LOCATION AHSAHKA            ID
Established Series
Rev. PNP-GAH-BG-JAL
12/2002

AHSAHKA SERIES


The Ahsahka series consists of very deep, well drained soils formed in loess and a mixture of alluvium and material weathered from granitic rock. Ahsahka soils are on benches, hills, canyon sideslopes and footslopes and have slopes of 5 to 75 percent. Permeability is slow. The average annual precipitation is about 23 inches, and the average annual temperature is about 47 degrees F.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Typic Argixerolls

TYPICAL PEDON: Ahsahka silt loam - on a 36 percent northwest slope at an elevation of 1280 feet - sparsely forested. (Colors are for dry soil unless otherwise noted).

A--0 to 6 inches; dark grayish brown (10YR 4/2) silt loam, very dark brown (10YR 2/2) moist; weak fine subangular blocky structure parting to moderate fine and medium granular; slightly hard, very friable, slightly sticky and slightly plastic; many very fine and fine and common medium roots throughout; common fine and medium and few coarse irregular pores; slightly acid (pH 6.4); clear wavy boundary. (4 to 11 inches thick)

AB--6 to 16 inches; brown (10YR 4/3) silt loam, dark brown (10YR 3/3) moist; moderate fine and medium subangular blocky structure parting to strong medium granular; slightly hard, very friable, slightly sticky and slightly plastic; many very fine and fine, common medium and few coarse roots throughout; common very fine tubular and common fine irregular pores; neutral (pH 6.8); clear wavy boundary. (0 to 11 inches thick)

Bt1--16 to 22 inches; yellowish brown (10YR 5/4) loam, dark yellowish brown (10YR 3/4) moist; moderate fine and medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine and fine, common medium and few coarse roots throughout; common very fine tubular and common fine and medium irregular pores; few faint clay films in pores; neutral (pH 6.9); clear wavy boundary.

Bt2--22 to 35 inches; yellowish brown (10YR 5/4) loam, dark yellowish brown (10YR 3/4) moist; strong fine and medium subangular blocky structure; moderately hard, friable, moderately sticky and moderately plastic; common very fine, fine and medium roots throughout; common very fine tubular and few very fine irregular pores; few faint clay films on faces of peds and in pores; neutral (pH 6.9); abrupt wavy boundary (Bt horizons 15 to 47 inches thick)

2Bt3--35 to 43 inches; brown (7.5YR 4/4) clay, dark brown (7.5YR 3/4) moist; strong fine angular blocky structure; moderately hard, firm, very sticky and very plastic; few very fine, fine and medium roots throughout; few very fine tubular and few very fine irregular pores; few distinct clay films in pores; neutral (pH 6.6); clear wavy boundary.

2Bt4--43 to 51 inches; brown (7.5YR 5/4) clay, dark brown (7.5YR 3/4) moist; weak fine and medium subangular blocky structure; moderately hard, firm, very sticky and very plastic; few very fine, fine and medium roots throughout; common very fine tubular pores; common distinct clay films in pores; neutral (pH 6.9); clear wavy boundary.

2Bt5--51 to 60 inches; brown (7.5YR 5/4) silty clay loam, dark brown (7.5YR 3/4) moist; moderate fine and medium subangular blocky structure; very hard, very firm, moderately sticky and moderately plastic; few very fine and fine roots throughout; many very fine tubular pores; common distinct clay films in pores; 5 percent gravel; neutral (pH 7.1).

TYPE LOCATION: Clearwater County, Idaho; about 0.5 miles north of Orofino, Idaho; about 1825 feet east and 800 feet north of the southwest corner of section 6, T.36 N., R. 2 E.; Latitude - 46 degrees, 29 minutes, 17 seconds North; Longitude - 116 degrees, 15 minutes, 22 seconds West. USGS Orofino West Quadrangle.

RANGE IN CHARACTERISTICS:

Thickness of mollic epipedon - 10 to 20 inches
Average annual soil temperature - 47 to 54 degrees F.

A Horizon
Hue - 7.5YR or 10YR moist
Value - 3 to 5 dry, 2 or 3 moist
Chroma - 1 to 3 dry or moist
Textures - L, SIL
Clay content - 16 to 23 percent
Rock fragments - 0 to 5 percent gravel
Reaction - moderately acid to neutral

AB or BA horizons
Hue - 7.5YR or 10YR moist
Value - 4 to 6 dry, 3 or 4 moist
Chroma - 2 or 3 dry, 2 to 4 moist
Textures - L, SIL, SICL
Clay content - 17 to 33 percent
Rock fragments - 0 to 5 percent gravel
Reaction - moderately acid to neutral

Bt horizons
Hue - 10YR or 7.5YR dry or moist
Value - 3 to 6 dry, 3 or 5 moist
Chroma - 2 to 4 dry or moist
Textures - L, SIL, SICL, CL, GR-CL
Clay content - 16 to 38 percent
Coarse fragments - 0 to 25 percent gravel, 0 to 5 percent cobbles, 0 to 30 percent total rock fragment content
Reaction - slightly acid to slightly alkaline

2Bt horizons (absent in some pedons)
Hue - 7.5YR or 10YR
Value - 3 to 6 dry, 3 to 5 moist
Chroma - 2 to 6 dry or moist
Textures - C, SIC, SICL, CL, GR-SICL
Clay content - 30 to 60 percent
Coarse fragments - 0 to 15 percent gravel, 0 to 5 percent cobbles, 0 to 15 percent total rock fragments
Reaction - moderately acid to neutral

2BC horizons (where present)
Hue - 5YR to 10YR dry, 7.5YR or 10YR moist
Value - 4 or 5 dry or moist
Chroma - 4 or 6 dry or moist
Textures - CL, GR-L
Clay content - 24 to 36 percent
Rock fragments - 10 to 15 percent gravel
Reaction - neutral

COMPETING SERIES: These are the Buckbay(T), Colma, Currymountain, Dragnot(T), Duzel, Elkheights(T), Facey, Farrot, Foehlin, Hatspring(T), Immiant, Jauriga(T), Ladd, Lobitos, Los Gatos, Mehlhorn, Picketpin, Pittville, Sagaser, Taneum, Tieton, Tweedy and Vollmer series. Buckbay, Dragnot, Farrot, Hatspring, Immiant, Lobitos, Los Gatos, Mehlhorn, and Vollmer soils are 20 to 40 inches deep to bedrock. Colma, Facey, Ladd, Taneum and Tieton soils are 40 to 60 inches deep to bedrock. Currymountain, Duzel and Tweedy soils are 20 to 40 inches deep to paralithic contact. Elkheights soils have a densic contact. Foehlin soils are stratified in the lower part of the particle size control section. Jauriga soils 40 to 60 inches to a paralithic contact. Picketpin soils have an E&B horizon with lamellae in the subsoil. Pittville soils have a Bq horizon. Sagaser soils are 40 to 60 inches to a paralithic contact.

GEOGRAPHIC SETTING: Ahsahka soils are on hills, canyon sideslopes, footslopes and benches at elevations of 1,000 feet to 3,100 feet and have slopes of 5 to 75 percent. These soils developed in loess and a mixture of alluvium and material weathered from granitic rock. The average annual temperature is 45 to 52 degrees F. The average annual precipitation is 21 to 26 inches and the frost-free season is 90 to 180 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Johnson, Spokane, and Whiskeycreek series. Johnson soils have loamy subsoils. Spokane soils are moderately deep to bedrock. Whiskeycreek soils are shallow to bedrock. All are on canyon sideslopes.

DRAINAGE AND PERMEABILITY: Well drained; runoff is rapid to very rapid; permeability is slow.

USE AND VEGETATION: This soil is used for livestock grazing, wildlife habitat and limited timber production. The natural vegetation is mainly widely spaced ponderosa pine, common snowberry, rose, bluebunch wheatgrass, and Idaho fescue.

DISTRIBUTION AND EXTENT: North central Idaho. The series is of small extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana

SERIES ESTABLISHED: Nez Perce County, Idaho, 1995.

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

Mollic epipedon - The zone from the mineral soil surface to 16 inches (A and AB horizons).

Argillic horizon - The zone from 16 to 60 inches (Bt1, Bt2 and 2Bt3, 2Bt4 and 2Bt5 horizons).

Particle-size control section - The zone from 16 to 36 inches (Bt1, Bt2 and upper part of the 2Bt3 horizons).

ADDITIONAL DATA: This series has laboratory data - field sample no. S88ID-035-001 (project no. 88P 167, pedon no. 88P 925), and field sample no. S92ID-035-100 (project no. 92P 112, pedon no. 92P 645) also sampled as Ahsahka series but classifying in a closely related family is field sample no. S91ID-035-001 (project no. 91P 119, pedon no. 91P 679) all Clearwater County, Idaho by NSSL, Lincoln NE.


National Cooperative Soil Survey
U.S.A.