LOCATION ZAHILL MT+SDEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Typic Calciustepts
TYPICAL PEDON: Zahill clay loam, cultivated. (Colors are for dry soil unless otherwise noted)
Ap--0 to 6 inches; grayish brown (2.5Y 5/2) clay loam, dark grayish brown (2.5Y 4/2) moist; weak fine crumb structure; slightly hard, friable, sticky and plastic; many roots; 5 percent pebbles; disseminated lime; strongly effervescent; moderately alkaline (pH 8.0); clear wavy boundary. (3 to 8 inches thick)
Bk--6 to 30 inches; light brownish gray (2.5Y 6/2) clay loam, dark grayish brown (2.5Y 4/2) moist; weak coarse prismatic structure; hard, friable, sticky and plastic; many fine roots; 5 percent pebbles, 1 percent stones; continuous faint to distinct lime coatings and casts on underside of rock fragments; common fine and medium masses of lime; violently effervescent; moderately alkaline (pH 8.0); clear wavy boundary. (6 to 30 inches thick)
Cy--30 to 60 inches; olive gray (5Y 5/2) clay loam, olive gray (5Y 4/2) moist; weak very thick platy structure parting to moderate fine subangular blocky; hard, firm, sticky and plastic; few lignite chips; 1 percent stones, 5 percent pebbles; common fine crystals of gypsum; disseminated lime; strongly effervescent; moderately alkaline (pH 8.4).
TYPE LOCATION: Sheridan County, Montana; about 200 feet west and 100 feet south of the NE corner of sec. 25, T. 35 N., R. 57 E.
RANGE IN CHARACTERISTICS:
Soil temperature - 40 to 47 degrees F.
Moisture control section - between 4 and 12 inches.
Depth to Bk horizon - 3 to 8 inches.
Soil phases - stony, calcareous, warm.
Uncultivated areas have a thin 1- to 3-inch, none to slightly effervescent, A horizon with value of 4 or 5 dry and 3 moist, and chroma of 1 or 2.
A Bky horizon is allowed.
Ap horizon - Hue: 10YR, 2.5Y or 5Y
Value: 5, 6 or 7 dry; 4, 5 or 6 moist
Chroma: 2, 3 or 4
Texture: loam or clay loam
Clay content: 20 to 35 percent
Rock fragments: 0 to 35 percent--0 to 15 percent cobbles and stones, 0 to 20 percent pebbles
Rock fragments, surface cover: 0.01 to 3 percent stones
Effervescence: slight to violently (the calcareous phase has 5 percent or more calcium carbonate)
Calcium carbonate equivalent: 1 to 10 percent
Reaction: pH 7.4 to 8.4
Bk horizon - Hue: 10YR, 2.5Y or 5Y
Value: 5, 6 or 7 dry; 4, 5 or 6 moist
Chroma: 2, 3 or 4
Texture: loam or clay loam
Clay content: 25 to 35 percent
Rock fragments: 0 to 15 percent--0 to 5 percent stones or cobbles, 0 to 10 percent pebbles
Calcium carbonate equivalent: 8 to 25 percent, but is more than 15 percent in some part.
Effervescence: strongly or violently
Reaction: pH 7.4 to 8.4
C, Cy horizons - Hue: 10YR, 2.5Y or 5Y
Value: 5, 6 or 7 dry, 4, 5 or 6 moist
Chroma: 2, 3 or 4
Texture: loam or clay loam
Clay content: 20 to 35 percent
Rock fragments: 0 to 15 percent--0 to 5 percent stones or cobbles, 0 to 10 percent pebbles
Calcium carbonate equivalent: 2 to 12 percent
Effervescence: slightly or strongly
Gypsum: 1 to 5 percent
Reaction: pH 7.4 to 9.0
COMPETING SERIES:
Frandsen (UT) - does not have high bulk density till above a depth of 60 inches and occurs at elevations of more than 6,800 feet.
GEOGRAPHIC SETTING:
Landform - till plains; hills; moraines; escarpments.
Elevation - 2,000 to 4,000 feet.
Slope- 0 to 65 percent.
Parent material - till.
Climate - cold, dry winters; short, warm summers.
Mean annual precipitation - 12 to 19 inches.
Mean annual air temperature - 38 to 45 degrees F.
Frost-free period - 70 to 130 days.
DRAINAGE AND PERMEABILITY: Well drained; runoff is negligible to high depending on slope; moderately slow permeability above the till, slow in the till.
USE AND VEGETATION: Zahill soils are used mainly range and dryland crops. Potential native vegetation is mainly western wheatgrass, needleandthread, green needlegrass, little bluestem, prairie sandreed, bluebunch wheatgrass, prairie junegrass, blue grama, sedges, and other forbs.
DISTRIBUTION AND EXTENT: Zahill soils are extensive in north-central and northeastern Montana, northwestern North Dakota, and in the north-central part of South Dakota.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Dawson County, Montana, 1971.
REMARKS: Soil interpretation record: MT0025, MT0607, MT1134.
Diagnostic horizons and features recognized in this pedon are: ochric epipedon - the zone from the soil surface to a depth of 7 inches (mixed)(Ap, Bk horizons); calcic horizon - the zone from 6 to 30 inches (Bk horizon); till with crystals of gypsum and lignite chips from 30 to 62 inches (Cy horizon). Zahill soils have a frigid temperature regime and an ustic moisture regime.