LOCATION TRAG CO+NM UTEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Typic Argiustolls
TYPICAL PEDON: Trag sandy loam, rangeland. (Colors are for dry soil unless otherwise noted.)
A--0 to 9 inches; dark grayish brown (10YR 4/2) sandy loam, very dark brown (10YR 2/2) moist; weak medium subangular blocks parting to moderate fine granular structure; soft, very friable; slightly acid; clear wavy boundary. (4 to 15 inches thick)
BA--9 to 15 inches; brown (10YR 5/3) clay loam, dark brown (10YR 3/3) moist; weak medium prisms parting to moderate medium subangular blocky structure; hard, firm; thin patchy clay films; neutral; clear wavy boundary. (0 to 12 inches thick)
Bt--15 to 35 inches; brown (7.5YR 5/4) clay loam, dark brown (7.5YR 4/4) moist; moderate medium prisms parting to moderate medium subangular blocky structure; very hard, firm; thin nearly continuous clay films; neutral; clear smooth boundary. (16 to 34 inches thick)
C--35 to 60 inches; brown (7.5YR 5/4) sandy clay loam, dark brown (7.5YR 4/4) moist; weak medium subangular blocky structure; very hard, friable; neutral.
TYPE LOCATION: Larimer County, Colorado; 2,350 feet east and 600 feet south of the NW corner of Sec. 10, T. 7 N., R. 71 W.
RANGE IN CHARACTERISTICS:
Soil moisture: Ustic moisture regime.
Peak precipitation coming during the months of March through June.
Mean annual soil temperature: 45 to 47 degrees F
Mean summer soil temperature: 59 to 60 degrees F
Depth to secondary calcium carbonate: 40 or more inches
Particle-size control section (weighted average):
Clay content: 18 to 35 percent
Sand content: 30 to 65 percent
Rock fragments: 0 to 30 percent by volume
A horizon:
Hues: 7.5YR or 10YR
Value: 3 through 5 dry, 2 or 3 moist
Chroma: 2 or 3
Base saturation: 75 to 100 percent
Reaction: slightly acid to mildly akaline
BA horizon (if present):
Hues: 7.5YR or 10YR
Value: 3 through 6 dry, 2 through 6 moist
Chroma: 2 through 4
Texture: clay loam, sandy clay loam, sandy loam, loam
Reaction: slightly acid to mildly alkaline
Bt horizon(s):
Hues: 7.5YR or 10YR
Value: 4 through 6 dry, 3 through 5 moist
Chroma: 2 through 6
Texture: clay loam, sandy clay loam, loam, silty clay loam
Clay content: 18 to 35 percent
Reaction: neutral to mildly alkaline
Bridging of clay between sand grains and clay films exist on vertical ped faces and in pores.
C horizon (if present):
Hues: 7.5YR or 10YR
Texture: clay loam, sandy clay loam, loam
Base saturation: 90 to 100 percent
Reaction: neutral to moderately alkaline
COMPETING SERIES:
Absarook - calcium carbonate above 40 inches depth
Archmesa - moderately deep to bedrock
Bielenberg - deep to bedrock
Burtoner - moderately deep to bedrock
Clancy - moderately deep to bedrock
Clasoil - have hues as yellow as 2.5Y
Dooley - calcium carbonate above 40 inches depth
Doughty - calcium carbonate above 40 inches depth
Empedrado - calcium carbonate above 40 inches depth
Fairfield - calcium carbonate above 40 inches depth
Farnuf - calcium carbonate above 40 inches depth
Farside - lower elevations and more northernly latitudes
Felor - calcium carbonate above 40 inches depth
Greenway - calcium carbonate above 40 inches depth
Gurney - moderately deep to bedrock
Hangdo - formed in eolian material over alluvium
Hoppers - moderately deep to bedrock
Hyalite - lithologic discontinuity in Bt
Jeffcity - moderately deep to bedrock
Kokoruda - forested soil with O horizon
Livona - calcium carbonate above 40 inches depth
Martinsdale - calcium carbonate above 40 inches depth
Maudlin - moderately deep to bedrock
Meagher - calcium carbonate above 40 inches depth
Moen - moderately deep to bedrock
Moento - moderately deep to bedrock
Pianohill - moderately deep to bedrock
Placerton - moderately deep to bedrock
Reeder - moderately deep to bedrock
Reedwest - modrately deep to bedrock
Snakejohn - deep to bedrock
Tragmon - formed sandstone and shale parent material
Trazuni - redox features in the lower part
Ulrant - deep to bedrock
Vida - calcium carbonate above 40 inches depth
Watne - calcium carbonate above 40 inches depth
Watrous - moderately deep to bedrock
Williams - calcium carbonate above 40 inches depth
Yegen - calcium carbonate above 40 inches depth
GEOGRAPHIC SETTING: Trag soils are on mountain slopes and fans. Slopes range from 1 to 40 percent. The soil formed in material weathered from granite and schist that has been locally transported in places. Elevation ranges from 6,800 to 8,900 feet. The soils are in a cool semiarid climate with annual precipitation ranging from 15 to 22 inches. The mean annual temperature is 43 to 46 degrees F. The frost- free season is about 65 to 100 days. In New Mexico, precipitation ranges to 22 inches with air temperatures down to 40 degrees F. and frost-free periods up to 110 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Boyle, Bruce, Ratake, and Wetmore soils and the competing Farnuf and Moen soils. Boyle, Ratake and Wetmore soils have bedrock at depths of less than 20 inches. Bruce soils are coarse-loamy.
DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff; moderate to moderately slow permeability.
USE AND VEGETATION: The soils are used for rangeland. Native vegetation is mainly blue grama, big and little bluestem, junegrass, some forbs and shrubs, and widely spaced ponderosa pine.
DISTRIBUTION AND EXTENT: Mountainous parts of Northern and central Colorado, eastern Utah, and central New Mexico. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Larimer County, Colorado, 1975. The name is a coined name.
REMARKS: This soil has:
Mollic Epipedon: The zone from 0 to 15 inches
Argillic Horizon: The zone from 15 to 35 inches
Prior to 2/1999 OSD update the classification was a Typic Argiboroll, fine-loamy, mixed. The 2/1999 update reclassified this series to a Pachic Argiustoll, fine-loamy, mixed, superactive, frigid. Historically this series concept was not pachic. Therefore, in this update a one inch reduction in the thickness of the mollic epipedon was incorporated and adjustment to the range in characteristics to maintain the series concept as typic.
Taxanomic Version: Eighth Edition, 1998