LOCATION DONALD MT
Established Series
Rev. BDD-KTS-RJS
03/2012
DONALD SERIES
The Donald series consists of very deep, well drained soils that formed in alluvium. These soils are on fan remnants, alluvial fans, stream terraces, hills and mountain slopes. Slopes are 0 to 35 percent. Mean annual precipitation is about 18 inches, and mean annual air temperature is about 37 degrees F.
TAXONOMIC CLASS: Fine, smectitic Abruptic Argicryolls
TYPICAL PEDON: Donald loam, in rangeland (colors are for dry soil unless otherwise noted).
A1--0 to 5 inches; very dark gray (10YR 3/1) loam, black (10YR 2/1) moist; moderate medium subangular blocky structure parting to strong medium granular; hard, firm, slightly sticky and slightly plastic; many very fine, fine and medium roots; many very fine tubular pores; 5 percent gravel; neutral (pH 6.6); clear smooth boundary. (4 to 8 inches thick)
A2--5 to 9 inches; dark grayish brown (10YR 4/2) loam, very dark grayish brown (10YR 3/2) moist; moderate medium subangular blocky structure parting to strong medium granular; hard, firm, slightly sticky and slightly plastic; many very fine, fine and medium roots; many very fine tubular pores; 5 percent gravel, 5 percent stones; neutral (pH 7.0); clear wavy boundary. (3 to 5 inches thick)
E--9 to 13 inches; pinkish gray (7.5YR 7/2) sandy loam, brown (7.5YR 5/2) moist; weak coarse subangular blocky structure; hard, firm, nonsticky and nonplastic; many very fine, fine and medium roots; many fine irregular pores; 5 percent gravel, 5 percent cobbles, 3 percent stones; neutral (pH 6.8); abrupt wavy boundary. (0 to 9 inches thick)
Bt1--13 to 16 inches; light brown (7.5YR 6/4) clay, brown (7.5YR 5/4) moist; strong medium columnar structure; very hard, very firm, very sticky and very plastic; common fine roots; few very fine and fine tubular pores; many continuous distinct unstained sand grains on tops of columns and discontinuous distinct unstained sand grains on vertical faces of peds; many distinct clay films on vertical faces of peds and in pores; neutral (pH 7.2); clear wavy boundary.
Bt2--16 to 23 inches; light brown (7.5YR 6/4) clay, brown (7.5YR 5/4) moist; moderate medium prismatic structure; very hard, very firm, very sticky and very plastic; common fine roots; few very fine and fine tubular pores; many distinct clay films on faces of peds and in pores; slightly alkaline (pH 7.8); clear wavy boundary. (Combined thickness of Bt horizons - 10 to 20 inches)
Btk--23 to 35 inches; light brown (7.5YR 6/4) clay, brown (7.5YR 5/4) moist; moderate medium angular blocky structure; very hard, very firm, very sticky and very plastic; few fine roots; common fine and few medium tubular pores; common distinct clay films on faces of peds and in pores, common medium irregular seams of calcium carbonate; slightly effervescent on faces of peds; moderately alkaline (pH 8.2); clear wavy boundary. (8 to 19 inches thick)
BC--35 to 60 inches; light brown (7.5YR 6/4) clay, light brown (7.5YR 6/4) moist; massive; hard, firm, moderately sticky and moderately plastic; few fine tubular pores; moderately alkaline (pH 8.2).
TYPE LOCATION: Granite County, Montana; 2,300 feet east and 1,500 feet north of SW corner of sec. 17, T 5 N., R. 14 W.
RANGE IN CHARACTERISTICS:
Soil temperature - 35 to 41 degrees F.
Depth to top of argillic horizon - 11 to 22 inches
Depth to secondary calcium carbonate accumulation - 21 to 40 inches
In cultivated areas the upper few inches of the columnar structure may be destroyed.
Note: Some pedons may have an E/Bt, Bt/E and/or Bk horizon.
A1 horizon
Value: 2 to 4 dry, 2 or 3 moist
Chroma: 1 or 2; dry or moist
Texture: loam or silt loam
Clay content: 18 to 27 percent
Rock fragments: 0 to 35 percent--0 to 15 percent gravel, 0 to 20 percent cobbles, 0 to 5 percent stones
Reaction: pH 6.6 to 7.3
A2 horizon
Value: 3 or 4 dry; 2 or 3 moist
Texture: loam or silt loam
Clay content: 18 to 27 percent
Rock fragments: 0 to 35 percent--0 to 15 percent gravel, 0 to 20 percent cobbles, 0 to 20 percent stones
Reaction: pH 6.6 to 7.3
E horizon
Hue: 10YR or 7.5YR; dry or moist
Value: 6 or 7 dry; 5 or 6 moist
Texture: loam or sandy loam
Clay content: 18 to 27 percent
Rock fragments: 0 to 15 percent--0 to 5 percent gravel, 0 to 5 percent cobbles, 0 to 5 percent stones
Reaction: pH 6.6 to 7.3
Bt1 horizon
Hue: 10YR or 7.5YR; dry or moist
Value: 4 to 6 dry; 3 to 5 moist
Chroma: 3 or 4; dry or moist
Texture: clay, silty clay or clay loam
Clay content: 35 to 60 percent
Rock fragments: 0 to 15 percent gravel
Reaction: pH 6.6 to 7.8
Bt2 horizon
Hue: 10YR or 7.5YR; dry or moist
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 3 or 4; dry or moist
Texture: clay loam, silty clay or clay
Clay content: 35 to 60 percent
Rock fragments: 0 to 15 percent gravel
Reaction: pH 6.6 to 7.8
Btk horizon
Hue: 10YR or 7.5YR; dry or moist
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 3 or 4; dry or moist
Texture: clay loam, silty clay loam or clay
Clay content: 35 to 60 percent
Rock fragments: 0 to 35 percent gravel
Calcium carbonate equivalent: 1 to 5 percent
Reaction: pH 7.4 to 8.4
BC horizon
Hue: 10YR or 7.5YR; dry or moist
Value: 5 or 6 dry; 4 to 6 moist
Chroma: 3 or 4; dry or moist
Texture: clay loam or clay
Clay content: 35 to 60 percent
Rock fragments: 0 to 5 percent gravel
Calcium carbonate equivalent: 0 to 5 percent
Reaction: pH 7.4 to 8.4
Bk horizon (if present)
Hue: 10YR or 7.5YR; dry or moist
Value: 6 or 7 dry; 5 or 6 moist
Chroma: 2 to 4; dry or moist
Texture: clay loam or loam
Clay content: 20 to 40 percent
Rock fragments: 0 to 15 percent gravel
Calcium carbonate equivalent: 5 to 15 percent
Reaction: pH 7.9 to 8.4
COMPETING SERIES:
Cebolia (CO) - have hues of 5YR and 10R in the argillic horizon
GEOGRAPHIC SETTING:
Landform - fan remnants, alluvial fans, stream terraces, hills and mountain slopes
Elevation - 5,500 to 8,500 feet
Slope - 0 to 35 percent
Parent material - alluvium or colluvium
Climate - long, cold winters; moist springs; warm summers
Mean annual precipitation - 14 to 22 inches
Mean annual air temperature - 34 to 45 degrees F.
Frost-free period - 30 to 70 days
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND PERMEABILITY: Well drained; slow permeability.
USE AND VEGETATION: Donald soils are used mainly for pasture, grass hay, and irrigated grass hay. Native vegetation is mainly rough fescue, Idaho fescue, shrubby cinquefoil, and forbs.
DISTRIBUTION AND EXTENT: Donald soils are of small extent in southwestern Montana. MLRAs - 43B, 44B.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana.
SERIES ESTABLISHED: Granite County (Philipsburg-Drummond Area), Montana, 1972.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - from 0 to 9 inches (A1, A2 horizons
Albic horizon - from 9 to 13 inches (E horizon)
Argillic horizon - from 13 to 35 inches (Bt1, Bt2, Btk horizons)
Horizon with secondary calcium carbonate accumulation - from 23 to 35 inches (Btk horizon)
Particle-size control section from 13 to 33 inches (Bt1, Bt2, part of Btk horizons)
Donald soils have a cryic temperature regime and an ustic moisture regime.
ADDITIONAL DATA: Soil interpretation record: MT0558.
Additional Information: Based on the profile description the Donald series was re-classified from Alfic Argicryolls to Abruptic Argicryolls (3/14/2012).
National Cooperative Soil Survey
U.S.A.