argillic horizon as a result of additions of atmospheric carbonates. Commonly, secondary lime coats the surfaces of peds that have noncalcareous interiors and the soils may be noncalcareous at a depth of less than 200 cm. A few of these soils, near the boundary where they join Aridisols, have received enough calcareous dust to have a petrocalcic horizon. A few others, near the boundary where they join Udults or Udalfs, do not have a Bk horizon. Before cultivation, the vegetation on the Paleustalfs in the United States included a mixture of grasses and woody plants. These soils are moderately extensive in the southern part of the Great Plains in the United States, and they probably are extensive in Africa and southern Asia.
For more information about soils and the Michigan State University-Department of Geography, visit:
project.geo.msu.edu/soilprofiles/
For additional information about soil classification, visit:
www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/survey/cla...