Kandiudult
Soil profile: A representative soil profile of a Plinthic Kandiudult in Webster County, Georgia.
Plinthic Kandiudults that have 5 percent or more (by volume) plinthite in one or more horizons within 150 cm of the mineral soil surface.
Kandiudults are the Udults that are very deep and have a kandic horizon and a clay distribution in which the percentage of clay does not decrease from its maximum amount by as much as 20 percent within a depth of 150 cm from the mineral soil surface, or the layer in which the clay percentage decreases has at least 5 percent of the volume consisting of skeletans on faces of peds and there is at least a 3 percent (absolute) increase in clay content below this layer. These soils do not have a fragipan or a horizon in which plinthite either forms a continuous phase or constitutes one-half or more of the volume within 150 cm of the mineral soil surface. Kandiudults are of moderate extent in the Southeastern United States.
Ultisols are soils that have an argillic or kandic horizon with low base saturation. They may have any soil temperature regime and any soil moisture regime except aridic. There is more precipitation than evapotranspiration at some season, and some water moves through the soils and into a moist or wet substratum. The release of bases by weathering usually is equal to or less than the removal by leaching, and most of the bases commonly are held in the vegetation and the upper few centimeters of the soils. Base saturation in most Ultisols decreases with increasing depth because the vegetation has concentrated the bases at a shallow depth.
Cultivation, therefore, is a shifting cultivation unless soil amendments are applied. Ultisols are most extensive in warm, humid climates that have a seasonal deficit of precipitation. They are mainly on Pleistocene or older surfaces. They formed in a very wide variety of parent materials, but very few have many primary minerals that contain bases other than some micas. Some of the few that have a supply of bases are intensively cultivated. Kaolin, gibbsite, and aluminum-interlayered clays are common in the clay fraction. Smectites also may be present if they are in the parent materials. Extractable aluminum normally is high. A calcium deficient argillic horizon is common in the Ultisols in the United States. Most of the Ultisols in the United States had a vegetation of coniferous or hardwood forests at the time of settlement.
For additional information about soil classification, visit:
www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/survey/cla...
Kandiudult
Soil profile: A representative soil profile of a Plinthic Kandiudult in Webster County, Georgia.
Plinthic Kandiudults that have 5 percent or more (by volume) plinthite in one or more horizons within 150 cm of the mineral soil surface.
Kandiudults are the Udults that are very deep and have a kandic horizon and a clay distribution in which the percentage of clay does not decrease from its maximum amount by as much as 20 percent within a depth of 150 cm from the mineral soil surface, or the layer in which the clay percentage decreases has at least 5 percent of the volume consisting of skeletans on faces of peds and there is at least a 3 percent (absolute) increase in clay content below this layer. These soils do not have a fragipan or a horizon in which plinthite either forms a continuous phase or constitutes one-half or more of the volume within 150 cm of the mineral soil surface. Kandiudults are of moderate extent in the Southeastern United States.
Ultisols are soils that have an argillic or kandic horizon with low base saturation. They may have any soil temperature regime and any soil moisture regime except aridic. There is more precipitation than evapotranspiration at some season, and some water moves through the soils and into a moist or wet substratum. The release of bases by weathering usually is equal to or less than the removal by leaching, and most of the bases commonly are held in the vegetation and the upper few centimeters of the soils. Base saturation in most Ultisols decreases with increasing depth because the vegetation has concentrated the bases at a shallow depth.
Cultivation, therefore, is a shifting cultivation unless soil amendments are applied. Ultisols are most extensive in warm, humid climates that have a seasonal deficit of precipitation. They are mainly on Pleistocene or older surfaces. They formed in a very wide variety of parent materials, but very few have many primary minerals that contain bases other than some micas. Some of the few that have a supply of bases are intensively cultivated. Kaolin, gibbsite, and aluminum-interlayered clays are common in the clay fraction. Smectites also may be present if they are in the parent materials. Extractable aluminum normally is high. A calcium deficient argillic horizon is common in the Ultisols in the United States. Most of the Ultisols in the United States had a vegetation of coniferous or hardwood forests at the time of settlement.
For additional information about soil classification, visit:
www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/survey/cla...