LOCATION NEDERLAND COEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic Aridic Argiustolls
TYPICAL PEDON: Nederland cobbly sandy loam - grassland. (Colors are for dry soil unless otherwise noted.)
A--0 to 4 inches; brown (7.5YR 5/2) cobbly sandy loam, dark brown (7.5YR 3/2) moist; moderate fine granular structure; soft, very friable; 15 percent cobble and 15 percent pebbles; common medium and coarse angular granite sand; neutral (pH 6.6); clear smooth boundary. (3 to 6 inches thick)
BA--4 to 7 inches; brown (7.5YR 5/3) very cobbly heavy coarse sandy loam, dark brown (7.5YR 3/3) moist; weak medium subangular blocky structure parting to moderate fine granular; hard, friable, nonplastic; few thin glossy patches on the faces of peds and glossy coatings on pebbles and cobbles; 25 percent cobble and 25 percent pebbles; common medium coarse angular granite sand; neutral (pH 6.6); clear smooth boundary. (2 to 4 inches thick)
Bt--7 to 15 inches; reddish brown (5YR 5/3) very cobbly coarse sandy clay loam, dark reddish brown (5YR 3/3) moist; weak medium prismatic structure parting to moderate medium subangular blocky; extremely hard, friable, sticky, plastic; many thin wax-like patches on faces of peds; wax-like coatings on sand and gravel fragments, and wax-like bridges between sand grains; 25 percent cobble and 25 percent pebbles; common medium and coarse angular granite sand; neutral (pH 6.6); gradual wavy boundary. (6 to 14 inches thick)
BCt--15 to 20 inches; reddish brown (2.5YR 5/4) very cobbly light coarse sandy clay loam, reddish brown (2.5YR 4/4) moist; weak medium subangular blocky structure; extremely hard, very friable, sticky, plastic; few thin glossy patches on the vertical faces of peds, some glossy coatings on sand grains and bridges between sand grains; 25 percent cobble and 30 percent pebbles; common medium and coarse angular granite sand; neutral (pH 6.6); gradual wavy boundary. (4 to 6 inches thick)
C--20 to 60 inches; reddish brown (2.5YR 5/4) very cobbly coarse sandy loam, reddish brown (2.5YR 4/4) moist; massive; extremely hard, very friable, slightly sticky, nonplastic; 30 percent cobble and 30 percent pebbles; common medium and coarse angular granite sand; neutral (pH 6.6).
TYPE LOCATION: Boulder County, Colorado; approximately 950 feet south of the center of Sec. 28, T. 1 S., R. 70 W.
RANGE IN CHARACTERISTICS: The mollic epipedon ranges from 7 to 19 inches thick. The solum ranges from 15 to 30 inches thick. Exchangeable sodium percentage is typically less than 3 and does not exceed 14 in any horizon as much as 4 inches thick within the solum. The argillic horizon averages 18 to 35 percent clay. A large portion of the sand fraction is medium and coarse angular granite sand. Packing patterns within the matrix tend to be cubical with a high proportion of flat bearing surfaces between sand grains. Horizons of low organic matter content have a greater than normal differential in consistence between moist and dry conditions and the soils are said to be "hard setting" when dry. Rock fragments range from 35 to 75 percent in the solum and C horizons and are mostly fine and very fine angular granite gravel. Mean annual soil temperature ranges from 47 to 58 degrees F, and mean summer soil temperature ranges from 59 to 79 degrees F. The time soil temperature at a depth of 20 inches is 41 degrees F or higher ranges approximately from 230 to 305 days. Cumulative time the soil is moist in some part of the moisture control section and the soil temperature at 20 inches is 41 degrees F or higher ranges from approximately 56 to 152 days.
The A horizon has hue of 7.5YR or 5YR, value of 4 or 5, 2 or 3 moist, and chroma of 2 or 3. It usually has granular primary structure but has subangular blocky structure in some pedons. This horizon is soft to slightly hard. It is slightly acid to mildly alkaline.
The Bt horizon has hue of 5YR through 10R, value of 5 through 7, 3 through 6 moist, and chroma of 2 through 5. It is typically sandy clay loam but clay ranges from 18 to 35 percent, silt from 5 to 30 percent, and sand from 45 to 75 percent with more than 35 percent fine sand or coarser, and with a high proportion of medium and coarse angular granite sand. It is slightly acid to moderately alkaline.
The C horizon has hue of 5YR through 10R. Subhorizons having hue of 7.5YR occur in the solum and C horizons in some pedons but are inconsistent from pedon to pedon or are associated with hue of 5YR or redder in other subhorizons of the same pedon. This horizon is slightly acid to mildly alkaline and there is little or no increase in pH within 40 inches.
COMPETING SERIES: These are the Irock, (T)Lantis, Majada, Mokiak, Montoso, Murdo, Purcella, Salas, and Willowman series. Mokiak and Salas soils have a lithic contact at depths of less than 40 inches. (T)Lantis and Purcella soils have continuous horizons of secondary carbonate accumulation. Irock and Majada soils are calcareous above a depth of 40 inches and have continuous horizons of secondary carbonate accummulation. Montoso overly beds of cinders above a depth of 40 inches and are influenced by ash and pyroclastic material. Willowman soils have a calcic horizon. Murdo soils have hues of 7.5YR and yellower in the Bt and C horizons.
GEOGRAPHIC SETTING: The Nederland soils are on high terraces or alluvial fans. Slope gradients range from 0 to about 6 percent. The soils formed in very cobbly and gravelly alluvial fan or terrace alluvium derived principally from granite. At the type location the average annual precipitation is 13 to 18 inches with peak periods of precipitation in the spring and summer months. Mean annual temperature is 48 degrees F, and mean summer temperature is 68 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Peyton and Valmont soils. Peyton soils contain less than 35 percent gravel and have a mean annual soil temperature colder than 47 degrees F. Valmont soils have a fine textured argillic horizon.
DRAINAGE AND PERMEABILITY: Well drained; medium to slow runoff; moderate permeability.
USE AND VEGETATION: Usually used as native pastureland. Around major cities they are used for urban housing and other development projects. Principal native vegetation is blue grama, needleandthread grass, and western wheatgrass.
DISTRIBUTION AND EXTENT: Central portions of Colorado bordering the front range. The series has moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Boulder Area, Colorado, 1971.
REMARKS:
The superactive cation exchange activity class was added in 03/2003 to the taxonomic classification by the National Soil Survey Center on request of the Reno MLRA office, without review of the soil series property data. The remainder of this document has not been updated.