LOCATION TRUJILLO COEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Typic Argiustolls
TYPICAL PEDON: Trujillo loam, on a south facing, moderately sloping, 7 percent slope in grass at an elevation of 7,050 feet. (Colors are for dry soil unless otherwise noted.) When described on June 13, 1984 the soil was moist from 13 to 33 inches.
A--0 to 9 inches; dark grayish brown (10YR 4/2) loam, very dark grayish brown (10YR 3/2) moist; moderate medium granular structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine roots; neutral (pH 6.6); clear smooth boundary. (7 to 10 inches thick)
Bt1--9 to 13 inches; dark grayish brown (10YR 4/2) loam, dark brown (10YR 3/3) moist; moderate medium prismatic structure parting to moderate medium subangular blocks; hard, friable, slightly sticky and slightly plastic; common very fine and fine roots; common patchy distinct clay films on faces of peds; neutral (pH 6.8); clear smooth boundary.
Bt2--13 to 26 inches; dark grayish brown (10YR 4/2) clay loam, brown (10YR 4/3) moist and crushed; moderate medium prismatic structure parting to moderate medium subangular blocks; very hard, firm, slightly sticky and slightly plastic; common continuous clay films on faces of peds; neutral (pH 6.8); clear smooth boundary.
Bt3--26 to 36 inches; brown (10YR 5/3) sandy clay loam, brown (10YR 4/3) moist; moderate fine and medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; few patchy distinct clay films on faces of peds; neutral (pH 7.3); clear smooth boundary. (Combined thickness of the Bt horizons is 23 to 40 inches)
Bw--36 to 58 inches; yellowish brown (10YR 5/4) fine sandy loam, dark yellowish brown (10YR 4/4) moist; weak coarse subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few fine and very fine roots; few patchy distinct pressure faces on cracks; slightly alkaline (pH 7.4); clear smooth boundary. (0 to 15 inches thick)
Bk--58 to 70 inches; yellowish brown (10YR 5/4) fine sandy loam, dark yellowish brown (10YR 4/4) moist; massive; slightly hard, friable, nonsticky and nonplastic; few fine and very fine roots; few fine irregular soft masses of lime; slightly effervescent (matrix is noneffervescent); slightly alkaline (pH 7.5).
TYPE LOCATION: Las Animas County, Colorado; about 0.6 miles north of Gulnare, Colorado; located about 1,150 feet east and 800 feet north of the southwest corner of sec. 23, T. 31 S., R. 66 W.; Gulnare USGS quad; lat. 37 degrees 19 minutes 32 seconds N. and long. 104 degrees 45 minutes 17 seconds W., NAD 1923
RANGE IN CHARACTERISTICS:
Soil moisture: The soil moisture control section is moist in some part April through August; ustic moisture regime.
Mean annual soil temperature: 40 to 46 degrees F
Mean summer soil temperature: 60 to 63 degrees F
Depth to argillic horizon: 7 to 10 inches
Depth to secondary calcium carbonate: 40 to 65 inches
Thickness of the argillic: 23 to 40 inches
Particle-size control section (weighted average):
Clay content: 20 to 30 percent
Sand content: 40 to 60 percent
Rock fragments: 0 to 5 percent gravel
A horizon:
Hue: 7.YR or 10YR
Value: 3 or 4 dry, 2 or 3 moist
Chroma: 2 or 3
Texture: loam, sandy loam
Clay content: 10 to 20 percent
Rock fragments: 0 to 5 percent
Reaction: slightly acid or neutral
A BA horizon is present in some pedons
Bt horizons:
Hue: 7.5YR or 10YR
Value: 4 to 6 dry, 3 to 5 moist
Chroma: 2 to 4
Texture: sandy clay loam, clay loam
Clay content: 20 to 35 percent
Rock fragments: 0 to 5 percent
Base saturation: 85 to 100 percent
Reaction: slightly acid to slightly alkaline
Bw horizon: (if present)
Hue: 7.5YR or 10YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 3 or 4
Texture: fine sandy loam, sandy loam, loam, sandy clay loam
Clay content: 15 to 27 percent
Rock fragments: 0 to 15 percent
Reaction: neutral or slightly alkaline
Bk horizon:
Hue: 7.5YR or 10YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 3 to 6
Texture: fine sandy loam, sandy loam, loam, sandy clay loam
Clay content: 15 to 27 percent
Rock fragments: 0 to 15 percent
Calcium carbonate equivalent: 1 to 3 percent
Reaction: neutral or slightly alkaline
COMPETING SERIES: These are the
Absarook,
Archmesa,
Beartooth,
Beeno (WY),
Bielenberg,
Bookcliff,
Burtoner,
Clancy,
Clasoil,
Dooley,
Doughty,
Empedrado,
Fairfield,
Farnuf,
Farside,
Felor,
Greenway,
Gurney,
Hangdo,
High (CO),
Hoppers,
Hyalite,
Jeffcity,
Kokoruda,
Livona,
Martinsdale,
Maudlin,
Meagher,
Moen,
Moento,
Pianohill,
Placerton,
Reeder,
Reedwest,
Sipple (MT),
Snakejohn,
Sponseller,
Trag,
Tragmon,
Trazuni,
Ulrant,
Vida,
Watne,
Watrous,
Williams, and
Yegen series.
Absarook soils: have calcium carbonate above a depth of 40 inches
Archmesa soils: are moderately deep to bedrock
Beartooth soils: have calcium carbonate above a depth of 40 inches
Beeno soils: have a lithic contact at depths of 20 to 40 inches.
Bielenberg soils: are deep to bedrock
Bookcliff soils: have calcium carbonate above a depth of 40 inches
Burtoner soils: are moderately deep to bedrock
Clancy soils: are moderately deep to bedrock
Clasoil soils: have 15 to 45 percent rock fragments in the BC horizon
Dooley soils: have calcium carbonate above a depth of 40 inches
Doughty soils: have calcium carbonate above a depth of 40 inches
Empedrado soils: have calcium carbonate above a depth of 40 inches
Fairfield soils: have calcium carbonate above a depth of 40 inches
Farnuf soils: have calcium carbonate above a depth of 40 inches
Farside soils: have a mean annual temperature of 37 to 41 degrees F.
Felor soils: have calcium carbonate above a depth of 40 inches
Greenway soils: have calcium carbonate above a depth of 40 inches
Gurney soils: are moderately deep to bedrock
Hangdo soils: have greater than 15 percent rock fragments in the lower Bt horizons and BC horizon
High soils: have calcium carbonate above a depth of 40 inches
Hoppers soils: are moderately deep to bedrock
Hyalite soils: have a lithologic discontinuity in the Bt
Jeffcity soils: are moderately deep to bedrock
Kokoruda soils: are forested with an O horizon
Livona soils: have calcium carbonate above a depth of 40 inches
Martinsdale soils: have calcium carbonate above a depth of 40 inches
Maudlin soils: are moderately deep to bedrock
Meagher soils: have calcium carbonate above a depth of 40 inches
Moen soils: are moderately deep to bedrock
Moento soils: are moderately deep to bedrock
Pianohill soils: are moderately deep to bedrock
Placerton soils: are moderately deep to bedrock
Reeder soils: are moderately deep to bedrock
Reedwest soils: are moderately deep to bedrock
Sipple soils: have calcium carbonate above a depth of 40 inches
Snakejohn soils: are deep to bedrock
Sponseller soils: have hues redder than 7.5YR
Trag soils: have peak moisture March through June and formed from granite and schist
Tragmon soils: have continuous moisture throughout the year
Trazuni soils: have redox features in the lower part of the profile
Ulrant soils: are deep to bedrock
Vida soils: have calcium carbonate above a depth of 40 inches
Watne soils: have calcium carbonate above a depth of 40 inches
Watrous soils: are moderately deep to bedrock
Williams soils: have calcium carbonate above a depth of 40 inches
Yegen soils: have calcium carbonate above a depth of 40 inches
GEOGRAPHIC SETTING:
Parent material: alluvium derived from coarse sandstone
Landform: hills, drainageways and fans
Slopes: 3 to 25 percent
Elevation: 6,800 to 8,000 feet
Mean annual temperature: 43 to 46 degrees F
Mean annual precipitation: 17 to 22 inches
Precipitation pattern: moist spring and summer, dry winters
Wettest period: April through August
Driest period: November through February
Frost-free period: 70 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Breece, Gulnare, Littlepine, and Molinaro series. The Breece soils are coarse-loamy and are on fans. The Gulnare soils are shallow to lithic contact and are on forested hills. The Littlepine soils lack a mollic epipedon and are on forested fans and hills. The Molinaro soils lack argillic horizons and are on fans and terraces.
DRAINAGE AND PERMEABILITY: Well drained, low to medium runoff, moderate permeability.
USE AND VEGETATION: Rangeland, hayland and wildlife habitat. The native vegetation is mainly western wheatgrass, green needlegrass, blue grama, little bluestem, sideoats grama, mountain muhly, pine dropseed, and fringed sagebrush. Some areas have scattered ponderosa pine.
DISTRIBUTION AND EXTENT: foothills of southeastern Colorado; LRR E, MLRA 49; moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Las Animas County, Colorado, 2007, Las Animas and parts of Huerfano county soil survey area, Colorado. The name was taken from a major drainage in the area.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Particle-size control section: The zone from 9 to 29 inches. (Bt1, Bt2 and part of the Bt3 horizons)
Mollic epipedon: The zone from 0 to 13 inches. (A and Bt1 horizons; the organic carbon criterion is not met in the Bt2 horizon.)
Argillic horizon: The zone from 9 to 36 inches. (Bt1, Bt2, and Bt3 horizons)
Cambic horizon: The zone from 36 to 58 inches. (Bw horizon (not always present))
Other features:
Secondary calcium carbonate: the zone from 58 to 70 inches. (Bk horizon)
The assignment of the cation-exchange activity class is supported by lab sample(s) number S87CO-071-009.
Taxonomic Version: Tenth Edition, 2006
ADDITIONAL DATA: Laboratory sample #S87CO-071-009