Udic Paleustoll ZM
A representative soil profile of a fine, mixed, semiactive isohyperthermic Udic Paleustoll. (Photo and comments courtesy of Stan Buol, NCSU.)
This profile was photographed in Zambia, Africa. The soil is formed in limestone derived sediment on a nearly level slope. The site has been used as cropland for many years and there is no record of natural vegetation.
The surface Ap horizon (0-18 cm) is clay loam in texture below which clay content increases to between 50 and 60 percent to a depth of 180 cm. Organic carbon content exceeds 1 percent from the surface to a depth of 70 cm. Base saturation percentage (CEC7) exceeds 60 percent throughout the entire profile.
The main crops grown are maize, sorghum, soybeans, beans, cotton and sunflowers. The clay loam Ap horizon presents some difficulty for hand hoe cultivation but mechanized cultivation prepares better seed bed tilth.
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Udic Paleustolls are more moist than Typic Paleustolls and generally have carbonates at a greater depth. Slopes of the Udic Paleustolls in the United States are mostly gentle. The soils are of moderate extent, mostly on the southern Great Plains of the United States. Most of the soils supported grasses and shrubs and are used as cropland.
Paleustolls are the Ustolls on old stable surfaces. They may commonly have a thick, reddish argillic horizon, or, more commonly, a clayey argillic horizon that has an abrupt upper boundary, or they may have a petrocalcic horizon. They commonly have been partly or completely calcified during the Holocene, and a Bk or calcic horizon is common in the argillic horizon. The Paleustolls in the United States are mainly in the central and southern parts of the Great Plains. At the time of settlement, they had mostly grass vegetation. Their history during the Pleistocene has had little study. The petrocalcic horizon, where it occurs, may be complex, suggesting a number of alternating cycles of humidity and aridity and slow accretion of dust and sediment from the arid regions to the west.
Ustolls are the more or less freely drained Mollisols of subhumid to semiarid climates. Rainfall occurs mainly during a growing season, often in heavy showers, but is erratic. Drought is frequent and may be severe. During a drought, soil blowing becomes a problem. Without irrigation, the low supply of moisture usually limits crop yields. Ustolls are extensive soils on the western Great Plains in the United States.
For more information about describing soils, visit:
www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs142p2_052523...
For additional information about soil classification using Soil Taxonomy, visit:
Udic Paleustoll ZM
A representative soil profile of a fine, mixed, semiactive isohyperthermic Udic Paleustoll. (Photo and comments courtesy of Stan Buol, NCSU.)
This profile was photographed in Zambia, Africa. The soil is formed in limestone derived sediment on a nearly level slope. The site has been used as cropland for many years and there is no record of natural vegetation.
The surface Ap horizon (0-18 cm) is clay loam in texture below which clay content increases to between 50 and 60 percent to a depth of 180 cm. Organic carbon content exceeds 1 percent from the surface to a depth of 70 cm. Base saturation percentage (CEC7) exceeds 60 percent throughout the entire profile.
The main crops grown are maize, sorghum, soybeans, beans, cotton and sunflowers. The clay loam Ap horizon presents some difficulty for hand hoe cultivation but mechanized cultivation prepares better seed bed tilth.
____________________________________
Udic Paleustolls are more moist than Typic Paleustolls and generally have carbonates at a greater depth. Slopes of the Udic Paleustolls in the United States are mostly gentle. The soils are of moderate extent, mostly on the southern Great Plains of the United States. Most of the soils supported grasses and shrubs and are used as cropland.
Paleustolls are the Ustolls on old stable surfaces. They may commonly have a thick, reddish argillic horizon, or, more commonly, a clayey argillic horizon that has an abrupt upper boundary, or they may have a petrocalcic horizon. They commonly have been partly or completely calcified during the Holocene, and a Bk or calcic horizon is common in the argillic horizon. The Paleustolls in the United States are mainly in the central and southern parts of the Great Plains. At the time of settlement, they had mostly grass vegetation. Their history during the Pleistocene has had little study. The petrocalcic horizon, where it occurs, may be complex, suggesting a number of alternating cycles of humidity and aridity and slow accretion of dust and sediment from the arid regions to the west.
Ustolls are the more or less freely drained Mollisols of subhumid to semiarid climates. Rainfall occurs mainly during a growing season, often in heavy showers, but is erratic. Drought is frequent and may be severe. During a drought, soil blowing becomes a problem. Without irrigation, the low supply of moisture usually limits crop yields. Ustolls are extensive soils on the western Great Plains in the United States.
For more information about describing soils, visit:
www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs142p2_052523...
For additional information about soil classification using Soil Taxonomy, visit: