LOCATION BELTON MTEstablished Series
TAXONOMIC CLASS: Fine, illitic, frigid Typic Natrixerolls
TYPICAL PEDON: Belton silt loam, in cropland (colors are for dry soil unless otherwise noted).
Ap--0 to 8 inches; grayish brown (10YR 5/2) silt loam, very dark grayish brown (10YR 3/2) moist; moderate medium subangular structure; soft, very friable, slightly sticky and slightly plastic; many fine and medium roots; common very fine tubular pores; neutral (pH 7.2); abrupt smooth boundary. (7 to 11 inches thick)
Bt/E--8 to 10 inches; B part (70 percent) pale brown (10YR 6/3) silty clay loam, brown (10YR 5/3) moist; E part (30 percent) that interfingers into B part--very pale brown (10 YR 7/3) silt loam, dark grayish brown (10YR 5/2) moist; moderate coarse subangular blocky structure parting to moderate fine subangular blocky; slightly hard, friable, sticky and plastic; common medium and many fine roots; common medium and many very fine tubular pores; common distinct clay films on faces of peds; mildly alkaline (pH 7.8); abrupt smooth boundary. (0 to 5 inches thick)
Btn--10 to 19 inches; very pale brown (10YR 7/3) silty clay, brown (10YR 5/3) moist; strong medium prismatic structure parting to moderate medium angular blocky; hard, firm, very sticky and very plastic; few medium roots, common fine and many very fine roots; common very fine and few fine tubular pores; common distinct continuous dark brown (10YR 4/3) clay films on faces of peds and in pores; common distinct continuous very dark gray (10YR 3/1) organic films on faces of peds; strongly alkaline (pH 9.0); clear smooth boundary. (4 to 15 inches thick)
Bkn--19 to 29 inches; light gray (10YR 7/2) silty clay loam, pale brown (10YR 6/3) moist; weak coarse prismatic structure parting to moderate fine and medium platy; hard, firm, sticky and plastic; few fine and common very fine roots; common very fine tubular pores; disseminated lime and few faint masses of lime; violently effervescent; strongly alkaline (pH 8.6); clear wavy boundary. (5 to 12 inches thick)
C1--29 to 39 inches; white (10YR 8/2) silty clay loam, brown (10YR 5/3) moist; massive; fine stratification; common 1/4- to 2-inch thick varves; slightly hard, friable, slightly sticky and slightly plastic; few very fine roots; few very fine tubular pores; disseminated lime, strongly effervescent; moderately alkaline (pH 8.4); clear smooth boundary. (8 to 12 inches thick)
C2--39 to 60 inches; white (10YR 8/2) silt loam, pale brown (10YR 6/3) moist; massive; fine stratification; few 1/4- to 2-inch thick varves; slightly hard, friable, slightly sticky and slightly plastic; few very fine roots; few very fine tubular pores; disseminated lime, strongly effervescent; moderately alkaline (pH 8.2).
TYPE LOCATION: Lake County, Montana; 1,600 feet east and 50 feet north of the SW corner of sec. 24, T. 22 N., R. 21 W.
RANGE IN CHARACTERISTICS:
Soil temperature - 44 to 47 degrees F.
Moisture control section - between 4 and 12 inches; dry summers from late June through early August.
Mollic epipedon thickness - 7 to 12 inches.
Control section - 35 to 60 percent clay.
Depth to Bk horizon - 13 to 25 inches.
Ap horizon - Value: 4 or 5 dry, 2 or 3 moist
Chroma: 2 or 3
Texture: fine sandy loam, silt loam or loam
Clay content: 8 to 27 percent
Rock fragments: 0 to 15 percent--0 to 5 percent cobbles, 0 to 10 percent pebbles
Reaction: pH 6.1 to 7.3
Some pedons have A1 horizons.
Bt/E horizon - Hue: 10YR or 2.5Y
Value: B part 5, 6, or 7, E part 7 or 8 dry; B part 4 or 5, E part 5 or 6 moist
Chroma: B part 2 or 3, E part 2 or 3
Texture: B part silty clay loam or silty clay; E part silt loam or loam; mixed, silty clay loam.
Clay content: B part 35 to 45 percent; E part 18 to 27 percent; mixed 27 to 40 percent
Rock fragments: 0 to 15 percent--0 to 5 percent cobbles, 0 to 10 percent pebbles
SAR: 5 to 10
Reaction: pH 6.6 to 7.8
Btn horizon - Hue: 10YR, 2.5Y
Value: 6 or 7 dry; 4 or 5 moist
Chroma: 2 or 3
Texture: silty clay, clay, or silty clay loam
Clay content: 35 to 60 percent
Rock fragments: 0 to 15 percent--0 to 5 percent cobbles, 0 to 10 percent pebbles
EC: 2 to 4 mmhos/cm
SAR: 13 to 40 percent
Reaction: pH 8.5 to 9.0
Bkn horizon - Hue: 10YR or 2.5Y
Value: 6 or 7 dry; 5 or 6 moist
Chroma: 2 or 3
Texture: silty clay or silty clay loam
Clay content: 30 to 55 percent
Rock fragments: 0 to 15 percent--0 to 5 percent cobbles, 0 to 10 percent pebbles
Calcium carbonate equivalent: 10 to 15 percent
EC: 2 to 4 mmhos/cm
SAR: 13 to 30 percent
Reaction: pH 8.5 to 9.0
C1 & C2 horizons - Hue: 10YR or 2.5Y
Value: 6, 7 or 8 dry; 5 or 6 moist
Chroma: 2 or 3
Texture: silty clay, silty clay loam or silt loam
Clay content: 20 to 55 percent
Rock fragments: 0 to 15 percent--0 to 5 percent cobbles, 0 to 10 percent pebbles
Calcium carbonate equivalent: 5 to 10 percent
EC: 2 to 4 mmhos/cm
SAR: 10 to 30 percent
Reaction: pH 7.9 to 9.0
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING:
Landform - moraines, dissected lake plains, dissected alluvial fans, escarpments, and stream terraces.
Elevation - 2,400 to 3,500 feet.
Slope- 0 to 35 percent.
Parent material - clayey till or glaciolacustrine deposits.
Climate - long, cold winters; moist falls and springs; and warm, dry summers.
Mean annual precipitation - 12 to 19 inches, most of which falls as rain or snow in late fall through late spring.
Mean annual temperature - 42 to 45 degrees F.
Frost-free period - 105 to 135 days.
DRAINAGE AND PERMEABILITY: Well drained; slow permeability.
USE AND VEGETATION: Belton soils are used for irrigated and nonirrigated crops, and pastureland. Principal crops are wheat, barley, and alfalfa. The potential native vegetation is rough fescue, bluebunch wheatgrass, Idaho fescue, and basin wildrye.
DISTRIBUTION AND EXTENT: Belton soils are of moderate extent in the mountain valleys of northwestern Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana.
SERIES ESTABLISHED: Lake County, Montana, 1991; proposed in Lake County, Montana, 1970.
REMARKS: Soil interpretation record: MT0422. Diagnostic horizons and features recognized in this pedon are: a mollic epipedon from the soil surface to 8 inches (Ap horizon); an argillic horizon having interfingering of albic materials from 8 to 10 inches (Bt/E horizon); a natric horizon from 10 to 19 inches (Btn and part of Bkn horizons). Belton soils have a frigid temperature regime and a xeric moisture regime.