LOCATION LONESOME MTEstablished Series
TAXONOMIC CLASS: Sandy over loamy, mixed, superactive, calcareous, frigid Aridic Ustorthents
TYPICAL PEDON: Lonesome loamy fine sand, in cropland. (Colors are for dry soil unless otherwise noted)
A--0 to 5 inches; brown (10YR 5/3) loamy fine sand, brown (10YR 4/3) moist; single grain; loose, nonsticky and nonplastic; many very fine roots; neutral (pH 6.8); clear smooth boundary. (4 to 7 inches thick)
Bw--5 to 15 inches; brown (10YR 5/3) loamy fine sand, brown (10YR 4/3) moist; weak coarse subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine roots; neutral (pH 6.8); clear smooth boundary. (9 to 29 inches thick)
Bk1--15 to 30 inches; light yellowish brown (10YR 6/4) loamy fine sand, yellowish brown (10YR 5/4) moist; weak coarse subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine roots; few fine seams of lime; strongly effervescent; moderately alkaline (pH 8.4); clear smooth boundary. (0 to 16 inches thick)
2Bk2--30 to 51 inches; pale brown (10YR 6/3) clay loam, brown (10YR 5/3) moist; moderate fine and medium subangular blocky structure; hard, friable, slightly sticky and plastic; common very fine roots; common very fine pores; common fine masses and seams of lime; violently effervescent; strongly alkaline (pH 8.8); clear wavy boundary. (6 to 22 inches thick)
2Bk3--51 to 60 inches; light yellowish brown (10YR 6/4) clay loam, yellowish brown (10YR 5/4) moist; weak fine and medium subangular blocky structure; very hard, firm, very sticky and very plastic; few very fine roots; few very fine tubular pores; common fine masses of lime; violently effervescent; strongly alkaline (pH 8.8).
TYPE LOCATION: Hill County, Montana; 1,400 feet south and 1,400 feet west of the NE corner of sec. 11, T. 36 N., R. 14 E.
RANGE IN CHARACTERISTICS:
Soil temperature - 44 to 47 degrees F.
Moisture control section - between 12 and 35 inches; dry in all parts between four-tenths and five-tenths of the cumulative days per year when the soil temperature at a depth of 20 inches is 41 degrees F or higher.
Depth to 2Bk2 horizon - 20 to 40 inches, mainly 24 to 38 inches.
Ap horizon - Hue: 10YR or 2.5Y
Value: 4 or 5 dry, 3 or 4 moist
Chroma: 2, 3, or 4
Clay content: 5 to 15 percent
Rock fragments: 0 to 2 percent pebbles
Reaction: pH 6.6 to 7.8
Some pedons contain A2 horizons 3 to 6 inches thick which, when combined with the A horizon, meet all the requirements for a mollic epipedon except for organic matter content. The A2 horizon has a loamy fine sand, loamy sand, or fine sand texture.
Bw horizon - Hue: 10YR or 2.5Y
Value: 5 or 6 dry; 3 to 5 moist
Chroma: 3 or 4
Texture: loamy fine sand, loamy sand or fine sand
Clay content: 5 to 15 percent
Rock fragments: 0 to 2 percent
Reaction: pH 6.6 to 7.8
Bk1 horizon - Hue: 10YR or 2.5Y
Value: 5 or 6 dry; 3 to 5 moist
Chroma: 3 or 4
Texture: loamy fine sand, loamy sand or fine sand
Clay content: 5 to 15 percent
Rock fragments: 0 to 2 percent
Calcium carbonate equivalent: 5 to 15 percent
Reaction: pH 7.9 to 8.4
2Bk horizons - Hue: 10YR or 2.5Y
Value: 5 to 7 dry; 4 to 6 moist
Chroma: 2 to 4
Texture: clay loam, loam or silty clay loam (contains less than 50 percent fine or coarser sand)
Clay content: 20 to 35 percent
Rock fragments: 0 to 5 percent
Calcium carbonate equivalent: 5 to 15 percent
EC: 0 to 4 mmhos/cm
SAR: 0 to 13
Reaction: pH 7.9 to 9.0
Some pedons have a 2Bky horizon with 1 to 2 percent gypsum. Some pedons have thin lenses of fine sandy loam or loam textures between thicker layers of loam or clay loam.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING:
Landform - till plains; stream terraces; dunes.
Elevations - 2,700 to 3,500 feet.
Slopes- 0 to 8 percent.
Parent material - alluvium or eolian material over till, glaciofluvial or glaciolacustrine deposits.
Climate - long, cold winters; moist springs; hot, dry summers.
Mean annual precipitation - 10 to 14 inches, most of which falls during spring and early summer.
Mean annual air temperature - 42 to 45 degrees F.
Frost-free period - 105 to 125 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Chinook, Fortbenton, Lihen and Yetull soils.
DRAINAGE AND PERMEABILITY: Well drained; rapid permeability above the 2Bk2 horizon and slow in the 2Bk2 and below.
USE AND VEGETATION: Lonesome soils are used as nonirrigated cropland and rangeland. The potential plant community is prairie sandreed, Indian ricegrass, needleandthread and sand dropseed.
DISTRIBUTION AND EXTENT: Lonesome soils are of small extent in north-central Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Chouteau County, Montana 1992.
REMARKS: Soil interpretation record: MT1270. The diagnostic horizon and features recognized in this pedon are: an ochric epipedon from the surface to 5 inches, mixed (A horizon); and a contrasting particle-size control section.
ADDITIONAL DATA: Laboratory data S91MT-041-4, S86MT-015-539.