LOCATION UZACOL             CO
Established Series
Rev. DKR/JWH/WWJ
09/2007

UZACOL SERIES


The Uzacol series consists of deep, well drained soils that formed in slope alluvium over residuum derived from shale. Uzacol soils are on toeslopes and footslopes of hills. Slopes range from 3 to 9 percent. Mean annual precipitation is about 9 inches and the mean annual temperature is about 54 degrees F.

TAXONOMIC CLASS: Fine, smectitic, mesic Vertic Natrargids

TYPICAL PEDON: Uzacol clay loam, on a 7 percent slope in native vegetation at an elevation of 5,500 feet. (Colors are for dry soil unless otherwise noted.) The surface is covered by 1 percent stones and 5 percent gravel.

A1--0 to 1 inches; light brown (7.5YR 6/4) clay loam with about 1 percent stones on the surface, reddish brown (5YR 5/3) moist; moderate medium granular structure; slightly hard, friable, moderately sticky and moderately plastic; 5 percent gravel and 1 percent stones; strongly effervescent; moderately alkaline (pH 8.4); clear smooth boundary. (1 to 3 inches thick)

A2--1 to 5 inches; light brown (7.5YR 6/4) clay loam, reddish brown (5YR 5/3) moist; weak thick platy structure parting to moderate medium granular; slightly hard, firm, moderately sticky and moderately plastic; strongly effervescent; moderately alkaline (pH 8.4); clear smooth boundary. (0 to 4 inches thick)

Btn1--5 to 16 inches; light brown (7.5YR 6/4) clay, reddish brown (5YR 5/4) moist; moderate coarse prismatic structure parting to moderate medium subangular blocky and angular blocky; very hard, very firm, very sticky and moderately plastic; common faint clay films on the faces of peds and in pores; strongly effervescent; strongly alkaline (pH 9.0); gradual smooth boundary. (6 to 14 inches thick)

Btn2--16 to 26 inches; light brown (7.5YR 6/4) clay, reddish brown (5YR 5/4) moist; moderate medium subangular blocky structure; hard, very firm, very sticky and moderately plastic; common faint clay films on the faces of peds and in pores; strongly effervescent; strongly alkaline (pH 8.8); gradual smooth boundary. (6 to 14 inches thick)

Btn3--26 to 31 inches; light brown (7.5YR 6/4) clay, reddish brown (5YR 5/4) moist; weak to moderate medium subangular blocky structure; hard, firm, moderately sticky and moderately plastic; common faint clay films on the faces of peds and in pores; strongly effervescent; strongly alkaline (pH 8.8); gradual smooth boundary. (0 to 6 inches thick)

Bkn--31 to 45 inches; light reddish brown (5YR 6/4) clay, light reddish brown (5YR 6/3) moist; weak to moderate medium subangular blocky structure; hard, firm, moderately sticky and moderately plastic; 10 percent gravel; few fine soft masses of calcium carbonate; violently effervescent; strongly alkaline (pH 8.8); gradual wavy boundary. (6 to 20 inches thick)

Bky--45 to 59 inches; pink (5YR 7/4) clay, brown (7.5YR 5/4) moist; weak medium subangular blocky structure parting to weak fine subangular blocky; hard, firm, moderately sticky and moderately plastic; 10 percent gravel, many fine soft masses of gypsum and calcium carbonate; violently effervescent; moderately alkaline (pH 8.2). (0 to 20 inches thick)

Cr--59 inches; soft shale or sandstone.

TYPE LOCATION: Montezuma County, CO; located about 400 feet south and 1,800 feet west of the NE corner of sec. 27, T. 36 N., R. 19 W.; Bowdish Canyon, CO USGS quad; lat. 108 degrees 55 minutes 40 seconds N. and long. 37 degrees 21 minutes 19 seconds W., NAD 27

RANGE IN CHARACTERISTICS:

Soil moisture regime: Typic aridic moisture regime.

Soil temperature regime: mesic

Mean annual soil temperature: 52 to 59 degrees F.

Surface rock fragments: 1 percent stones and 5 to 15 percent gravel

Particle-size control section: 35 to 60 percent clay

Depth to paralithic contact: 40 to 60 inches

Depth to secondary calcium carbonate: 20 to 40 inches

Depth to gypsiferous material: 40 to 60 inches

Vertic features: This soil has a linear extensibility of 6.0 cm or more between the soil surface and a depth of 100 cm.

Water table: none

A horizon
Hue: 5YR or 7.5YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 3 or 4
Texture: clay loam
Rock fragments: 0 to 20
Calcium carbonate equivalent: 1 to 5 percent
EC (mmhos/cm): 1 to 4
SAR: 0 to 10
Reaction: moderately alkaline

B horizon
Hue: 5YR or 7.5YR
Value: 5 to 7 dry, 5 or 6 moist
Chroma: 3 to 6
Texture: clay loam, silty clay loam, or clay
Rock fragments: 0 to 15 percent
Calcium carbonate equivalent: 4 to 12 percent
EC (mmhos/cm): 1 to 16
SAR: 15 to 50
Gypsum: 0 to 15 percent
Reaction: moderately or strongly alkaline

COMPETING SERIES: These are the Aguilar (CO), Churchill (NV) and Final (OR) series. Aguilar, Churchill and Final soils are very deep.

GEOGRAPHIC SETTING:

Parent material: Slope alluvium over residuum derived from Morrison shale.

Landform: Footslopes and toeslopes of hills.

Slopes: 3 to 9 percent

Elevation: 5,000 to 5,700 feet

Mean annual temperature: 52 to 56 degrees F.

Mean annual precipitation: 8 to 10 inches.

Frost-free period: 135 to 160 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Zwicker and Claysprings series. Zwicker and Claysprings soils are found on hills, knobs, and ridges and are usually located in geographically higher positions. Uzacol soils are normally in the footslope or toeslope position. Rock outcrop is also common in areas of Uzacol soils.

DRAINAGE AND PERMEABILITY: well drained, high runoff, slow permeability.

USE AND VEGETATION: Uzacol soils are used for wildlife habitat and livestock grazing. The present vegetation is shadscale, alkali sacaton, prickly pear, and galleta

DISTRIBUTION AND EXTENT: Southwest Colorado. LRR D, MLRA 35. This series is of small extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona

SERIES ESTABLISHED: Cortez Area, Colorado, Parts of Dolores and Montezuma Counties 1999.

REMARKS: Diagnostic horizons and features recognized in this pedon are:

Ochric epipedon: The zone from 0 to 5 inches.

Argillic horizon: The zone from 5 to 31 inches.

Natric horizon: The zone from 5 to 31 inches.

Vertic feature: This soil has a linear extensibility between the surface and 100 cm of more than 6 cm.

Classified according to Soil Taxonomy Second Edition, 1999; Keys to Soil Taxonomy Tenth Edition, 2006.

ADDITIONAL DATA: Lab sampled by NSSL 80CO-083-003.


National Cooperative Soil Survey
U.S.A.