LOCATION TOQUI AZEstablished Series
TAXONOMIC CLASS: Clayey, smectitic, mesic Lithic Haplustalfs
TYPICAL PEDON: Toqui fine sandy loam - grazable woodland. (Colors are for dry soil unless otherwise noted.)
A1--0 to 1 inch; brown (7.5YR 5/4) fine sandy loam, brown (7.5YR 4/4) moist; weak fine granular structure; soft, very friable, nonsticky and nonplastic; many fine roots; many very fine tubular pores; 5 percent fine gravel; slightly acid (pH 6.5); abrupt smooth boundary. (0 to 1 inch thick)
A2--1 to 3 inches; light yellowish brown (10YR 6/4) very fine sandy loam, dark yellowish brown (10YR 4/4) moist; weak thin platy structure; soft, very friable, nonsticky and nonplastic; few fine roots; many very fine vesicular pores; slightly acid (pH 6.5); abrupt smooth boundary. (1 to 3 inches thick)
Bt1--3 to 5 inches; reddish brown (5YR 4/4) clay loam, dark reddish brown (5YR 3/4) moist; weak fine subangular blocky structure; slightly hard, friable, sticky and plastic; common very fine and fine roots; many very fine and few fine tubular pores; few faint clay films on faces of peds; 5 percent gravel; neutral (pH 7.0); clear smooth boundary. (1 to 2 inches thick)
Bt2--5 to 12 inches; reddish brown (5YR 4/4) clay, dark reddish brown (5YR 3/4) moist; common fine and moderate subangular blocky structure; very hard, firm, very sticky and very plastic; common very fine and few coarse roots; common very fine tubular pores; many distinct clay films on faces of peds; 5 percent gravel; moderately alkaline (pH 7.9); gradual smooth boundary. (4 to 14 inches thick)
Bk1--12 to 15 inches; reddish brown (5YR 5/4) clay loam, dark reddish brown (5YR 3/4) moist; weak fine subangular blocky structure; hard, firm, sticky and plastic; common very fine and few fine roots; common very fine tubular pores; 10 percent gravel; moderately alkaline (pH 7.9); clear smooth boundary. (0 to 3 inches thick)
Bk2--15 to 19 inches; reddish brown (5YR 5/4) very gravelly clay loam, reddish brown (5YR 4/4) moist; massive; hard, firm, sticky and plastic; common very fine and fine roots; few fine pores; 45 percent gravel; strongly effervescent; moderately alkaline (pH 8.0); abrupt smooth boundary. (0 to 4 inches thick)
R--19 inches; limestone.
TYPE LOCATION: Coconino County, Arizona; about 10 miles southwest of the Grand Canyon Village, 1,000 feet east and 1,000 feet south of the northwest corner of section 16, T. 30 N., R. 1 E.
RANGE IN CHARACTERISTICS:
Soil moisture: Is dry in some part for 90 or more days cumulative and is moist in some part for 45 consecutive days during June through October and more than half the time that the soil temperature is above 41 degrees F. Driest during May and June. Aridic ustic soil moisture regime.
Soil temperature: 49 to 56 degrees F.
Depth to bedrock: 8 to 20 inches
Other features: Some pedons may not have a lithologic discontinuity between the surface and subsurface horizons.
A1 horizon
Hue: 5YR, 7.5YR
Value: 3 to 6 dry, 3 or 4 moist
Chroma: 3 to 8, dry or moist
Reaction: slightly acid to slightly alkaline
A2 horizon
Hue: 7.5YR, 10YR
Value: 3 to 6 dry, 2 to 5 moist
Chroma: 2 to 8, dry or moist
Rock fragments: 0 to 85 percent gravel and 0 to 10 percent cobble
Reaction: slightly acid to moderately alkaline
Bt horizon
Hue: 2.5YR, 5YR, 7.5YR
Value: 3 to 5 dry, 3 or 4 moist
Chroma: 3 to 6, dry or moist
Texture: clay loam, clay, loam
Rock Fragments: 0 to 35 percent gravel and 0 to 5 percent cobble
Clay content: ranges from 20 to 50 percent; averages greater than 35 percent in the particle size control section
Bk horizon (when present)
Hue: 5YR, 7.5YR, 10YR
Value: 5 to 8 dry, 4 to 7 moist
Chroma: 2 to 4, dry or moist
Texture: loam, clay loam (25 to 35 percent clay)
Rock Fragments: 15 to 50 percent gravel and cobble
Calcium carbonate equivalent: 15 to 45 percent
COMPETING SERIES: This is the
Sarcillo (CO) series.
Sarcillo soils are moist in the soil moisture control section during
May and June and do not have calcic horizon.
GEOGRAPHIC SETTING: Toqui soils are on plateaus and mesas at elevations of 5,000 to 7,500 feet. They formed in residuum; alluvium and eolian material derived from calcareous sandstone and limestone. Slopes range from 0 to 30 percent. The mean annual precipitation is 14 to 18 inches. The mean annual air temperature is 47 to 54 degrees F. The frost-free period is 100 to 160 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Boysag, Disterheff, Lynx, Rune and Yumtheska soils. Boysag soils have an aridic moisture regime. Yumtheska soils do not have an argillic horizon. Disterheff, Lynx and Rune soils are very deep.
DRAINAGE AND PERMEABILITY: Well drained; slow runoff; slow permeability.
USE AND VEGETATION: Toqui soils are used for livestock grazing and fuelwood production. Present vegetation is pinyon and Utah juniper, Wyoming big sagebrush, galleta, and rabbitbrush.
DISTRIBUTION AND EXTENT: North central Arizona. This series is of moderate extent. MLRA 35.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Coconino County Area, Arizona, Central Part; 1980.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from 0 to 3 inches (A1, A2 horizons)
Argillic horizon - The zone from 3 to 12 inches (Bt1, Bt2 horizons)
Lithic contact - The boundary at 19 inches (R horizon)
The classification of this soil is changed from mixed to montmorillonitic based on NSSL mineralogy data for adjacent soils. The type location has not been changed.
Classified according to Soil Taxonomy Second Edition, 1999; Keys to Soil Taxonomy Tenth Edition, 2006.