LOCATION ISHKOTEN                NM+CO

Established Series
Rev. RLB/TWH/KLS
03/2018

ISHKOTEN SERIES

The Ishkoten series consists of moderately deep, well drained soils that formed in slope alluvium or colluvium over residuum derived from shale and sandstone. Ishkoten soils are on hillslopes and mountain slopes. Slopes range from 3 to 65 percent. The mean annual precipitation is about 457 mm and the mean annual temperature is about 6.1 degrees C.

TAXONOMIC CLASS: Fine, smectitic, frigid Typic Haplustalfs

TYPICAL PEDON: Ishkoten cobbly sandy loam, on a west facing, convex 33 percent slope in ponderosa pine woodland at an elevation of 2,438 meters. (Colors are for dry soil unless otherwise noted.) When described on July 7, 1999 the soil was moist throughout.

Oi--0 to 3 cm; slightly decomposed pine and oak litter. (0 to 5 cm thick)

A--3 to 15 cm; brown (10YR 5/3) cobbly sandy loam, very dark grayish brown (10YR 3/2) moist; weak fine granular structure; soft, very friable, nonsticky and nonplastic; few very fine roots; 5 percent stones, 15 percent cobble, and 5 percent gravel; neutral (pH 6.8); clear smooth boundary. (5 to 18 cm thick)

Bt1--15 to 28 cm; brown (7.5YR 5/3) cobbly sandy clay, brown (7.5YR 4/3) moist; strong fine angular blocky structure; hard, firm, moderately sticky and moderately plastic; many very fine, fine and medium roots; many distinct clay films on ped faces; 10 percent cobble and 10 percent gravel; neutral (pH 6.8); clear smooth boundary. (10 to 18 cm thick)

Bt2--28 to 56 cm; brown (7.5YR 5/4) cobbly sandy clay, brown (7.5YR 4/4) moist; strong medium and fine angular blocky structure; hard, firm, moderately sticky and moderately plastic; common fine, medium, and coarse roots; common very fine tubular pores; many distinct clay films on ped faces; 7 percent cobble, 10 percent gravel; slightly acid (pH 6.4); gradual smooth boundary. (combined thickness of Bt1, Bt2 is 30 to 56 cm)

Bt3--56 to 86 cm; strong brown (7.5YR 5/6) sandy clay loam, strong brown (7.5YR 4/6) moist; moderate medium angular blocky structure; hard, firm, moderately sticky and moderately plastic; common fine, medium, and coarse roots; common very fine tubular pores; common distinct clay films on ped faces; slightly acid (pH 6.4); gradual smooth boundary.

Cr--86-122 cm; weakly cemented sandstone with faint clay films in cracks

TYPE LOCATION: Rio Arriba County, New Mexico, about 402 meters north of Wells Look Out tower, located 579 meters east and 604 meters south of the northwest corner of Section 29, T. 31 N., R 2 W. John Mills Lake USGS Quad; Lat. 36 degrees, 52 minutes, 18 seconds N. and Long. 107 degrees, 04 minutes, 07 seconds W., NAD 27.

RANGE IN CHARACTERISTICS: (Depths given are measured from the mineral soil surface)
Mean annual soil temperature: 5.6 to 7.2 degrees C.
Mean summer soil temperature: 15.0 to 16.7 degrees C.
Depth to the base of the argillic: 58 to 97 cm
Depth to paralithic contact: 50 to 100 cm
Rock fragments generally decrease with depth, para rock fragments increase with depth.

Particle-size control section (weighted average):
Clay content: 35 to 42 percent
Sand content 30 to 50 percent
Rock Fragments:
Content: 5 to 25 percent
Size: gravel, cobble, and stones
Kind: subrounded sandstone
Pararock fragments:
Content: 0 to 25 percent
Size: gravel or channers
Kind: noncalcareous subrounded shale fragments

A horizon
Hue: 7.5YR or 10YR
Value: 4 to 6 dry, 2 to 4 moist
Chroma: 2 to 4, dry or moist
Texture: sandy loam, loam, or sandy clay loam
Clay content: 16 to 22 percent
Rock fragments: 0 to 35 percent; sandstone gravel, cobbles, or stones
Reaction (pH): 6.1 to 7.3

Bt1 horizon
Hue: 7.5YR to 2.5Y
Value: 4 to 6 dry, 3 to 5 moist
Chroma: 2 to 4, dry or moist
Texture of the fine earth fraction: clay loam, sandy clay, or clay
Clay content: 35 to 45 percent
Rock fragment: 15 to 35 percent; sandstone or shale gravel, cobbles, or stones
Reaction (pH): 6.1 to 7.3

Bt2 horizon
Hue: 7.5YR to 2.5Y
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 4 to 6, dry or moist
Texture: clay loam, sandy clay, or clay
Clay content: 35 to 45 percent
Rock fragments: 0 to 35 percent; sandstone gravel, cobbles, or stones;
Reaction (pH): 6.1 to 7.3

Bt3 horizon
Hue: 7.5YR to 2.5Y
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 4 to 6, dry or moist
Texture: sandy clay loam, clay loam, or clay
Clay content: 30 to 45 percent
Rock fragments: 0 to 35 percent; sandstone gravel, cobbles, or stones
Reaction (pH): 6.1 to 7.3

COMPETING SERIES:
Burnac (NM) - are not moderately deep to paralithic or lithic contact
Burnson (CO) - are not moderately deep to paralithic or lithic contact
Campspass (MT) - are not moderately deep to paralithic or lithic contact
Goldbug (CO) - are not moderately deep to paralithic or lithic contact
Goldvale (CO) - are not moderately deep to paralithic or lithic contact
Larkson (CO) - are not moderately deep to paralithic or lithic contact
Loghill (CO) - are not moderately deep to paralithic or lithic contact
McVickers (AZ) - are not moderately deep to paralithic or lithic contact
Siesta (AZ) - are not moderately deep to paralithic or lithic contact
Spud (NM) - are not moderately deep to paralithic or lithic contact

GEOGRAPHIC SETTING:
Landform - hillslopes and mountain slopes
Elevation - 2,040 to 2,630 meters
Slopes - 3 to 65 percent
Parent material - slope alluvium or colluvium over residuum derived from sandstone and shale
Mean annual temperature - 5.6 to 7.2 degrees C.
Mean annual precipitation - 380 to 510 mm
Precipitation pattern - precipitation falls mostly during the months of November through March and July through October. June is the driest month. Total snowfall averages about 1.2 to 1.5 meters with snowmelt lasting into April.
Frost-free period - 80 to 110 days

GEOGRAPHICALLY ASSOCIATED SOILS: None listed.

DRAINAGE AND PERMEABILITY: Well drained; medium to high runoff; slow permeability.

USE AND VEGETATION: These soils are used for commercial woodlands, and wildlife habitat. Native vegetation is ponderosa pine, Gambel's oak, bitterbrush, Arizona fescue, snowberry, Douglas fir on North slopes and western wheatgrass.

DISTRIBUTION AND EXTENT: North central New Mexico, south central Colorado; LRRs D, E; MLRAs 36, 48A. The series is of small extent.

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Bozeman, Montana

SERIES ESTABLISHED: Rio Arriba County, Jicarilla Area, Parts of Rio Arriba and Sandoval Counties Soil Survey, New Mexico, 2000. The name Ishkoten is taken from the name of a local canyon.

REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Argillic horizon: 15 to 86 cm (Bt1, Bt2, Bt3 horizons)
Paralithic contact: 86 cm to soft sandstone bedrock (Cr layer)
Particle size control section: 15 to 65 cm (Bt1 and part of Bt2 horizon)

Ishkoten soils have a frigid temperature regime and are in an ustic soil moisture regime with a typic subclass.

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National Cooperative Soil Survey
U.S.A.