LOCATION TAQOCI COEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, active, mesic Typic Natrigypsids
TYPICAL PEDON: Taqoci very fine sandy loam, on a southeast facing, 4 percent slope in rangeland at an elevation of 5,020 feet. (Colors are for dry soil unless otherwise noted.)
A--0 to 3 inches; light brown (7.5YR 6/4) very fine sandy loam, brown (7.5YR 4/4) moist; moderate coarse platy structure parting to moderate very fine granular; soft, very friable, nonsticky and nonplastic; many very fine and few fine roots throughout; 4 percent calcium carbonate equivalent; 4 percent igneous and sedimentary gravel; strongly effervescent; strongly alkaline (pH 8.6); abrupt smooth boundary. (1 to 6 inches thick)
BA--3 to 9 inches; brown (7.5YR 5/4) very fine sandy loam, brown (7.5YR 4/4) moist; moderate very thick platy structure parting to weak medium subangular blocky; slightly hard, friable, slightly sticky and slightly plastic; many very fine roots throughout; many very fine dendritic tubular pores; few distinct clay films on vertical faces of peds; few fine cylindrical masses of carbonate; 5 percent calcium carbonate equivalent; 4 percent igneous and sedimentary gravel; strongly effervescent; moderately alkaline (pH 8.3); clear smooth boundary.
Btkn1--9 to 14 inches; brown (7.5YR 5/4) clay loam, brown (7.5YR 4/4) moist; moderate very coarse prismatic structure parting to moderate medium subangular blocky; very hard, extremely firm, moderately sticky and moderately plastic; few very fine roots throughout; common very fine and few medium dendritic tubular pores; common distinct clay films on faces of peds; common medium irregular masses of carbonate; 16 percent calcium carbonate equivalent; SAR 9; 1 percent igneous and sedimentary gravel; strongly effervescent; strongly alkaline (pH 9.0); clear smooth boundary. (6 to 25 inches thick Btkn horizons)
Btkn2--14 to 26 inches; light brown (7.5YR 6/4) sandy clay loam, brown (7.5YR 5/4) moist; moderate very coarse prismatic structure parting to moderate medium subangular blocky and moderate fine angular blocky; very hard, extremely firm, very sticky and very plastic; few very fine roots throughout; common very fine and few medium dendritic pores; common distinct clay films on faces of peds; many medium irregular masses of carbonate; 15 percent calcium carbonate equivalent; SAR 20; 3 percent igneous and sedimentary gravel; strongly effervescent; very strongly alkaline (pH 9.1); clear smooth boundary.
Bkn--26 to 37 inches; light brown (7.5YR 6/4) very fine sandy loam, brown (7.5YR 4/4) moist; moderate very coarse prismatic structure parting to moderate medium angular blocky; slightly hard, friable, slightly sticky and slightly plastic; many very fine dendritic tubular pores; few distinct clay films on faces of peds; common medium irregular masses of carbonate; 9 percent calcium carbonate equivalent; SAR 18; 5 percent igneous and sedimentary gravel; strongly effervescent; moderately alkaline (pH 8.3); clear wavy boundary. (0 to 15 inches thick)
2Bkny1--37 to 52 inches; very pale brown (10YR 7/4) sandy clay loam, light yellowish brown (10YR 6/4) moist; weak very coarse prismatic structure parting to moderate medium angular blocky; slightly hard, friable, slightly sticky and slightly plastic; many very fine dendritic tubular pores; very few distinct clay films on faces of peds; common fine irregular masses of carbonate; many fine irregular nests of gypsum; 11 percent calcium carbonate equivalent; 5 percent gypsum; SAR 16; 5 percent igneous and sedimentary gravel; strongly effervescent; moderately alkaline (pH 8.2); clear smooth boundary. (20 to 70 inches thick 2Bkny horizons)
2Bkny2--52 to 73 inches; very pale brown (10YR 7/4) extremely gravelly sandy loam, light yellowish brown (10YR 6/4) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; common very fine interstitial pores; common medium irregular masses of carbonate; common fine irregular nests of gypsum; 14 percent calcium carbonate equivalent; 2 percent gypsum; SAR 14; 80 percent gravel and 5 percent cobbles (igneous and sedimentary); strongly effervescent; moderately alkaline (pH 8.1); clear smooth boundary.
2Bkny3--73 to 94 inches; very pale brown (10YR 7/4) very gravelly coarse sandy loam, light yellowish brown (10YR 6/4) moist; single grain; loose, loose, nonsticky and nonplastic; few very fine interstitial pores; common fine irregular masses of carbonate; few fine irregular gypsum crystals on bottom of rock fragments; 22 percent calcium carbonate; 12 percent gypsum; SAR 9; 50 percent gravel and 1 percent cobbles (igneous and sedimentary); strongly effervescent; moderately alkaline (pH 8.0); abrupt smooth boundary.
2Bkm--94 to 100 inches; petrocalcic very gravelly coarse sandy loam, massive; indurated; many fine and very fine interstitial pores; sand grains and gravel cemented with carbonates; 37 percent calcium carbonate; 0 percent gypsum; SAR 10; 50 percent igneous gravel and 2 percent igneous cobbles; strongly effervescent.
TYPE LOCATION: Montezuma County, Colorado; about 14 miles southwest of Towaoc, Colorado; Mariano Wash West, Colorado USGS quad; lat. 37 degrees 08 minutes 49 seconds N. and long. 108 degrees 58 minutes 08 seconds W., NAD 27.
RANGE IN CHARACTERISTICS:
Soil moisture regime: Typic aridic
Mean annual soil temperature: 54 to 58 degrees F
Depth to argillic horizon: 2 to 10 inches
Depth to secondary calcium carbonate: 2 to 10 inches
Depth to calcic horizon: 8 to 20 inches
Depth to gypsum accumulations: 20 to 40 inches
Depth to gypsic horizon: 20 to 40 inches
Depth to natric horizon: 2 to 20 inches
Particle-size control section (weighted average):
Clay content: 18 to 27 percent
Rock fragments: 0 to 15 percent
A horizon:
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 3 or 4, dry or moist
Texture: very fine sandy loam, loam
Clay content: 8 to 15 percent
Rock fragments: 0 to 10 gravel
Calcium carbonate equivalent: 2 to 15 percent
Gypsum: 0 to 1 percent
Reaction: moderately alkaline, strongly alkaline
Btkn and Bkn horizon:
Value: 5 to 7 dry, 4 or 5 moist
Chroma: 3 or 4, dry or moist
Texture: loam, clay loam, sandy clay loam, very fine sandy loam
Clay content: 18 to 35 percent
Rock fragments: 0 to 15 percent gravel
EC (mmhos/cm): 2 to 8
Calcium carbonate equivalent: 10 to 20 percent
Gypsum: 0 to 5 percent
SAR: 13 to 30
Reaction: strongly alkaline or very strongly alkaline
2Bkny horizon:
Value: 6 or 7 dry, 5 or 6 moist
Chroma: 3 or 4, dry or moist
Texture: sandy loam, loam
Clay content: 5 to 27 percent
Rock fragments: 5 to 50 percent gravel and cobbles
EC (mmhos/cm): 8 to 16
Calcium carbonate equivalent: 10 to 15 percent
Gypsum: 1 to 15 percent
Reaction: moderately alkaline
COMPETING SERIES: This is the Benally series. Benally soils have a paralithic contact of weathered sandstone below 40 inches and do not have a diagnostic calcic horizon.
GEOGRAPHIC SETTING:
Parent material: eolian deposits derived from sandstone over old alluvium derived from igneous sources
Landform: paleoterraces and fan remnants
Slopes: 2 to 6 percent
Elevation: 4,800 to 5,700 feet
Mean annual temperature: 52 to 56 degrees F
Mean annual precipitation: 7 to 10 inches
Precipitation pattern: uniform with slight dip in May and June and slight increase in July and August
Frost-free period: 135 to 160 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Gypsey, Persayo, and Yogovuci series. The Gypsey soils are moderately deep to shale, and the Persayo soils are shallow to shale. Both are on pediments. The Yogovuci soils lack a natric horizon and are on fan remnants.
DRAINAGE AND PERMEABILITY: Well drained, medium or high runoff, moderately slow permeability.
USE AND VEGETATION: The Taqoci soils are used mainly as grazing land and, to a limited extent, irrigated agriculture. Native vegetation is galleta, shadscale, alkali sacaton, and Indian ricegrass.
DISTRIBUTION AND EXTENT: Southwest Colorado; MLRA 35. This series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona.
SERIES ESTABLISHED: Montezuma County, Colorado, Ute Mountain Area, Colorado and New Mexico, 2005.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Series control section: The zone from 0 to 79 inches.
Particle-size control section: The zone from 9 to 26 inches. (Btk and Btkn horizons)
Ochric epipedon: The zone from 0 to 9 inches. (A and BA horizons)
Argillic horizon: The zone from 9 to 26 inches. (Btkn1 and Btkn2 horizons)
Natric horizon: The zone from 9 to 26 inches. (Btkn1 and Btkn2 horizons)
Calcic horizon: The zone from 9 to 26 inches. (Btkn1, Btkn2 horizons)
Gypsic horizon: The zone from 37 to 52 inches. (2Bkny1 horizon)
Lithologic discontinuity: At the upper boundary of the 2Bkny2 horizon, at the contact between the eolian material and the underlying alluvial material
ADDITIONAL DATA: The typical pedon for Taqoci was sampled by NSSL for full characterization, sample S99CO-083-04.
Classified according to Soil Taxonomy, Second Edition, 1999; Keys to Soil Taxonomy, Tenth Edition, 2006.
Revisions and updated competing series section 2/26/08 DWD