LOCATION ABSTED WY+SDEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Haplic Ustic Natrargids
TYPICAL PEDON: Absted very fine sandy loam-on south facing slope of about one percent under native grass vegetation. (Colors are for dry soil unless otherwise stated)
E--0 to 2 inches; light gray (10YR 7/2) fine sandy loam, very dark grayish brown (10YR 3/2) moist; strong thick platy structure parting to strong thin platy; slightly hard, very friable, slightly sticky and nonplastic; common fine and very fine roots; slightly alkaline (pH 7.6); abrupt smooth boundary. (0 to 8 inches thick)
Bt--2 to 8 inches; brown (10YR 5/3) clay, dark grayish brown (10YR 4/2) moist; strong medium columnar structure parting to strong medium and fine angular blocky; very hard, firm, sticky and plastic; few fine and medium roots; many prominent clay films on faces of peds; moderately alkaline (pH 8.2); clear smooth boundary. (5 to 16 inches thick)
Btkn--8 to 13 inches; brown (10YR 5/3) clay, dark grayish brown (10YR 4/2) moist; strong medium angular blocky structure; very hard, friable, sticky and plastic; few fine and medium roots; common distinct clay films on faces of peds; strongly effervescent; calcium carbonate and gypsum as common fine filaments and threads; strongly alkaline (pH 8.8); clear smooth boundary. (4 to 15 inches thick)
Bkn--13 to 60 inches; pale brown (10YR 6/3) clay loam, dark grayish brown (10YR 4/2) moist; moderate coarse subangular blocky structure; very hard, firm, sticky and plastic; strongly effervescent; many prominent threads of calcium carbonate and gypsum; very strongly alkaline (pH 9.0).
TYPE LOCATION: Sheridan County, Wyoming; SE 1/4, of the NE 1/4 of section 32, T.55 N, R 79 W. 44 degrees 42 minutes 49 seconds north latitude and 106 degrees 25 minutes 14 seconds west longitude.
RANGE IN CHARACTERISTICS: Depth to horizons of continuous calcium carbonate accumulations is 6 to 20 inches. Depth to layers with ESP greater than 15 is more than 7 inches. Rock fragments in the control section range from 0 to 15 percent and is mostly gravel. These soils are usually dry, but are moist in some or all parts of the moisture control section in April, May, and early June in most years. The moisture control section is dry for more than 60 consecutive days during the 90 day period following the summer solstice. The mean annual soil temperature is 47 to 53 degrees F. The soil temperature at 20 inches is 41 degrees F. or warmer for 175 to 195 days. Organic carbon in upper 40 cm. of the profile is .6 to .8 percent.
The A horizon has hue of 10YR, 2.5Y or 5Y; 10YR hue has value of 5 to 7 dry and 3 to 6 moist, and chroma of 2 or 3; 2.5Y and 5Y hues have value of 5 or 6 dry and 4 or 5 moist. Textures are sandy loam, sandy clay loam, fine sandy loam, very fine sandy loam or loam. Reaction is neutral or slightly alkaline.
The E horizon has hue of 10YR, 2.5Y or 5Y; 10YR hue has value of 5 to 7 dry and 3 to 6 moist, and chroma of 2 or 3. Textures are silty clay loam, fine sandy loam, very fine sandy loam, silt loam, loam or clay loam. Reaction is typically neutral through moderately alkaline but is slightly acid in some pedons. This horizon is absent in some pedons.
The Bt horizon has hue of 10YR, 2.5Y or 7.5YR; 10YR and 2.5Y hues have value of 4 to 7 dry and 3 to 5 moist, and chroma of 2 to 4; 7.5YR hue has chroma 3 or 4; Textures are silty clay, clay, clay loam or silty clay loam with clay ranging from 35 to 50 percent, silt from 15 to 50 percent, and sand from 10 to 45 percent. Exchangeable sodium is 3 to 12 percent. It is slightly alkaline to strongly alkaline.
The Btkn horizon has hue of 10YR, 2.5Y or 5Y, value of 5 or 6 dry and 4 or 5 moist, and chroma of 2 or 3 in 10YR hue and 2 to 4 in 2.5Y hue. Textures are the same as for the Bt horizon. Reaction is strongly or very strongly alkaline. Exchangeable sodium is greater than 15 percent. Salinity is 4 to 15 mmhos/cm.
The Bkn or Bkny horizons have hue of 10YR, 2.5Y or 5Y, value of 5 to 7 dry and 4 to 6 moist, and chroma of 2 or 3 in 10YR hue and 2 to 4 in 2.5Y and 5Y. Textures are the same as for the Bt and Btkn horizons. Exchangeable sodium is 10 to 30 percent. Calcium carbonate equivalent is 6 to 15 percent. Salinity ranges from 8 to 16 mmhos/cm. Reaction is moderately through very strongly alkaline.
The C horizon, when present, has the same range in texture, reaction, and color as the Bkn horizon. Exchangeable sodium is 10 to 30 percent.
COMPETING SERIES: This the Lohsman series. Lohsman soils have a paralithic contact at a depth of 20 to 40 inches.
GEOGRAPHIC SETTING: Absted soils are on hillslopes, terraces, fan remnants, alluvial fans, piedmonts and fan aprons. Slopes are 0 to 25 percent. These soils formed in alluvium derived from alkaline shale. Some areas have an eolian influence on the surface layer. Elevation is 3500 to 5500 feet. The mean annual precipitation is 10 to 14 inches with more than half falling in April, May and June. The frost-free period is 105 to 130 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Lohsman and the Arvada, Bidman, Bone, Cambria and Forkwood soils. Arvada soils have more an exchangeable sodium percent of more than 15 in more than half of the natric horizon. Bidman, Bone, Cambria and Forkwood soils do not have a natric horizon.
DRAINAGE AND PERMEABILITY: Well drained; slow to rapid runoff; slow permeability.
USE AND VEGETATION: These soils are used for livestock grazing and wildlife habitat. Small areas are farmed in crop fallow systems. Native vegetation is mainly western wheatgrass, needleandthread, blue grama and green needlegrass.
DISTRIBUTION AND EXTENT: North-central and north-eastern Wyoming and western South Dakota. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Johnson County, Wyoming, South Part; 1971.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Albic horizon - 0 to 2 inches; (E)
Natric horizon - 2 to 13 inches (Bt, Btkn)
SIR- WY1246
LRR=G