Soil Survey of Sweet Grass County Area, Montana - Soil Data Mart

24 Soil Survey
few very fine and fine roots; few very fine and fine
crystals of gypsum and other salts; few fine
threads of lime; disseminated lime; slightly
effervescent; strongly alkaline (pH 8.5).
Range in Characteristics
Soil temperature: 42 to 47 degrees F (60 to
68 degrees F in summer)
Moisture control section: Between 4 and 12 inches
Depth to the Btknyz horizon: 6 to 20 inches
E horizon
Hue: 2.5Y, 10YR, or 7.5YR
Value: 6 or 7 dry; 3 to 5 moist
Chroma: 1 to 3
Texture (less than 2 mm): Loam, silt loam, or fine
sandy loam (Where mixed with the Bt horizon,
textures are mainly silty clay loam, clay loam,
silty clay, clay, silt loam, or sandy clay loam.)
Clay content: 15 to 55 percent
Content of rock fragments: 0 to 35 percent—0 to
5 percent cobbles; 0 to 30 percent gravel
Electrical conductivity: 4 to 8 mmhos/cm
Reaction: pH 6.6 to 8.4
Btn horizons
Hue: 2.5Y, 7.5YR, or 10YR
Value: 4 to 6 dry; 4 or 5 moist
Chroma: 1 to 3
Texture (less than 2 mm): Silty clay, clay, or clay
loam
Clay content: 35 to 60 percent
Structure: Moderate or strong columnar or
prismatic
Consistence: Very hard or extremely hard when
dry
Content of rock fragments: 0 to 15 percent gravel
Electrical conductivity: 8 to 16 mmhos/cm
Sodium adsorption ratio: 18 to 50
Reaction: pH 6.6 to 9.6
Btknyz horizon
Hue: 2.5Y, 10YR, or 7.5YR
Value: 4 to 6 dry; 4 or 5 moist
Chroma: 2 or 3
Texture (less than 2 mm): Clay loam, clay, or silty
clay
Clay content: 35 to 50 percent
Content of rock fragments: 0 to 20 percent gravel
Calcium carbonate equivalent: 5 to 15 percent
Electrical conductivity: 8 to 32 mmhos/cm
Sodium adsorption ratio: 18 to 50
Gypsum content: 1 to 5 percent
Reaction: pH 7.9 to 9.6
Bknyz and Bkyz horizons
Hue: 2.5Y, 10YR, or 7.5YR
Value: 5 to 7 dry; 4 to 6 moist
Chroma: 2 to 4
Texture (less than 2 mm): Clay loam, sandy clay
loam, silty clay, clay, or silty clay loam
Clay content: 27 to 45 percent
Content of rock fragments: 0 to 20 percent gravel
Calcium carbonate equivalent: 5 to 15 percent
Electrical conductivity: 8 to 32 mmhos/cm
Sodium adsorption ratio: 18 to 50
Gypsum content: 1 to 5 percent
Reaction: pH 7.9 to 9.6
Adel Series
Depth class: Very deep (greater than 60 inches)
Drainage class: Well drained
Permeability: Moderate (0.6 to 2.0 inches/hour)
Landform: Swale on fan, drainageway on mountain,
fan on mountain, and swale on mountain
Parent material: Loamy alluvium or colluvium
Slope range: 2 to 45 percent
Elevation range: 5,500 to 7,500 feet
Mean annual precipitation: 20 to 25 inches
Mean annual air temperature: 35 to 44 degrees F
Frost-free period: 50 to 70 days
Taxonomic Class: Fine-loamy, mixed, superactive
Pachic Haplocryolls
Typical Pedon
Adel loam, in an area of Adel-Timberlin complex, 8 to
35 percent slopes, in an area of deciduous forest,
400 feet south and 2,100 feet west of the northeast
corner of sec. 13, T. 3 S., R. 13 E.; USGS Squaw
Peak topographic quadrangle (lat. 45 o 34'53" N.; long.
110 o 03'41" W.)
A1—0 to 12 inches; very dark gray (10YR 3/1) loam,
black (10YR 2/1) moist; strong fine granular
structure; slightly hard, friable, slightly sticky,
slightly plastic; few medium and coarse and many
very fine and fine roots; many very fine and fine
pores; 5 percent gravel; neutral (pH 6.6); clear
smooth boundary.
A2—12 to 23 inches; very dark grayish brown (10YR
3/2) loam, very dark brown (10YR 2/2) moist;
moderate fine granular structure; soft, friable,
slightly sticky, slightly plastic; few coarse and
common fine and medium roots; many very fine
and fine pores; 5 percent gravel; slightly acid
(pH 6.4); clear smooth boundary.