1. Do not have a densic, lithic, paralithic, or petroferric contact within 150 cm of the mineral soil surface; and 2. Have a kandic horizon; and 3. Within 150 cm of the mineral soil surface, either: a. With increasing depth, do not have a clay decrease of 20 percent or more (relative) from the maximum clay content; or b. Have 5
percent or more (by volume) clay depletions on faces of peds in the layer that
has a 20 percent lower clay content and, below that layer,
a clay increase of 3 percent or more (absolute) in the
fine-earth fraction.
Kandihumults are the Humults that: 1. Have a kandic horizon; 2. Do not have a densic, lithic, paralithic, or petroferric contact within 150 cm of the mineral soil surface; 3. Have 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 by more than 20 percent has at least 5 percent of the volume consisting of clay depletions on faces of peds and there is at least a 3 percent (absolute) increase in clay content below this layer; 4. Do not have a sombric horizon within 150 cm of the mineral soil surface; and 5. Do not have plinthite that forms a continuous phase or that constitutes more than 50 percent of the volume of some subhorizon within 150 cm of the mineral soil surface.
1. Throughout one or more horizons with a total thickness of 18 cm or more within 75 cm of the mineral soil surface, have a fine-earth fraction with both a bulk density of 1.0 g/cm3 or less, measured at 33 kPa water retention, and Al plus 1/2 Fe percentages (by ammonium oxalate) totaling more than 1.0; and 2. In one or more horizons within 75 cm of the mineral soil surface, have redox concentrations, a color value, moist, of 4 or more, and hue that is 10YR or yellower and becomes redder with increasing depth within 100 cm of the mineral soil surface; and 3. In normal years are saturated with water in one or more layers within 100 cm of the mineral soil surface for either or both: a. 20 or more consecutive days; or b. 30 or more
cumulative days.
1. Throughout one or more horizons with a total thickness of 18 cm or more within 75 cm of the mineral soil surface, a fine-earth fraction with both a bulk density of 1.0 g/cm3 or less, measured at 33 kPa water retention, and Al plus 1/2 Fe percentages (by ammonium oxalate) totaling more than 1.0; and 2. An ustic
moisture regime.
1. Have, in one or more horizons within 75 cm of the mineral soil surface, redox concentrations, a color value, moist, of 4 or more, and hue that is 10YR or yellower and becomes redder with increasing depth within 100 cm of the mineral soil surface; and 2. In normal years are saturated with water in one or more layers within 100 cm of the mineral soil surface for either or both: a. 20 or more consecutive days; or b. 30 or more
cumulative days.
Typic Kandihumults are the Kandihumults that: 1. Do not have, in any subhorizon within the upper 25 cm of the kandic horizon, redox depletions with a color value, moist, of 4 or more and chroma of 2 or less, accompanied by redox concentrations and by aquic conditions; 2. Have a udic moisture regime; 3. Do not have, throughout a cumulative thickness of 18 cm or more and within a depth of 75 cm, a bulk density, in the fraction less than 2.0 mm in size, of 1.0 g/cm3 or less, measured at 33 kPa water retention, and acid-oxalate-extractable aluminum plus 1/2 acid-oxalate-extractable iron of more than 1.0 percent; 4. Have less than 5 percent (by volume) plinthite in all subhorizons within 150 cm of the mineral soil surface; 5. Do not have, in one or more horizons within 75 cm of the mineral soil surface, redox concentrations, a color value, moist, of 4 or more, and hue that is 10YR or yellower and becomes redder with increasing depth within 100 cm of the mineral soil surface; and 6. Do not have an anthropic epipedon. pages by sootin claimon : sootinc@gmail.com |