LOCATION LINNET             MT
Established Series
Rev. RER
10/98

LINNET SERIES


The Linnet series consists of very deep, well drained soils that formed in clayey alluvium and glaciolacustrine deposits. These soils are on lake plains, stream terraces, alluvial fans, drainageways, and till plains. Slopes are 0 to 10 percent. Mean annual precipitation is about 12 inches, and mean annual temperature is about 43 degrees F. The frost-free period is about 120 days.

TAXONOMIC CLASS: Fine, smectitic, frigid Torrertic Argiustolls

TYPICAL PEDON: Linnet silty clay loam, cropland (colors are for dry soil unless otherwise noted).

Ap--0 to 6 inches; grayish brown (2.5Y 5/2) silty clay loam, very dark grayish brown (2.5Y 3/2) moist; strong fine and very fine granular structure; very hard, friable, sticky and plastic; many fine and very fine roots; many fine pores; common unstained sand grains; neutral (pH 7.2); abrupt wavy boundary. (5 to 8 inches thick)

Bt--6 to 15 inches; dark brown (10YR 4/3) silty clay, very dark grayish brown (10YR 3/2) moist; strong medium prismatic structure parting to strong fine and very fine angular blocky; extremely hard, firm, sticky and very plastic; many fine and very fine roots with some along faces of peds; many fine and very fine and few medium tubular pores; continuous faint clay films on faces of peds; common pressure faces 1 to 3/4 inch wide cracks; neutral (pH 7.4); clear wavy boundary. (6 to 12 inches thick)

Btk--15 to 30 inches; light yellowish brown (2.5Y 6/3) silty clay, olive brown (2.5Y 4/3) moist; strong medium and coarse prismatic structure parting to strong fine and medium blocky, many fine and very fine roots; many fine and very fine pores, few fine medium pores; few faint grayish brown (2.5Y 5/2) clay films on faces of peds; 5 percent pebbles; continuous faint lime casts on underside of pebbles; few, fine masses of segregated lime; strongly effervescent; moderately alkaline (pH 8.4); clear wavy boundary. (10 to 20 inches thick)

Bk1--30 to 42 inches; light brownish gray (2.5Y 6/2) silty clay, dark grayish brown (2.5Y 4/2) moist; weak coarse prismatic structure parting to weak medium and coarse blocky; very hard, friable, sticky and plastic; common fine and very fine roots; many fine and very fine pores, few fine and medium pores; few fine masses of segregated lime; strongly effervescent; strongly alkaline (pH 9.0); clear wavy boundary. (10 to 20 inches thick)

BCy--42 to 66 inches; grayish brown and light brownish gray (2.5Y 5/2 and 6/2) clay loam, dark grayish brown (2.5Y 4/2) moist; weak thick and very thick platy structure parting to weak fine and medium blocky; extremely hard, firm, sticky and plastic; few fine pores; few fine lignite chips; 5 percent pebbles; slightly effervescent; common fine nests and seams of gypsum; strongly alkaline (pH 8.8).

TYPE LOCATION: Cascade County, Montana; 310 feet north and 525 feet east of SW corner of sec. 15, T. 22 N., R. 4 E.

RANGE IN CHARACTERISTICS:

Soil temperature - 41 to 47 degrees F.

Soil moisture control section - between 4 and 12 inches.

Mollic epipedon - 7 to 16 inches thick.

Surface cracks - 1 to 2 inches wide.

Depth to Btk or Bk horizon - 11 to 20 inches.

A horizon - Hue: 10YR or 2.5Y

Chroma: 2 or 3

Texture: clay loam, silty clay loam, clay, or silty clay

Clay content: 30 to 45 percent

Rock fragments: 0 to 10 percent pebbles

Reaction: pH 6.1 to 7.3

Bt horizon - Hue: 10YR or 2.5Y

Value: 5 or 6 dry; 4 or 5 moist

Chroma: 2, 3, or 4

Clay content: 45 to 60 percent

Texture: clay loam, silty clay loam, clay, or silty clay

Rock fragments: 0 to 10 percent pebbles

Reaction: pH 6.6 to 7.8

Btk and Bk horizons - Hue: 10YR or 2.5Y

Value: 5 or 6 dry; 4 or 5 moist

Chroma: 2 or 3

Texture: clay, silty clay, or silty clay loam

Clay content: 35 to 50 percent

Rock fragments: 0 to 15 percent pebbles

Calcium carbonate equivalent: 5 to 15 percent

SAR: 0 to 13

Reaction: pH 7.4 to 9.0

BCy horizon - Hue: 10YR, 2.5Y, or 5Y

Value: 5 or 6 dry, 4 or 5 moist

Chroma: 2 or 3

Texture: clay, silty clay, clay loam, or silty clay loam

Clay content: 35 to 50 percent

Rock fragments: 0 to 15 percent pebbles

Gypsum: 2 to 5 percent

SAR: 2 to 13

Reaction: pH 7.9 to 9.0

A C horizon and stratification of silty clay loam, silty clay, and clay occurs below 35 inches in some pedons.

COMPETING SERIES:

Cerro (CO) - are stony below a depth of 26 inches and are mainly stony above 26 inches; receive 15 to 25 inches of precipitation; are at elevations greater than 6,600 feet.

Dutton (MT) - have a paralithic contact above a depth of 40 inches.

Mondamin (SD) - have mottles at 24 inches and deeper; have tongues of surface materials extending to depths greater than 40 inches; have precipitation greater than 14 inches.

GEOGRAPHIC SETTING:

Landform - stream terraces, alluvial fans, lake plains, drainageways, and till plains.

Elevation - 2,200 to 4,000 feet.

Slope- 0 to 10 percent.

Parent material - alluvium and glaciolacustrine deposits.

Climate - long, cold winters; cool, moist springs; short, warm, dry summers.

Mean annual precipitation - 10 to 14 inches.

Mean annual air temperature - 42 to 45 degrees F.

Frost-free period - 105 to 135 days.

DRAINAGE AND PERMEABILITY: Well-drained; slow permeability.

USE AND VEGETATION: Linnet soils are used mainly for nonirrigated cropland and rangeland. Potential native vegetation is mainly western wheatgrass, bluebunch wheatgrass, green needlegrass, Sandberg bluegrass, and forbs.

DISTRIBUTION AND EXTENT: Linnet soils are extensive on glaciated plains and lacustrine terraces in Montana.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota

SERIES ESTABLISHED: Cascade County, Montana, 1969.

REMARKS: Soil interpretation record: MT0110, MT0843. Linnet soils were formerly classified as Brown soils. Diagnostic horizons and features recognized in this pedon are: a mollic epipedon from the soil surface to 15 inches (Ap, Bt horizons); and argillic horizon from 6 to 30 inches that is also the particle-size control section (Bt, Btk horizons); accumulations of calcium carbonates from 15 to 42 inches (Btk, Bk horizons). Linnet soils have a frigid temperature regime and an ustic moisture regime that borders on aridic.

ADDITIONAL DATA: Laboratory sample S68MT-013-5.


National Cooperative Soil Survey
U.S.A.