LOCATION MACAR MT+UTEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Typic Haplustepts
TYPICAL PEDON: Macar clay loam, in cropland (colors are for dry soil unless otherwise noted).
Ap--0 to 7 inches; grayish brown (2.5Y 5/2) clay loam, dark grayish brown (2.5Y 4/2) moist; weak medium and weak fine blocky structure parting to moderate medium and fine granular; slightly hard, friable, sticky and plastic; organic coating on ped faces is very dark grayish brown (2.5Y 3/2) moist; many fine and very fine roots; many fine and very fine pores; slightly alkaline (pH 7.8); abrupt, smooth boundary. (4 to 8 inches thick)
Bw--7 to 18 inches; grayish brown (2.5Y 5/2) clay loam, dark grayish brown (2.5Y 4/2) moist; moderate medium prismatic structure parting to moderate medium and moderate fine blocky; slightly hard, friable, sticky and plastic; prominent patchy very dark grayish brown (2.5Y 3/2) stains on faces of peds; many fine and very fine roots; many fine and very fine pores; slightly alkaline (pH 7.8); gradual wavy boundary. (6 to 15 inches thick)
Bk1--18 to 29 inches; light olive gray (5Y 6/2) clay loam, olive gray (5Y 4/2) moist; moderate medium and fine blocky structure; hard, friable, sticky and plastic; common fine and very fine roots; few pebbles that have lime coating on underside; common fine and very fine pores; common fine masses and threads of lime; strongly effervescent; moderately alkaline (pH 8.2); gradual wavy boundary.
Bk2--29 to 38 inches; light olive gray (5Y 6/2) sandy clay loam, olive gray (5Y 5/2) moist; massive; slightly hard, friable, sticky and plastic; few fine and very fine roots; few fine pores; few fine masses of lime; disseminated lime; violently effervescent; moderately alkaline (pH 8.2); gradual irregular boundary. (Combined Bk horizons 5 to 50 inches thick)
BC--38 to 60 inches; light gray (5Y 6/1) silt loam, gray (5Y 5/1) moist; massive; slightly hard, friable; nonsticky and nonplastic; disseminated lime; violently effervescent; strongly alkaline (pH 8.8).
TYPE LOCATION: Carbon County, Montana; 1,400 feet west and 1,400 feet south of NE corner of sec. 1, T. 5 S., R. 21 E.
RANGE IN CHARACTERISTICS:
Soil temperature - 42 to 47 degrees F.
Moisture control section - between 4 and 12 inches.
Depth to the Bk horizon - 11 to 24 inches.
Soil phases - cool; saline.
Ap horizon - Hue: 10YR, 2.5Y, or 5Y
Value: 4, 5 or 6 dry; 3, 4, or 5 moist
Chroma: 2, 3, or 4
Texture: loam or clay loam
Clay content: 18 to 35 percent
Rock fragments: 0 to 30 percent--0 to 5 percent cobbles; 0 to 25 percent pebbles
Effervescence: none to slightly
EC: 0 to 2 mmhos/cm
Reaction: pH 6.6 to 8.4; saline phase 7.9 to 8.4
A thin dark colored A horizon that does not meet the requirements for a mollic epipedon after mixing to 7 inches is allowed.
Bw horizon - Hue: 10YR, 2.5Y, or 5Y
Value: 5, 6, or 7 dry; 3, 4, or 5 moist
Chroma: 2, 3, 4, or 6
Texture: loam, clay loam, or silty clay loam
Clay content: 18 to 35 percent
Rock fragments: 0 to 5 percent pebbles
Effervescence: none to slightly
EC: 0 to 8 mmhos/cm; saline phase 4 to 8 mmhos/cm
Reaction: pH 6.6 to 9.0; saline phase 8.5 to 9.0.
Bk horizons - Hue: 10YR, 2.5Y, or 5Y
Value: 5, 6, or 7 dry; 4, 5, or 6 moist
Chroma: 2, 3, 4, or 6
Texture: clay loam, loam, sandy clay loam, silt loam or silty clay loam. Some pedons have fine strata of sandy loam and fine sandy loam in the lower part.
Clay content: 18 to 35 percent with 35 to 55 percent fine sand and coarser.
Rock fragments: 0 to 5 percent pebbles with up to 10 percent in the lower part.
Effervescence: slight or strong in the upper part and strong or violent in the lower part.
Calcium carbonate equivalent: 5 to 15 percent
EC: 0 to 16 mmhos/cm; saline phase 8 to 16 mmhos/cm
Reaction: pH 7.4 to 9.0; saline phase pH 8.5 to 9.0
BC horizon - Hue: 10YR, 2.5Y, or 5Y
Value: 5, 6, or 7 dry; 4, 5, or 6 moist
Chroma: 2, 3, 4, or 6
Texture: loam, silt loam, silty clay loam or sandy clay loam consisting of strata of very fine sandy loam, sandy clay loam, and silt loam
Clay content: 15 to 30 percent
Rock fragments: 0 to 10 percent pebbles
Effervescence: strongly or violently
Calcium carbonate equivalent: 5 to 12 percent
EC: 0 to 16 mmhos/cm; saline phase 8 to 16 mmhos/cm
Reaction: pH 7.9 to 9.0; saline phase 8.5 to 9.0
COMPETING SERIES:
Arikara (ND) - has an O horizon.
Broadus (MT) - has 15 to 35 percent fine sand and coarser throughout the soil; has O horizons.
Doney (MT) - is moderately deep to a paralithic contact.
Eaglewing (MT) - has O and E horizons; has a calcic horizon.
Mara (NM) - is calcareous throughout the profile; is moist in the moisture control section during winter months.
Slategoat (MT) - has an AB horizon and an O horizon; moderately well drained.
GEOGRAPHIC SETTING:
Landform - alluvial fans, stream terraces, sedimentary plains, and hills.
Elevation - 1,900 to 4,700 feet. It ranges up to 6,200 feet in the foothills of the mountains.
Slope- 0 to 75 percent.
Parent material - alluvium and colluvium derived mainly from semiconsolidated sandstone and siltstone sedimentary beds.
Climate -long, cold winters; moist springs; and warm summers.
Mean annual precipitation - 12 to 19 inches. It ranges up to 20 inches in the foothills of the mountains. Most of the precipitation falls in the spring and summer.
Mean annual air temperature - 39 to 45 degrees F.
Frost-free period - 90 to 135 days. It ranges down to 70 days in the foothills of the mountains.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability.
USE AND VEGETATION: Macar soils are used for nonirrigated crops and for range. The potential native vegetation is mainly western wheatgrass, bluebunch wheatgrass, green needlegrass, little bluestem, forbs, and shrubs.
DISTRIBUTION AND EXTENT: Macar soils are extensive in south central Montana. They are also in the state of Utah.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Big Horn County, Montana, 1970.
REMARKS: Soil interpretation records: MT0270, MT0471, MT0768.
Diagnostic horizons and features recognized in this pedon are: ochric epipedon - from the soil surface to 7 inches (Ap horizon); cambic horizon - from 7 to 18 inches (Bw horizon); accumulation of secondary carbonates - from 18 to 38 inches (Bk1, Bk2 horizons); particle-size control section - from 10 to 40 inches (Bw, Bk1, Bk2, BC horizons). Macar soils have a frigid temperature regime and an ustic moisture regime.