LOCATION MCCALLA MT
Established Series
Rev. EMR-JMS-RJS
07/2013
MCCALLA SERIES
The McCalla series consists of very deep, poorly drained soils formed in alluvium. These soils are on inset fans and in drainageways. Slopes are 0 to 4 percent. Mean annual precipitation is about 330 mm, and mean annual temperature is about 6 degrees C.
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Typic Endoaquolls
TYPICAL PEDON: McCalla loam, in irrigated hayland on 1 percent slope at 1,100 meters elevation (colors are for moist soil unless otherwise stated).
A--0 to 36 cm; black (10YR 2/1) moist, cobbly loam; dark gray (10YR 4/1) dry; moderate medium granular structure; friable, hard, slightly sticky, slightly plastic; many fine and few medium roots; common fine irregular pores; 5 percent medium prominent yellowish brown (10YR 5/8) moist redox concentrations; 5 percent gravel and 10 percent cobbles; slightly alkaline (pH 7.4); gradual smooth boundary. (25 to 38 cm thick)
Bw--36 to 56 cm; dark grayish brown (10YR 4/2) moist, very cobbly loam; light brownish gray (10YR 6/2) dry; weak fine subangular blocky structure; friable, slightly hard, slightly sticky, slightly plastic; common fine and medium roots; common medium irregular pores; 20 percent medium prominent olive yellow (2.5Y 6/6) moist redox concentrations; 15 percent gravel and 25 percent cobbles; neutral (pH 7.2); gradual smooth boundary. (15 to 32 cm thick)
C1--56 to 81 cm; dark grayish brown (2.5Y 4/2) moist, very cobbly sandy loam; light brownish gray (2.5Y 6/2) dry; massive; very friable, soft, nonsticky, nonplastic; few fine and medium roots; common medium irregular pores; 40 percent medium prominent olive yellow (2.5Y 6/6) moist redox concentrations; 25 percent gravel and 20 percent cobbles; neutral (pH 6.8); gradual wavy boundary.
C2--81 to 152 cm; dark grayish brown (2.5Y 4/2) moist, very gravelly loamy sand; light brownish gray (2.5Y 6/2) dry; single grain; loose, nonsticky, nonplastic; many medium irregular pores; 35 percent gravel and 20 percent cobbles; neutral (pH 6.8).
TYPE LOCATION: Ravalli County, Montana; 700 meters north and 370 meters west of the SE corner of section 26, T9N, R20W; USGS Stevensville, Montana topographic quadrangle; North American Datum 83, Zone 11, UTM 724638 meters E, 5154577 meters N.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 5 to 8 degrees C
Mollic epipedon thickness - 25 to 38 cm
Depth to seasonal high water table - 30 to 60 cm
Depth to distinct or prominent redox concentrations - 20 to 38 cm
A horizon:
Hue: 10YR or 2.5Y
Value: 2 or 3 moist; 4 or 5 dry
Chroma: 1 or 2 moist or dry
Texture: loam or silt loam
Clay content: 18 to 27 percent
Rock fragments: 0 to 35 percent--0 to 35 percent gravel; 0 to 25 percent cobbles; 0 to 5 percent stones
Reaction: pH 6.6 to 7.8
Bw horizon:
Hue: 10YR or 2.5Y
Value: 4 or 5 moist; 6 or 7 dry
Chroma: 2 or 3 moist; 2, 3 or 4 dry
Texture: loam or silt loam
Clay content: 16 to 24 percent
Rock fragments: 35 to 65 percent--5 to 45 percent gravel; 5 to 25 percent cobbles; 0 to 5 percent stones
Reaction: pH 6.6 to 7.8
C1 horizon:
Hue: 10YR or 2.5Y
Value: 4 or 5 moist; 6 or 7 dry
Chroma: 2 or 3 moist; 2, 3 or 4 dry
Texture: sandy loam or coarse sandy loam
Clay content: 8 to 18 percent
Rock fragments: 35 to 75 percent--25 to 70 percent gravel; 5 to 25 percent cobbles; 0 to 5 percent stones
Reaction: pH 6.6 to 7.8
C2 horizon:
Hue: 10YR or 2.5Y
Value: 4 or 5 moist; 6 or 7 dry
Chroma: 2 or 3 moist; 2, 3 or 4 dry
Texture: loamy sand, loamy coarse sand, or sand
Clay content: 0 to 12 percent
Rock fragments: 35 to 75 percent--25 to 70 percent gravel; 5 to 25 percent cobbles; 0 to 5 percent stones
Reaction: pH 6.6 to 7.6
COMPETING SERIES:
Allwit (ID) - have less than 18 percent clay and do not have rock fragments larger than 75 mm in the upper part of the subsoil
Irim (CO+MT) - have horizons of strong gleying; have more than 18 percent clay throughout the subsoil; have hue redder than 10YR
Lehmandow (NV) - have horizons of strong gleying; have more than 20 percent clay throughout the subsoil; have more than 5 percent rock fragments of 250 to 600 mm
Poronto (MT) - have horizons of strong gleying; have more than 24 percent clay in the upper part of the subsoil and more than 12 percent clay in the lower part
Swampcreek (MT) - have horizons of strong gleying and secondary calcium carbonate accumulation
GEOGRAPHIC SETTING:
Landform - inset fans and drainageways
Slopes - 0 to 4 percent
Elevation - 1,000 to 1,505 meters
Parent material - alluvium derived from mixed sources
Climate - cold winters; moist springs; warm summers
Mean annual precipitation - 305 to 380 mm
Mean annual air temperature - 4 to 7 degrees C
Frost-free period - 90 to 115 days
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND PERMEABILITY: poorly drained; moderate permeability to a depth of 56 cm and moderately rapid and rapid below.
USE AND VEGETATION: McCalla soils are used mainly for irrigated hayland and pasture.
DISTRIBUTION AND EXTENT: McCalla soils are of small extent in western Montana valleys. MLRA 44A.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Bitterroot Valley Area, Montana, 2013; proposed in Ravalli County, Montana, 2012.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - from the soil surface to 36 cm (A horizon)
Cambic horizon - from 36 to 56 cm (Bw horizon)
Redox concentrations - from 20 to 81 cm (part of the A, Bw and C1 horizons)
Particle-size control section - from 25 to 100 cm (part of the A, Bw, C1, and part of the C2 horizons).
McCalla soils have a frigid temperature regime and an aquic moisture regime.
National Cooperative Soil Survey
U.S.A.