II. DESERT SOILS
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desert loams and other arid soils. Dune sandhills are not grazed appreciably because the grass cover is thin and wind erode seriously when the
native surface is disturbed.
Desert sand-plain soils of considerable acreage exist as relics of modified
lateritic red earths. The brown to red, loose sandy surface is underlain
by a more compact sand and finally at about 1 meter, lateritic gravel. Lime
and lateritic gravel also may be found at varying depths to the surface.
Red sand-plain soils are found in the arid regions of Western Australia,
Queensland, and the Northern Territory. They are most extensive in the
latter area. These soils are grazed sparingly because of the poor coverage
of vegetation of spinifex and grasses.
Certain tablelands in Australia also may be extensively covered with
stones which represent a former, more humid era. Their desert pavement
surface is composed of broken and polished siliceous stones (Jessup,
1962). Brown-to-red loam to clay-loam textured A horizon lies below the
pavement. In the Bl, coarse-textured clay overlays a gypsiferous clay with
some lime accumulated in the lighter colored B2. The stony desert tableland soils are found on the Gibson Desert in Western Australia, in South
Australia, and the Stuart Desert extending into Queensland. They are
poorly covered with sparse shrub-type steppe vegetation of low cattle and
sheep carrying capacity (Jessup, 1951 ).
Gray-brown and red-calcareous desert soils occur extensively in the Nullarbor Plain of South and West Australia and to a certain extent in other
arid regions (Jackson, 1957). Shrubs and grasses inhabit these soils
sparsely but are little used.
Desert loams are fine-textured soils containing some lime and gypsum
and frequently show signs of salt effects. They appear in the 12- to 25-cm
rainfall areas of southern Australia and may be covered with thin layers
of sand or stones. They are sparingly grazed. Vegetation consists of
ephemeral natural herbage and perennial edible shrubs which resemble the
shrub-type steppe vegetation.
Limy soils are concentrated more on the desert fringes than in the heart
of the arid lands, whereas gypsiferous soils appear on the more arid lands.
Solonchak (salty soils) and Solonetz (sodium-affected soils) are scattered
in depressions and in soils with saline subsoils in all areas of Australia
(Downes, 1954). Because of the extensive nature of the salt-affected land
in Australia, Stephens (1961 ) suggests that the soil salinity is derived from
wind-blown ocean spray. The parent materials on which salty soils occur
cannot account for the salt accumulations observed.
A wide variety of desert soils are found in Australia. Sandy and stony
soils are extensive and clay and loams are interspersed throughout the arid
region as are salt-affected soils. Vegetation is sparse mostly because of
87
desert loams and other arid soils. Dune sandhills are not grazed appreciably because the grass cover is thin and wind erode seriously when the
native surface is disturbed.
Desert sand-plain soils of considerable acreage exist as relics of modified
lateritic red earths. The brown to red, loose sandy surface is underlain
by a more compact sand and finally at about 1 meter, lateritic gravel. Lime
and lateritic gravel also may be found at varying depths to the surface.
Red sand-plain soils are found in the arid regions of Western Australia,
Queensland, and the Northern Territory. They are most extensive in the
latter area. These soils are grazed sparingly because of the poor coverage
of vegetation of spinifex and grasses.
Certain tablelands in Australia also may be extensively covered with
stones which represent a former, more humid era. Their desert pavement
surface is composed of broken and polished siliceous stones (Jessup,
1962). Brown-to-red loam to clay-loam textured A horizon lies below the
pavement. In the Bl, coarse-textured clay overlays a gypsiferous clay with
some lime accumulated in the lighter colored B2. The stony desert tableland soils are found on the Gibson Desert in Western Australia, in South
Australia, and the Stuart Desert extending into Queensland. They are
poorly covered with sparse shrub-type steppe vegetation of low cattle and
sheep carrying capacity (Jessup, 1951 ).
Gray-brown and red-calcareous desert soils occur extensively in the Nullarbor Plain of South and West Australia and to a certain extent in other
arid regions (Jackson, 1957). Shrubs and grasses inhabit these soils
sparsely but are little used.
Desert loams are fine-textured soils containing some lime and gypsum
and frequently show signs of salt effects. They appear in the 12- to 25-cm
rainfall areas of southern Australia and may be covered with thin layers
of sand or stones. They are sparingly grazed. Vegetation consists of
ephemeral natural herbage and perennial edible shrubs which resemble the
shrub-type steppe vegetation.
Limy soils are concentrated more on the desert fringes than in the heart
of the arid lands, whereas gypsiferous soils appear on the more arid lands.
Solonchak (salty soils) and Solonetz (sodium-affected soils) are scattered
in depressions and in soils with saline subsoils in all areas of Australia
(Downes, 1954). Because of the extensive nature of the salt-affected land
in Australia, Stephens (1961 ) suggests that the soil salinity is derived from
wind-blown ocean spray. The parent materials on which salty soils occur
cannot account for the salt accumulations observed.
A wide variety of desert soils are found in Australia. Sandy and stony
soils are extensive and clay and loams are interspersed throughout the arid
region as are salt-affected soils. Vegetation is sparse mostly because of