LOCATION HARLAN WYEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Aridic Argiustolls
TYPICAL PEDON: Harlan loam-rangeland. (Colors are for dry soil unless otherwise stated.)
A--0 to 5 inches; brown (7.5YR 5/3) loam, dark brown (7.5YR 3/3) moist; strong very fine granular structure; soft, very friable; neutral (pH 7.2); clear smooth boundary. (3 to 6 inches thick)
B--5 to 8 inches; reddish brown (5YR 5/3) heavy loam, dark reddish brown (5YR 3/3) moist; moderate medium prismatic structure parting to moderate medium subangular blocky; hard, very friable; few thin clay films on faces of some peds; neutral (pH 7.2); clear smooth boundary. (3 to 4 inches thick)
Bt--8 to 20 inches; reddish brown (5YR 5/4) light clay loam, reddish brown (5YR 4/4) moist; strong medium prismatic structure parting to strong medium angular and subangular blocky; very hard, very friable; thin continuous clay films on faces of peds and in root channels and pores; mildly alkaline (pH 7.4); clear wavy boundary. (5 to 20 inches thick)
Btk--20 to 26 inches; light reddish brown (5YR 6/4) heavy loam, reddish brown (5YR 5/4) moist; moderate medium prismatic structure parting to moderate medium subangular blocky; hard, very friable; common thin clay films on some faces of peds and in some root channels; strongly effervescent, some visible secondary calcium carbonate occurring as concretions and in thin seams and streaks; moderately alkaline (pH 8.0); gradual wavy boundary. (0 to 10 inches thick)
Bk--26 to 60 inches; light reddish brown (5YR 6/4) loam, reddish brown (5YR 5/4) moist; massive; hard, very friable; strongly effervescent, visible secondary calcium carbonate occurring as concretions and in seams and streaks; moderately alkaline (pH 8.2);
TYPE LOCATION: Johnson County, Wyoming; NW1/4 SW1/4 sec. 35, T.44N., R83W.
RANGE IN CHARACTERISTICS: Thickness of the mollic epipedon ranges from 6 to 20 inches. Depth to calcareous material ranges from 8 to 20 Rev. PSD 880414
Organic carbon in the mollic epipedon ranges from .8 to 3 percent and decreases uniformly with depth. The soil is 90 to 100 percent base saturated. Rock fragments range from 0 to 15 percent but are typically less than 5 percent. Mean annual soil temperature ranges from 47 to 53 degrees F.
The A horizon has hue of 7.5YR or 5YR, value of 4 or 5 dry, 2 or 3 moist and chroma of 2 or 3. It is neutral or mildly alkaline.
The Bt horizon has hue of 5YR or 2.5YR, value of 5 or 6 dry, 3 through 5 moist and chroma of 3 through 5. It is light clay loam or heavy loam and has 18 to 35 percent clay with more than 15 percent but less than 35 percent fine sand or coarser. It is neutral or mildly alkaline.
The Bk horizon has hue of 5YR or 2.5YR, value of 5 through 7 dry, 4 through 6 moist, and chroma of 2 through 6. It has 6 to about 20 percent calcium carbonate equivalent; but when it exceeds 15 percent, the horizon is thin and discontinuous. It is moderately alkaline to strongly alkaline.
COMPETING SERIES: These are the Ascalon, Asparas, Bresser, Capulin, Cedak, Critchell, Dagflat, Datil, Featherlegs, Hargreave, Hemmingford, Hirac, Kirtley, Lavate, Lorac, Moskee, Noden, Palmer Canyon, Recluse, Rosebud, Ryegate, Satanta, Sugardee, Wages, and Wolf. The Ascalon, Asparas, Bresser, Capulin, Datil, Featherlegs, Moskee, Noden, Palmer Canyon, Recluse, Satanta, Wages, and Wolf soils have hue of 7.5YR or yellower in the Bt horizon. The Cedak, Dagflat, Hargreave, Hemmingford, Hirac, Kirtley, Rosebud and Ryegate soils have bedrock at 20 to 40 inches. The Critchell, Lavate, and Lorac soils are free of carbonates above 40 inches. Sugardee soils have gravelly or channery substrata.
GEOGRAPHIC SETTING: These soils are on gently to moderately sloping relict alluvial fans, terraces, and valley sideslopes. Slope gradients are usually 0 to 20 percent. These soils formed in calcareous sediments of low aggregate stability derived principally from redbed shales and interbedded siltstone and sandstone. Elevations range from 3,500 to 6,000 feet. The mean annual precipitation is 12 to 19 inches with peak periods of precipitation during the spring and early summer. Mean annual temperature is 45 degrees F. The frost-free period is estimated to range from 95 to 125 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Kirtley soils and the LaLande soils. LaLande soils lack a mollic epipedon and an argillic horizon.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderate permeability.
Rev. PSD 880414
USE AND VEGETATION: Used principally as rangeland and wildlife habitat but is tilled to irrigated or dryland crops in some areas. Principal native vegetation is blue grama, western wheatgrass, sagebrush, and cactus.
DISTRIBUTION AND EXTENT: North-central Wyoming. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Johnson County (Southern Johnson Area), Wyoming; 1971.
The superactive cation exchange activity class was added in 03/2003 to the taxonomic classification by the National Soil Survey Center on request of the Reno MLRA office, without review of the soil series property data. The remainder of this document has not been updated.