LOCATION ZATONY MTEstablished Series
TAXONOMIC CLASS: Fine, mixed, superactive, frigid Aridic Haplustepts
TYPICAL PEDON: Zatony clay loam, in cropland (colors are for dry soil unless otherwise noted).
Ap1--0 to 1 inches; light brownish gray (10YR 6/2) sandy clay loam, dark grayish brown (10YR 4/2) moist; massive; hard, firm, moderately sticky and moderately plastic; common very fine and few fine roots; many very fine vesicular pores; moderately alkaline (pH 8.2); abrupt smooth boundary.
Ap2--1 to 6 inches; light brownish gray (10YR 6/2) clay loam, dark grayish brown (10YR 4/2) moist; weak medium granular structure; slightly hard, friable, moderately sticky and moderately plastic; common very fine roots; many very fine pores; moderately alkaline (pH 8.3); gradual wavy boundary. (Combined thickness of the A horizons is 3 to 8 inches.)
Bknz1--6 to 20 inches; pale brown (10YR 6/3) clay loam, brown (10YR 4/3) moist; weak medium prismatic structure; hard, friable, moderately sticky and moderately plastic; common very fine roots; many very fine pores; common medium masses and seams of soluble salts; disseminated lime, few fine threads of lime; strongly effervescent; strongly alkaline (pH 9.0); gradual irregular boundary. (8 to 14 inches thick)
Bknz2--20 to 36 inches; pale brown (10YR 6/3) clay loam, brown (10YR 4/3) moist; weak coarse prismatic structure; hard, friable, moderately sticky and moderately plastic; few very fine roots; common very fine pores; common medium masses and seams of soluble salts; disseminated lime, few fine threads of lime; violently effervescent; very strongly alkaline (pH 9.6); gradual irregular boundary. (4 to 38 inches thick)
Bknz3--36 to 60 inches; light gray (10YR 7/2) silty clay, brown (10YR 5/3) moist; massive; hard, firm, moderately sticky and moderately plastic; many medium masses and seams of soluble salts; disseminated lime, few fine threads of lime; strongly effervescent; strongly alkaline (pH 8.6).
TYPE LOCATION: Jefferson County, Montana; 800 feet east and 1,650 feet south of the northwest corner of sec. 21 T. 2 N., R. 1 W.
RANGE IN CHARACTERISTICS:
Soil temperature - 42 to 46 degrees F.
Moisture control section - between 4 and 12 inches, dry in all parts between four-tenths and five-tenths of the cumulative days per year when the soil temperature at a depth of 20 inches is 41 degrees F or higher.
Depth to Bknz1 horizon - 3 to 8 inches.
The surface layer, when mixed to 7 inches, does not meet the color requirements for a mollic epipedon.
A horizons - Hue: 10YR or 2.5Y
Value: 5 or 6 dry
Chroma: 2 or 3
Texture: clay loam or silt loam (mixed)
Clay content: 20 to 40 percent
Calcium carbonate equivalent: 0 to 5 percent
Electrical conductivity: 2 to 16 mmhos/cm
Sodium adsorption ratio: 4 to 20
Reaction: pH 7.4 to 9.0
Bknz1, Bknz2 horizons - Hue: 10YR or 2.5Y
Value: 5, 6, or 7 dry; 4 or 5 moist
Chroma: 2 or 3
Texture: clay loam, silty clay loam, silty clay, or clay
Clay content: 35 to 45 percent
Calcium carbonate equivalent: 3 to 15 percent
Electrical conductivity: 16 to 32 mmhos/cm
Sodium adsorption ratio: 13 to 60
Reaction: pH 7.9 to 9.6
Bknz3 horizon - Hue: 10YR or 2.5Y
Value: 5, 6, or 7 dry; 4 or 5 moist
Chroma: 2 or 3
Texture: clay loam, silty clay loam, silty clay, or clay
Clay content: 28 to 45 percent
Calcium carbonate equivalent: 2 to 10 percent
Electrical conductivity: 16 to 32 mmhos/cm
Sodium adsorption ratio: 13 to 40
Reaction: pH 7.9 to 9.0
COMPETING SERIES:
Alzada (MT) - has horizon of gypsum accumulation; has a lithologic discontinuity.
Kobarter (MT) - does not have a horizon of sodium accumulation; has an EC range of 4 to 16 in the Bkz horizon and below.
GEOGRAPHIC SETTING:
Landform - alluvial fans, stream terraces, flood plain steps and drainageways.
Elevation - 3,800 to 5,000 feet.
Slope- 0 to 8 percent.
Parent material - alluvium derived primarily from semiconsolidated shale.
Climate - cold, dry winters; moist springs; hot summers.
Mean annual precipitation - 10 to 14 inches.
Mean annual air temperature - 40 to 44 degrees F.
Frost-free period - 90 to 115 days.
DRAINAGE AND PERMEABILITY: Well drained, slow permeability.
USE AND VEGETATION: Zatony soils are primarily used for rangeland and to a limited extent for irrigated and nonirrigated cropland. The potential native vegetation is mainly western wheatgrass, green needlegrass, basin wild rye, Sandberg bluegrass, inland saltgrass, big sagebrush, Nuttall saltbush, and greasewood.
DISTRIBUTION AND EXTENT: Zatony soils are of small extent in southwestern Montana.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Jefferson County, Montana, 1998.
REMARKS: Soil interpretation records: MT1591. Diagnostic horizons and features recognized in this pedon are: an ochric epipedon from the soil surface to 7 inches, mixed (Ap1, Ap2, Bknz1 horizons); a particle-size control section from 10 to 40 inches (Bknz1, Bknz2, Bknz3 horizons); horizons of soluble salt, secondary calcium carbonate, and sodium accumulations from 6 to 60 inches (Bknz1, Bknz2, Bknz3 horizons). Zatony soils have a frigid temperature regime and an ustic moisture regime bordering on aridic.