LOCATION VARNEY MT
Established Series
Rev. JB-JJU-EMM
04/2014
VARNEY SERIES
The Varney series consists of very deep, well drained soils that formed in alluvium, slope alluvium or slide deposits. These soils are on alluvial fans, fan remnants, stream terraces, strath terraces, escarpments, knolls, hills and landslides. Slopes are 0 to 60 percent. Mean annual precipitation is about 13 inches, and mean annual air temperature is about 40 degrees F.
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Calcidic Argiustolls
TYPICAL PEDON: Varney clay loam, in cropland (colors are for dry soil unless otherwise noted).
Ap--0 to 5 inches; grayish brown (10YR 5/2) clay loam, very dark grayish brown (10YR 3/2) moist; moderate very fine and fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine roots; many very fine and fine interstitial pores; 5 percent gravel; neutral (pH 6.6); clear smooth boundary. (3 to 9 inches thick)
Bt--5 to 16 inches; brown (10YR 5/3) clay loam, brown (10YR 4/3) moist; moderate fine and medium subangular blocky structure; hard, friable, moderately sticky and moderately plastic; many very fine and fine roots; common fine tubular pores; continuous, faint clay films on faces of peds; 10 percent gravel; neutral (pH 7.3); clear irregular boundary. (5 to 15 inches thick)
Bk1--16 to 28 inches; light gray (10YR 7/2) gravelly sandy clay loam, pale brown (10YR 6/3) moist; weak coarse prismatic structure; slightly hard, friable, slightly sticky and nonplastic; common very fine and fine roots; common very fine and fine pores; 15 percent gravel and 5 percent cobbles; common fine masses of calcium carbonate; violently effervescent; moderately alkaline (pH 7.9); gradual smooth boundary. (5 to 25 inches thick)
Bk2--28 to 48 inches; very pale brown (10YR 7/3) gravelly sandy loam, pale brown (10YR 6/3) moist; weak, coarse, prismatic structure; soft, friable, slightly sticky and nonplastic; few fine roots; few fine pores; 15 percent gravel and 5 percent cobbles; few fine masses of calcium carbonate, and finely disseminated calcium carbonate; strongly effervescent; moderately alkaline (pH 7.9); clear smooth boundary. (5 to 25 inches thick)
BC--48 to 60 inches; light brown (7.5YR 6/4) stratified gravelly sandy loam and gravelly loamy sand, brown (7.5YR 5/4) moist; massive; slightly hard, friable, slightly sticky and nonplastic; few fine roots; few fine pores; 20 percent gravel and 5 percent cobbles; slightly effervescent; moderately alkaline (pH 8.4).
TYPE LOCATION: Madison County, Montana; 2,400 feet north and 2,300 feet west of the southeast corner of Sec. 32, T. 2S, R. 1W.
RANGE IN CHARACTERISTICS:
Soil temperature - 40 to 47 degrees F.
Mollic epipedon thickness - 7 to 16 inches and may include part of the argillic horizon
Depth to calcic horizon - 9 to 20 inches (mainly 12 to 17 inches)
Note: Some pedons may have a Btk horizon.
Ap horizon
Hue: 10YR or 2.5Y; dry or moist
Value: 4 or 5 dry; 2 or 3 moist
Chroma: 2 or 3; dry or moist
Texture: clay loam, loam or sandy clay loam
Clay content: 18 to 35 percent
Rock fragments: 0 to 50 percent--0 to 30 percent gravel, 0 to 20 percent cobbles
Electrical conductivity: 0 to 2 mmhos/cm
Reaction: pH 6.6 to 7.8
Bt horizon
Hue: 10YR or 2.5Y; dry or moist
Value: 4 to 6 dry; 3 to 5 moist
Chroma: 2 to 4; dry or moist
Texture: clay loam, loam or sandy clay loam
Clay content: 25 to 35 percent
Rock fragments: 0 to 35 percent--0 to 30 percent gravel, 0 to 15 percent cobbles
Electrical conductivity: 0 to 2 mmhos/cm
Reaction: pH 6.6 to 7.8
Bk1 horizon
Hue: 10YR or 2.5Y; dry or moist
Value: 5 to 8 dry; 4 to 7 moist
Chroma: 2 to 4; dry or moist
Texture: sandy loam, loam, clay loam or sandy clay loam
Clay content: 10 to 30 percent
Rock fragments: 0 to 35 percent--0 to 30 percent gravel, 0 to 5 percent cobbles
Calcium carbonate equivalent: 15 to 30 percent
Electrical conductivity: 0 to 2 mmhos/cm
Reaction: pH 7.4 to 8.4
Bk2 horizon
Hue: 10YR or 2.5Y; dry or moist
Value: 6 to 8 dry; 4 to 7 moist
Chroma: 3 or 4; dry or moist
Texture: sandy loam, loam or sandy clay loam
Clay content: 10 to 30 percent
Rock fragments: 0 to 35 percent--0 to 30 percent gravel, 0 to 5 percent cobbles
Calcium carbonate equivalent: 5 to 30 percent
Electrical conductivity: 0 to 2 mmhos/cm
Reaction: pH 7.4 to 8.4
BC horizon
Hue: 2.5Y, 10YR or 7.5YR; dry or moist
Value: 5 to 7 dry; 4 to 6 moist
Chroma: 2 to 4; dry or moist
Texture: stratified loamy sand, loam, sandy loam, sandy clay loam or clay loam
Clay content: 5 to 25 percent
Rock fragments: 5 to 35 percent--5 to 35 percent gravel, 0 to 5 percent cobbles
Electrical conductivity: 0 to 2 mmhos/cm
Calcium carbonate equivalent: 5 to 25 percent
Reaction: pH 7.4 to 8.4
COMPETING SERIES:
Cortyzack (CO) - receive 15 to 20 inches of precipitation
Eldgin (UT) - have a lithologic discontinuity
Emlin (CO) - do not have a stratified layer below a depth of 40 inches
Fortlogan (MT) - are deep to a paralithic contact
Hysoop (MT) - do not have a stratified layer below a depth of 40 inches
Morval (NM) - have a lithologic discontinuity
Notter (UT) - peak precipitation occurs in the summer and fall
Nuley (MT) - are deep to a lithic contact
Thunderhead (MT) - are moderately deep to a paralithic and/or lithic contact
Villa grove (CO) - have an exchangeable sodium percent of 5 to 20 in the argillic horizon
GEOGRAPHIC SETTING:
Landform - alluvial fans, fan remnants, stream terraces, strath terraces, escarpments, knolls, hills and landslides
Elevation - 2,500 to 6,500 feet
Slope - 0 to 60 percent
Parent material - alluvium, slope alluvium or slide deposits
Climate - long, cold winters; moist springs; warm summers
Mean annual precipitation - 10 to 14 inches
Mean annual temperature - 38 to 45 degrees F.
Frost-free season - 70 to 130 days
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability.
USE AND VEGETATION: Varney soils are mainly used for irrigated crops, dryland crops, and as rangeland. The potential native vegetation is mainly bluebunch wheatgrass, western wheatgrass, needleandthread, and green needlegrass.
DISTRIBUTION AND EXTENT: Varney soils are extensive in the intermountain valleys in southwestern Montana. MLRAs - 44B, 46, 58A.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana.
SERIES ESTABLISHED: Madison County Area, Montana, 1983; proposed in Madison County Area, Montana, 1977.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - from 0 to 7 inches when mixed (Ap,part of Bt horizons)
Argillic horizon - from 5 to 16 inches (Bt horizon)
Calcic horizon - from 16 to 48 inches (Bk1, Bk2 horizons)
Particle-size control section - from 5 to 16 inches (Bt horizon)
Varney soils have a frigid temperature regime and an ustic moisture regime bordering on aridic.
ADDITIONAL DATA: Soil interpretations records - MT0374, MT0670.
National Cooperative Soil Survey
U.S.A.