LOCATION GIRD MTEstablished Series
TAXONOMIC CLASS: Coarse-silty, mixed, superactive, frigid Calcic Haploxerolls
TYPICAL PEDON: Gird silt loam, in cropland (colors are for dry soil unless otherwise noted).
Ap--0 to 10 inches; grayish brown (10YR 5/2) silt loam, very dark brown (10YR 2/2) moist; weak fine granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine and fine roots; common very fine pores; neutral (pH 6.6); abrupt smooth boundary. (8 to 12 inches thick)
Bw--10 to 17 inches; brown (10YR 5/3) silt loam, dark brown (10YR 4/3) moist; moderate medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine and fine roots; common very fine pores; neutral (pH 6.8); clear smooth boundary. (4 to 17 inches thick)
Bk1--17 to 32 inches; pale brown (10YR 6/3) silt loam, brown (10YR 5/3) moist; weak coarse subangular blocky structure; soft, very friable, nonsticky and nonplastic; few very fine and fine roots; common very fine pores; disseminated lime; strongly effervescent; slightly alkaline (pH 7.8); gradual wavy boundary. (12 to 24 inches thick)
Bk2--32 to 60 inches; light gray (10YR 7/2) silt loam, pale brown (10YR 6/3) moist; massive; soft, very friable, nonsticky and nonplastic; few very fine roots; few very fine pores; disseminated lime, common fine masses of lime; strongly effervescent; moderately alkaline (pH 8.4).
TYPE LOCATION: Lake County, Montana; 300 feet east and 150 feet north of the SW corner of sec. 30, T. 21 N., R. 19 W.
RANGE IN CHARACTERISTICS:
Soil temperature - 42 to 47 degrees F.
Moisture control section - between 4 and 12 inches.
Mollic epipedon thickness - 10 to 17 inches.
Depth to Bk horizon: 12 to 21 inches.
Some pedons have a BC or C horizon between 40 and 60 inches.
Ap horizon - Value: 4 or 5 dry; 2 or 3 moist
Chroma: 2 or 3
Clay content: 10 to 18 percent
Reaction: pH 6.6 to 7.3
Bw horizon - Value: 4 or 5 dry; 3 or 4 moist
Clay content: 10 to 18 percent
Reaction: pH 6.6 to 7.8
All or part of this horizon may have mollic colors.
Bk1 horizon - Hue: 10YR, 7.5YR
Value: 6 or 7 dry; 4 or 5 moist
Chroma: 2 or 3
Clay content: 10 to 18 percent
Calcium carbonate equivalent: 5 to 10 percent
Reaction: pH 7.4 to 8.4
Bk2 horizon - Hue: 10YR, 7.5YR
Value: 6 or 7 dry; 4, 5, or 6 moist
Chroma: 2, 3 or 4
Texture: silt loam or very fine sandy loam
Clay content: 10 to 18 percent
Calcium carbonate equivalent: 3 to 10 percent
Reaction: pH 7.4 to 8.4
COMPETING SERIES:
Rexberg (ID) - have clay films in the Bw1, cicada knotovinas in the Bk horizons, and more than 15 percent calcium carbonate equivalent in the Bk horizons.
Ririe (ID) - have an AB transition horizon, dense rounded nodules in the Bk2 horizon, and a calcium carbonate equivalent of more than 15 percent in the Bk horizon.
GEOGRAPHIC SETTING:
Landform - dissected alluvial fans, stream terraces, and till plains.
Elevation - 2,400 to 3,500 feet.
Slope- 0 to 45 percent.
Parent material - glaciofluvial deposits or alluvium.
Climate - cold winters; moist springs and falls; warm, dry summers.
Mean annual precipitation - 14 to 19 inches.
Mean annual temperature - 40 to 45 degrees F.
Frost-free period - 105 to 125 days.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability.
USE AND VEGETATION: Gird soils are used for irrigated and dryland crops.
DISTRIBUTION AND EXTENT: Gird soils are moderately extensive in intermountain valleys in western Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Ravalli County (Bitterroot Valley Area), Montana, 1952. Classification changed from typic to calcic for Lake County, Montana final correlation, 1991.
REMARKS: Soil Interpretation Records: MT0661, MT0835, MT7048. Diagnostic horizons and features recognized in this pedon are: a mollic epipedon from the soil surface to 10 inches (Ap horizon); a cambic horizon from 10 to 17 inches (Bw horizon); a particle-size control section from 10 to 40 inches (Bw, Bk1, Bk2 horizons). Gird soils have a frigid temperature regime and a xeric moisture regime.
Additional Data: Reference pedon S65MT-81-2