LOCATION BEAVERSLIDE MT

Established Series
Rev: PEM-KTS-RJS
03/2011

BEAVERSLIDE SERIES

The Beaverslide series consists of very deep, well drained soils that formed in mixed alluvium on stream terraces, fan remnants, alluvial fans and depressions. These soils are subject to prolonged saturation from flood irrigation. Slopes are 0 to 8 percent. Mean annual precipitation is about 16 inches, and mean annual air temperature is about 37 degrees F.

TAXONOMIC CLASS: Fine, mixed, superactive Oxyaquic Argicryolls

TYPICAL PEDON: Beaverslide silt loam, in irrigated grass hay (colors are for dry soil unless otherwise noted).

Oi--0 to 2 inches; undecomposed and partially decomposed matted roots; abrupt smooth boundary. (1 to 3 inches thick)

A1--2 to 7 inches; dark grayish brown (10YR 4/2) silt loam, black (10YR 2/1) moist; few medium and fine faint strong brown (7.5YR 4/6) moist redox concentrations (due to prolonged saturation from flood irrigation); moderate medium and fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and few fine roots; many fine and very fine dendritic tubular pores; 10 percent gravel; slightly acid (pH 6.5); clear wavy boundary.

A2--7 to 12 inches; brown (10YR 5/3) silt loam, dark brown (10YR 3/3) moist; common medium and fine faint strong brown (7.5YR 4/6) moist redox concentrations (due to prolonged saturation from flood irrigation); moderate medium and fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and few fine roots; many fine and very fine dendritic tubular pores; 10 percent gravel; neutral (pH 6.7); clear wavy boundary. (combined thickness of A horizons is 9 to 15 inches)

E/Bt--12 to 15 inches; E part (70 percent) light gray (10YR 7/1) silt loam, grayish brown (10YR 5/2) moist; Bt part (30 percent) brown (10YR 5/3) silt loam, brown (10YR 4/3) moist; moderate medium and fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and few fine roots; common very fine and few fine dendritic tubular pores; few faint patchy clay films on faces of peds; many silt and sand skeletans on faces of peds; 5 percent gravel; neutral (pH 6.8); clear wavy boundary. (3 to 8 inches thick)

Bt--15 to 21 inches; light brown (7.5YR 6/4) clay, brown (7.5YR 5/4) moist; strong coarse prismatic structure parting to strong coarse and medium angular blocky; hard, firm, moderately sticky and moderately plastic; common very fine and few fine roots; common very fine and few fine dendritic tubular pores; faint continuous and common distinct patchy clay films on faces of peds; 5 percent gravel; slightly alkaline (pH 7.4); clear wavy boundary. (6 to 20 inches thick)

Btk--21 to 37 inches; light brown (7.5YR 6/4) silty clay loam, strong brown (7.5YR 5/6) moist; strong medium prismatic structure parting to strong medium and fine angular blocky; hard, firm, moderately sticky and moderately plastic; few very fine roots; common very fine dendritic tubular pores; faint continuous and few distinct patchy clay films on faces of peds; 5 percent gravel; disseminated calcium carbonate and common medium and fine patchy soft masses and threads of calcium carbonate; slightly effervescent on faces of peds; slightly alkaline (pH 7.8); clear wavy boundary. (0 to 16 inches thick)

Bk--37 to 60 inches; light yellowish brown (10YR 6/4) clay loam, yellowish brown (10YR 5/4) moist; weak medium prismatic structure parting to moderate medium and fine subangular blocky; slightly hard, friable, moderately sticky and slightly plastic; few very fine roots; common very fine dendritic tubular pores; 10 percent gravel; disseminated calcium carbonate and common medium and fine patchy soft masses and threads of calcium carbonate; strongly effervescent; moderately alkaline (pH 8.4).

TYPE LOCATION: Beaverhead County, Montana; approximately 150 feet south and 2,100 feet west of the NE corner of sec. 25, T 4 S., R 16 W. Ajax Ranch topographic quadrangle, Latitude 45 degrees 27 minutes 56 seconds N. and Longitude 113 degrees 30 minutes 55 seconds W.

RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 35 to 40 degrees F., Cryic temperature regime
Mollic epipedon thickness - 9 to 15 inches
Depth to argillic horizon - 13 to 20 inches
Depth to secondary calcium carbonate accumulation - 26 to 50 inches
Depth to calcic horizon - 30 to 50 inches

Note: Some pedons may have a Bt/E horizon.

A horizons
Value: 4 or 5 dry; 2 or 3 moist
Chroma: 1 to 3; dry or moist
Texture: loam or silt loam
Clay content: 18 to 27 percent
Rock fragments: 0 to 25 percent--0 to 15 percent gravel, 0 to 15 percent cobbles
Reaction: pH 6.5 to 7.3

E/Bt horizon
Hue: 7.5YR or 10YR; dry or moist (E and Bt part)
Value:
E part - 7 or 8 dry; 5 or 6 moist
Bt part - 5 or 6 dry; 4 or 5 moist
Chroma:
E part - 1 to 3; dry or moist
Bt part - 3 or 4; dry or moist
Texture: loam, clay loam, or silt loam
Clay content: 20 to 30 percent
Rock fragments: 5 to 40 percent--5 to 30 percent gravel, 0 to 20 percent cobbles
Reaction: pH 6.2 to 7.3

Bt horizon
Hue: 7.5YR or 10YR; dry or moist
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 3 to 6; dry or moist
Texture: clay loam, clay or silty clay
Clay content: 35 to 45 percent
Rock fragments: 0 to 25 percent gravel
Reaction: pH 6.6 to 7.4

Btk horizon
Hue: 7.5YR or 10YR
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 4 or 6; dry or moist
Texture: clay loam, silty clay loam or clay
Clay content: 30 to 45 percent
Rock fragments: 0 to 25 percent gravel
Calcium carbonate equivalent: 1 to 5 percent
Reaction: pH 7.5 to 8.3

Bk horizon
Hue: 7.5YR or 10YR; dry or moist
Value: 6 to 8 dry; 5 to 7 moist
Chroma: 2 to 6; dry or moist
Texture: loam, clay loam, silt loam or silty clay loam
Clay content: 15 to 35 percent
Rock fragments: 10 to 40 percent--10 to 35 percent gravel, 0 to 5 percent cobbles
Calcium carbonate equivalent: 5 to 25 percent
Reaction: pH 7.6 to 8.6
Note: Some pedons may have sandy loam textures in the Bk horizon at depths greater than 100 cm.

COMPETING SERIES: There are no competing series.

GEOGRAPHIC SETTING:
Landform - stream terraces, fan remnants, alluvial fans and depressions
Elevation - 5,900 to 7,300 feet
Slope - 0 to 8 percent
Parent material - mixed alluvium
Climate - long, cold winters; cool, moist springs; short, cool summers
Mean annual precipitation - 14 to 19 inches
Mean annual air temperature - 34 to 40 degrees F.
Frost-free period - 30 to 70 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Mooseflat, Shewag and Wisdom soils. The Mooseflat soils are very poorly drained and are on floodplains and drainageways. Shewag soils are sandy-skeletal and are on outwash plains. Wisdom soils are fine-loamy over sandy or sandy-skeletal and are on outwash plains.

DRAINAGE AND PERMEABILITY: Well drained, slow permeability.

USE AND VEGETATION: Beaverslide soils are used for irrigated grass hay and irrigated pasture. The vegetation is mainly Garrison creeping foxtail, meadow foxtail, timothy, tufted hairgrass, and other miscellaneous sedges, rushes and forbs.

DISTRIBUTION AND EXTENT: Beaverslide soils are not extensive in the intermountain valleys of southwestern Montana. MLRA 44B.

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

SERIES ESTABLISHED: Beaverhead County, Montana, Big Hole Area, 2005.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - from 2 to 12 inches (A1 and A2 horizons);
Glossic horizon - from 12 to 15 inches (E/Bt horizon);
Argillic horizon - from 15 to 37 inches (Bt and Btk horizons)
Calcic horizon - from 37 to 60 inches (Bk horizon)
Horizons with redox concentrations - from 2 to 12 inches (A1 and A2 horizons)
Particle-size control section - from 15 to 35 inches (Bt and part of Btk horizons).

Beaverslide soils have a cryic temperature regime, an ustic moisture regime and an oxyaquic moisture subclass.

National Cooperative Soil Survey
U.S.A.