LOCATION YNOT               MT
Established Series
Rev. DRS-GFB-JAL
10/98

YNOT SERIES


The Ynot series consist of very deep, well drained soils formed in alluvium or eolian material. Ynot soils are on stream terraces, alluvial fans, sedimentary plains, and hills. Slopes are 0 to 15 percent. The mean annual precipitation is about 12 inches, and the mean annual temperature is about 43 degrees F.

TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, frigid Aridic Haplustolls

TYPICAL PEDON: Ynot sandy loam, in rangeland (colors are for dry soil unless otherwise stated).

A--0 to 6 inches; brown (10YR 5/3) sandy loam, very dark grayish brown (10YR 3/2) moist; moderate medium and fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine and common fine roots; many very fine tubular pores; neutral (pH 6.8); clear smooth boundary. (4 to 10 inches thick)

Bw1--6 to 13 inches; grayish brown (10YR 5/2) sandy loam, very dark grayish brown (10YR 3/2) moist; moderate coarse and medium subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; many very fine and few fine roots; many very fine and common fine tubular pores; neutral (pH 6.8) clear smooth boundary.

Bw2--13 to 18 inches; light yellow brown (2.5Y 6/4) sandy loam, olive brown (2.5Y 4/4) moist; weak medium subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; common very fine and few fine roots; many very fine and common fine tubular pores; neutral (pH 7.0); gradual smooth boundary. (Combined thickness of the Bw horizons is 10 to 21 inches.)

C--18 to 60 inches; light yellowish brown (2.5Y 6/4) sandy loam; light olive brown (2.5Y 5/4) moist; massive; slightly hard, very friable, nonsticky and nonplastic; few very fine roots; few very fine and common fine pores; neutral (pH 7.2).

TYPE LOCATION: Fallon County, Montana; 2,200 feet east and 2,500 feet south of the NW corner of sec. 35, T.1 N., R.58 E.

RANGE IN CHARACTERISTICS:

Soil temperature - 42 to 47 degrees F.

Moisture control section - between 12 and 35 inches; dry in some part for six tenths or more of the cumulative days per year when the soil temperature at a depth of 20 inches is higher than 41 degrees F.

Mollic epipedon thickness - 7 to 16 inches (includes part of the Bw horizon).

Control section - 10 to 18 percent clay.

Some soils are calcareous below a depth of 40 inches.

A horizon - Hue: 10YR or 2.5Y

Value: 2 or 3 moist

Chroma: 2 or 3

Clay content: 10 to 18 percent

Reaction: pH 6.1 to 7.3

Bw horizons - Hue: 10YR or 2.5Y

Value: 5, 6, or 7 dry; 3, 4, 5, or 6 moist

Chroma: 2, 3, or 4

Texture: sandy loam or fine sandy loam

Clay content: 10 to 18

Reaction: pH 6.1 to 7.3

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

Value: 5, 6, or 7 dry; 4, 5, or 6 moist

Chroma: 2, 3, or 4

Texture: sandy loam or fine sandy loam

Clay content: 10 to 18 percent

Reaction: pH 6.1 to 7.8

COMPETING SERIES:

Anaconda (MT) - have a calcic horizon.

Chinook (MT) - have secondary carbonate accumulation above a depth of 40 inches.

Cozberg (MT) - have secondary carbonate accumulation above a depth of 40 inches.

Lahood (MT) - has a lithic contact at 20 to 40 inches.

Pring (CO) - are extremely hard at a depth of 20 inches; formed in arkose materials that have a high percent of flat bearing surface.

Rhame (ND) - have secondary carbonate accumulation above a depth of 40 inches.

Tinytown (CO) - have hues redder than 10YR in the cambic horizon; have more than 15 percent coarse fragments in the control section.

GEOGRAPHIC SETTING:

Landform - stream terraces; alluvial fans; sedimentary plains; hills.

Elevation - 2,500 to 3,200 feet.

Slope- 0 to 15 percent.

Parent material - alluvium or eolian material.

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

Mean annual precipitation - 10 to 14 inches.

Mean annual temperature - 41 to 45 degrees F.

Frost-free period - 110 to 135 days.

DRAINAGE AND PERMEABILITY: Well drained; moderately rapid permeability.

USE AND VEGETATION: Ynot soils are used for range and nonirrigated crops. The native vegetation consists of needleandthread, prairie sandreed, bluebunch wheatgrass, little bluestem, forbs, and shrubs.

DISTRIBUTION AND EXTENT: Southeastern Montana. Ynot soils are not extensive.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado

SERIES ESTABLISHED: Fallon County, Montana, 1991.

REMARKS: Soil interpretations record: MT1269. Diagnostic horizons and features recognized in this pedon are: a mollic epipedon from 0 to 13inches (A, Bw1 horizons); a cambic horizon from 13 to 18 inches (Bw2 horizon); a particle-size control section from 10 to 40 inches (Bw1, Bw2, C horizons). Ynot soils have a frigid temperature regime and an ustic moisture regime bordering on aridic.


National Cooperative Soil Survey
U.S.A.