LOCATION TENSED                  ID

Established Series
Rev. AEK/AVY/MPR
11/2013

TENSED SERIES

The Tensed series consists of very deep, moderately well drained soils that formed in colluvium or tertiary alluvium from metasedimentary rocks and mixed with loess and an influence of volcanic ash in the upper part. Tensed soils are on dissected terraces and foothills. Slopes range from 3 to 35 percent. The mean annual precipitation is about 24 inches. The mean annual temperature is about 44 degrees F.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Vitrandic Argixerolls

TYPICAL PEDON: Tensed silt loam, cultivated, on a 4 percent slope at 2,913 feet elevation. (Colors are for dry soil unless otherwise noted.) When re-described on October 26, 2011, the soil was dry to 24 inches and slightly moist below.

Ap1--0 to 4 inches; brown (7.5YR 5/3) ashy silt loam, very dark brown (7.5YR 2.5/2) moist; moderate fine subangular blocky parting to strong coarse granular; slightly hard, friable, nonsticky, slightly plastic; many very fine and few fine roots; many very fine and common fine pores; 2 percent fine, rounded quartzite gravel; thin layer of 1980 Mount St. Helens ash; strongly acid (pH 5.3); clear wavy boundary.

Ap2--4 to 7 inches; brown (7.5YR 5/3) ashy silt loam, very dark brown (7.5YR 2.5/3), moist; moderate medium subangular blocky structure; slightly hard, friable, nonsticky, slightly plastic; common very fine and few fine roots; many very fine and common fine pores; 3 percent fine, rounded quartzite gravel; strongly acid (pH 5.1); clear wavy boundary. (combined Ap horizons are 7 to 12 inches thick)

BA--7 to 12 inches; brown (10YR 5/3) silt loam, dark brown (10YR 3/3), moist; weak coarse subangular blocky parting to strong medium subangular blocky; slightly hard, friable, nonsticky, moderately plastic; common very fine and few fine, medium and coarse roots; many very fine and fine pores; 2 percent faint clay films on surfaces along pores; 5 percent fine rounded quartzite gravel; strongly acid (pH 5.5); abrupt wavy boundary. (4 to 8 inches thick)

EB--12 to 22 inches; light yellowish brown (10YR 6/4) gravelly silt loam, dark yellowish brown (10YR 4/4) moist; strong medium subangular blocky structure; slightly hard, friable, slightly sticky, moderately plastic; common very fine and few fine, medium and coarse roots; many very fine and fine pores; 4 percent faint clay films on faces of peds and on surfaces along pores; 3 percent fine faint iron-manganese masses in matrix; 10 percent fine and 5 percent medium rounded quartzite gravel; moderately acid (pH 5.7); clear wavy boundary. (8 to 12 inches thick)

E--22 to 24 inches; very pale brown (10YR 7/3) gravelly loam, yellowish brown (10YR 5/4) moist; weak medium subangular blocky structure; slightly hard, friable, nonsticky, slightly plastic; few very fine, fine, medium and coarse roots; many very fine and common fine pores; 25 percent distinct silt coats on all faces of peds; 3 percent fine faint iron depletions and 5 percent fine faint iron-manganese masses and 3 percent fine iron-manganese concretions in matrix; 10 percent fine and 5 percent medium rounded quartzite gravel; moderately acid (pH 5.8); abrupt wavy boundary. (2 to 5 inches thick)

2Bt1--24 to 36 inches; strong brown (7.5YR 5/6) very gravelly clay loam, strong brown (7.5YR 4/6) moist; moderate medium prismatic structure parting to strong medium subangular blocky; hard, very firm, very sticky, very plastic; few very fine, fine and medium roots; common very fine pores; 35 percent prominent clay films on faces of peds and on surfaces along pores and 5 percent prominent organoargillans on surfaces along root channels; 5 percent medium faint iron-manganese masses and 3 percent fine iron-manganese concretions in matrix; 25 percent fine and 15 percent medium rounded quartzite gravels, and 5 percent rounded quartzite cobbles; moderately acid (pH 5.6); gradual wavy boundary. (7 to 10 inches thick)

2Bt2--36 to 58 inches; yellowish brown (10YR 5/6) clay loam, dark yellowish brown (10YR 4/6), moist; weak coarse prismatic structure parting to moderate coarse subangular blocky; hard, very firm, moderately sticky, very plastic; few fine roots between peds; many very fine interstitial pores; 25 percent prominent clay films on faces of peds and on surfaces along pores and 10 percent distinct clay films between sand grains; 10 percent distinct silt coats and 5 percent faint sand coats on faces of peds; 3 percent prominent organoargillans on surfaces along root channels; 5 percent medium faint iron-manganese masses and 3 percent fine iron-manganese concretions in matrix; 10 percent fine and 2 percent medium rounded quartzite gravels, and 2 percent rounded quartzite cobbles; neutral (pH 7.3); clear wavy boundary. (15 to 25 inches thick)

2Bt3--58 to 61 inches; light yellowish brown (10YR 6/4) very gravelly sandy clay loam, yellowish brown (10YR 5/4) moist; weak medium subangular blocky structure; moderately hard, firm, slightly sticky, moderately plastic; 15 percent distinct clay films on faces of peds and on surfaces along pores; 5 percent faint clay films between sand grains; 5 percent distinct silt coats and 10 percent distinct sand coats on faces of peds; 3 percent fine iron-manganese concretions in matrix; 25 percent fine and 25 percent medium rounded quartzite gravels, and 5 percent rounded quartzite cobbles; neutral (pH 7.3).

TYPE LOCATION: Benewah County, Idaho; about 2.6 miles east of Tensed; 1,600 feet north and 700 feet east of southwest corner section 9, T.44N., R.4W. Latitude 47 degrees 10 minutes, 3.0 seconds North; Longitude 116 degrees 51 minutes, 1.84 seconds West; NAD 83. USGS Benewah, Idaho topographic quadrangle.

RANGE IN CHARACTERISTICS:
Thickness of mollic epipedon - 12 to 20 inches
Average annual soil temperature - 41 to 47 degrees F
Average summer soil temperature - 59 to 61 degrees F without an O horizon (frigid temperature regime)
Moisture control section - usually dry for 45 to 60 consecutive days following the summer solstice (xeric moisture regime)
Particle size control section - weighted average rock fragment content is 10 to 35 percent

Ap horizons (A horizons when present)
Hue - 10YR or 7.5YR
Value - 4 or 5 dry, 2 or 3 moist
Chroma - 2 or 3, dry or moist
Texture - Ashy SIL
Clay content - 10 to 20 percent
Gravel content - 0 to 15 percent
Cobble content - 0 to 5 percent
Total rock fragment content - 0 to 15 percent
Reaction - strongly acid to slightly acid

BA horizon
Hue - 10YR or 7.5YR
Value - 4 or 5 dry, 2 or 3 moist
Chroma - 2 to 4, dry, 2 or 3 moist
Texture - SIL, L
Clay content - 12 to 20 percent
Gravel content - 0 to 20 percent
Cobble content - 0 to 5 percent
Total rock fragment content - 0 to 20 percent
Reaction - strongly acid to slightly acid

E and EB horizons
Hue - 10YR
Value - 6 to 8 dry, 4 or 5 moist
Chroma - 2 to 4, dry or moist
Texture - SIL, L, FSL
Clay content - 5 to 20 percent
Gravel content - 0 to 20 percent
Cobble content - 0 to 5 percent
Total rock fragment content - 0 to 20 percent
Reaction - moderately acid to neutral

2Bt horizons (upper part)
Hue - 10YR or 7.5YR
Value - 4 to 6 dry, 4 or 5 moist
Chroma - 4 to 6, dry or moist
Texture - CL, L, SCL, SICL
Clay content - 25 to 38 percent
Gravel content - 10 to 40 percent
Cobble content - 0 to 10 percent
Total rock fragment content - 10 to 45 percent; "stone lines" range up to 65 percent rock fragments
Reaction - moderately acid to neutral

2Bt horizons (lower part)
Hue - 10YR or 7.5YR
Value - 4 to 6 dry, 4 or 5 moist
Chroma - 4 to 6, dry or moist
Texture - CL, L, SCL
Clay content - 22 to 35 percent
Gravel content - 30 to 55 percent
Cobble content - 0 to 15 percent
Total rock fragment content - 30 to 65 percent
Reaction - moderately acid to neutral

COMPETING SERIES:
These are the Fastjet, Luckycreek, Pagecreek, Pinney, Powellbutte, Runyon and Tommycork soils. The Fastjet soils are 20 to 40 inches deep to a lithic contact (volcanic rock). The Luckycreek soils are dry for 75 to 100 consecutive days. Pagecreek soils have horizons with secondary carbonates. Pinney soils formed in lacustrine deposits without loess. Powellbutte, Runyon and Tommycork soils are 20 to 40 inches deep to a lithic contact (volcanic rock).

GEOGRAPHIC SETTING: Tensed soils are on dissected terraces and foothills at elevations of 2,500 to 3,200 feet. Slopes range from 3 to 35 percent. The soils formed in colluvium and tertiary alluvium derived from metasedimentary rocks of the Belt series with a mixture of loess and volcanic ash in the upper part of the profile. The average annual precipitation is 23 to 27 inches, including 4 to 5 feet of snowfall. The average annual temperature is 43 to 46 degrees F. The frost free period is 90 to 130 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Pedee, Setters and Taney soils. Pedee soils are clayey-skeletal and are on adjacent dissected terraces and foothills. Setters soils are fine textured and on adjacent dissected terraces and hills. Taney soils have a fragipan and are on adjacent dissected terraces and hills.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Moderately well drained; saturated hydraulic conductivity is moderately high in the upper part and moderately low in the lower part. There is a seasonally perched water table at a depth of 22 to 30 inches from February to April.

USE AND VEGETATION: Used mainly for crop production and timber production. The primary crops are small grains, hay and pasture. The natural overstory is Douglas-fir and ponderosa pine. The understory is ninebark, oceanspray, common snowberry, white spiraea, Nootka rose, Woods rose, pine grass, bedstraw and Columbia brome.

DISTRIBUTION AND EXTENT: Benewah County, Idaho, MLRA 9. The series is of small extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon

SERIES ESTABLISHED: Benewah County, Idaho, 1975.

REMARKS:
Diagnostic horizons and other features recognized in this pedon are:
Mollic epipedon - the zone from 0 to 12 inches (Ap1, Ap2 and BA horizons)
Cambic horizon - the zones from 12 to 22 inches (EB horizon)
Argillic horizon - the zone from 24 to 60 inches (2Bt1, 2Bt2 and 2Bt3 horizons)
Particle-size control section - the upper 20 inches of the argillic horizon (the zone from 24 to 44 inches)
Vitrandic feature assumed based on surrounding soils; MLRA investigation needed to determine extent of vitrandic influence for this series.

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National Cooperative Soil Survey
U.S.A.