LOCATION GROFF MT
Established Series
Rev. EMR/JMS/RJS
07/2013
GROFF SERIES
The Groff series consists of very deep, somewhat poorly drained soils that formed in alluvium from mixed sources. These soils are on flood plains or in drainageways. Slopes range from 0 to 4 percent. The mean annual precipitation is 330 mm, and the mean annual temperature is 6 degrees C.
TAXONOMIC CLASS: Coarse-loamy over sandy or sandy-skeletal, mixed, superactive, frigid Aquic Cumulic Haplustolls
TYPICAL PEDON: Groff loam, in rangeland on a 1 percent slope at 1,054 meters elevation (colors are for dry soil unless otherwise stated).
A1--0 to 46 cm; dark grayish brown (10YR 4/2) loam, very dark brown (10YR 2/2) moist; moderate medium granular structure; soft, friable, slightly sticky and nonplastic; many fine and medium roots; many very fine and fine irregular and tubular pores; 5 percent gravel; neutral (pH 6.8); gradual smooth boundary.
A2--46 to 71 cm; dark gray (10YR 4/1) loam, black (10YR 2/1) moist; weak fine subangluar blocky structure; soft, very friable, nonsticky and nonplastic; many fine and medium roots; many fine interstitial pores; 5 percent gravel; neutral (pH 7.2); clear smooth boundary. (combined thickness of the A horizons is 50 to 71 cm)
C1--71 to 84 cm; light brownish gray (10YR 6/2) gravelly loamy coarse sand, dark grayish brown (10YR 4/2) moist; single grain; loose, nonsticky and nonplastic; few fine roots; common fine interstitial pores; 5 percent medium distinct grayish brown (2.5Y 5/2) moist redox depletions; 25 percent gravel; neutral (pH 7.2); gradual smooth boundary.
C2--84 to 152 cm; light brownish gray (10YR 6/2) very gravelly coarse sand, dark grayish brown (10YR 4/2) moist; single grain; loose, nonsticky and nonplastic; common fine interstitial pores; 10 percent coarse prominent yellowish brown (10YR 5/6) moist redox concentrations and 5 percent coarse distinct grayish brown (2.5Y 5/2) moist redox depletions; 40 percent gravel; neutral (pH 6.8)
TYPE LOCATION: Victor topographic quadrangle, Ravalli County, Montana; 660 meters north and 570 meters west of the SE corner of section 25, T. 8 N., R. 21 W. UTM Zone 11: 717987e, 5144625n, NAD 83.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 5 to 8 degrees C
Moisture control section - 20 to 60 cm
Depth to seasonal high water table - 60 to 100 cm for extended periods during portions of the late spring and early summer
Mollic epipedon thickness - 50 to 71 cm
Depth to sandy-skeletal material - 50 to 71 cm
A1 horizon
Value: 4 or 5 dry; 2 or 3 moist
Chroma: 1 or 2 dry or moist
Texture: loam or silt loam
Clay content: 14 to 20 percent
Rock fragments: 0 to 15 percent--0 to 10 percent gravel, 0 to 5 percent cobbles
Reaction: pH 6.0 to 7.2
A2 horizon
Value: 4 or 5 dry; 2 or 3 moist
Chroma: 1 or 2 dry or moist
Texture: loam or silt loam
Clay content: 10 to 18 percent
Rock fragments: 0 to 15 percent--0 to 10 percent gravel, 0 to 5 percent cobbles
Reaction: pH 6.6 to 7.8
C1 horizon
Value: 5 or 6 dry; 3 or 4 moist
Chroma: 1 or 2 dry or moist
Texture: loamy coarse sand, coarse sand, loamy sand, or sand
Clay content: 0 to 15 percent
Rock fragments: 15 to 60 percent--15 to 60 percent gravel, 0 to 15 percent cobbles
Reaction: pH 6.4 to 7.8
C2 horizon
Value: 5 or 6 dry; 3 or 4 moist
Chroma: 1 or 2 dry or moist
Texture: coarse sand, loamy coarse sand, or sand
Clay content: 0 to 10 percent
Rock fragments: 35 to 85 percent--15 to 70 percent gravel, 0 to 35 percent cobbles
Reaction: pH 6.0 to 7.3
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING:
Landform - flood plains and drainageways
Slopes - 0 to 4 percent
Elevation - 970 to 1,440 meters
Parent material - alluvium derived from mixed sources
Climate - long, cold winters; moist springs; warm summers
Mean annual precipitation - 305 to 432 millimeters
Mean annual air temperature - 4 to 7 degrees C
Frost-free period - 85 to 115 days
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND PERMEABILITY: somewhat poorly drained; moderate permeability with rapid and very rapid permeability below 71 cm.
USE AND VEGETATION: These soils are used primarily for pasture, rangeland, and wildlife habitat. Vegetation is chiefly mixed grasses, small grains, and minor acreages of other specialty crops.
DISTRIBUTION AND EXTENT: The Groff series is of small extent in the intermountain valleys of southwestern Montana. MLRA 44A.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana.
SERIES ESTABLISHED: Bitterroot Valley Area, Montana, 2013; proposed in Ravalli County, Montana, 2007.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - from 0 to 71 cm (A1 and A2 horizons)
Redoximorphic features - from 71 to 152 cm (C1 and C2 horizons)
Particle-size control section - from 25 to 100 cm (part of the A1, A2, C1, and part of the C2 horizons)
Groff soils have a frigid temperature regime, an ustic moisture regime, and an aquic moisture subclass.
National Cooperative Soil Survey
U.S.A.