LOCATION EFFINGTON WYEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Typic Natrargids
TYPICAL PEDON: Effington clay loam - rangeland. (Colors are for dry soil unless otherwise stated.)
A--0 to 3 inches; light brownish gray (2.5Y 6/2) clay loam, grayish brown (2.5Y 5/2) moist; weak medium platy structure parting to weak fine granular; slightly hard, friable, sticky and plastic; slightly effervescent; calcium carbonate disseminated; strongly alkaline (pH 8.9); abrupt smooth boundary. (1 to 4 inches thick)
Btn1--3 to 14 inches; grayish brown (2.5Y 5/2) clay, dark grayish brown (2.5Y 4/2) moist; weak coarse columnar structure parting to moderate fine angular and subangular blocky; extremely hard, firm, very sticky and very plastic; many distinct clay films on faces of peds; slightly effervescent; calcium carbonate disseminated; very strongly alkaline (pH 9.2); gradual wavy boundary. (5 to 15 inches thick)
Btn2--14 to 19 inches; light brownish gray (2.5Y 6/2) clay, dark grayish brown (2.5Y 4/2) moist; weak coarse subangular blocky structure; extremely hard, firm, very sticky and very plastic; few faint clay films on both vertical and horizontal faces of peds; slightly effervescent, calcium carbonate as few soft masses; few crystals of soluble salts; very strongly alkaline (pH 9.4); gradual smooth boundary. (4 to 11 inches thick)
Bnkyz--19 to 29 inches; light brownish gray (2.5Y 6/2) loam, grayish brown (10YR 5/2) moist; massive; very hard, friable, slightly sticky and slightly plastic; strongly effervescent, calcium carbonate as common soft masses and threads; soluble salts and gypsum as common fine crystals and clusters; very strongly alkaline (pH 9.2); gradual wavy boundary. (4 to 40 inches thick)
C--29 to 60 inches; light brownish gray (2.5Y 6/2) loam, grayish brown (2.5Y 5/2) moist; massive; hard, friable, slightly sticky and slightly plastic; slightly effervescent, calcium carbonate disseminated; few gypsum crystals; strongly alkaline (pH 8.6).
TYPE LOCATION: Fremont County, Wyoming; 1,320 feet north and
220 feet east of the southwest corner of section 15, T.2 N.,
R.3 E.
RANGE IN CHARACTERISTICS: Depth to the base of the natric horizon ranges from 15 to 30 inches. Typically, these soils have free carbonates at the surface due to recharge, but some pedons may be leached to 4 inches. The weighted organic carbon content of the upper 15 inches is less than .4 percent. Coarse fragment content of the entire soil is typically less than 5 percent but may range from 0 to 15 percent pebbles or channers. The mean annual soil temperature ranges from 48 to 51 degrees F., and the mean summer soil temperature ranges from 60 to 68 degrees F.
The A horizon has hue of 2.5Y or 10YR, value of 5 through 7 dry, 4 through 6 moist, and chroma of 2 through 4. Reaction is moderately alkaline through very strongly alkaline. EC ranges from 0 to 12 mmhos.
The Btn or natric horizon has hue of 5Y through 10YR, value of 4 through 7 dry, 4 through 6 moist, and chroma of 2 through 4. It is clay silty clay, silty clay loam, or heavy clay loam with 35 to 55 percent clay, 10 to 50 percent silt, and 15 to 45 percent sand. Exchangeable sodium percentage ranges from 15 to 30 percent. EC ranges from 2 to 16 mmhos. Reaction is very strongly alkaline.
The Bnkyz horizon has hue of 5Y through 10YR, value of 5 through 7 dry, 4 through 6 moist, and chroma of 2 through 4. It is loam, silty clay loam, or clay loam with 15 to 30 percent clay. Exchangeable sodium percentage ranges from 15 to 40 percent. Carbonates range from 4 to 15 percent. EC ranges from 8 to 16 mmhos. Reaction is strongly or very strongly alkaline. The subordinate designators may vary, but this horizon always has an accumulation of carbonate, sodium, gypsum, and salts more soluble than gypsum.
The C horizon has hue of 5Y through 10YR, value of 4 through 7 dry, 3 through 6 moist, and chroma of 2 through 4. Weighted texture is loam, clay loam, silty clay loam, or sandy clay loam. Thin strata of varying textures occur below 30 inches in some pedons. Carbonates, gypsum, and salts are present but are less concentrated than defined for the Bnkyz. Exchangeable sodium ranges from 12 to 30 percent and occurs erratically throughout this horizon. EC ranges from 2 to 16 mmhos but typically averages about 8 mmhos for this horizon. Reaction is strongly alkaline or very strongly alkaline.
COMPETING SERIES: These are the Buckaroo, Calneva(T), Churchill, Kleinbush, McElmo(T), Meeteetse, Tohona, Ultra, Updike, and Uvada series. Buckaroo soils have strong structure in the Btn and do not contain accumulations of soluble salts and gypsum. Calneva soils contain less than 15 percent sand in the natric horizon and have MAST of 53 to 56 degrees F. Churchill soils have a MAST of 55 to 57 degrees F. and have lacustrine deposits at 15 inches or less. Kleinbush soils have buried horizons between 20 and 40 inches. McElmo soils have MAST of 52 to 54 degrees F. Meeteetsee soils have 5YR or 7.5YR hues throughout the natric horizon and substratum. Tohona soils are 20 to 40 inches to shale bedrock. Ultra soils are noncalcareous. Updike soils do not have E horizons. Uvada soils have silty clay loam or silty clay natric horizons and formed in lake and deltaic sediments.
GEOGRAPHIC SETTING: Effington soils are on toeslopes and terraces. The soils formed in alluvium weathered from sodic shales. Slopes are typically less than 3 percent but range from 0 to 8 percent. Elevations range from 5,000 to 6,500 feet. The mean annual precipitation ranges from 5 to 9 inches of which about half falls as rain and snow during April, May, and early June. The mean annual temperature ranges from 43 to 46 degrees F. The frost-free season is estimated to range from 110 to 140.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Binton, Mudray, and Youngston soils. Binton and Youngston soils occupy recent alluvial positions and have fine-loamy control sections. Mudray soils have natric horizons but also have bedrock above 20 inches.
DRAINAGE AND PERMEABILITY: Well drained; very slow through medium runoff; very slow permeability.
USE AND VEGETATION: Rangeland and wildlife habitat. Native vegetation consists of birdfoot sage, bottlebrush squirreltail, bud sagebrush, western wheatgrass, and Gardner saltbush.
DISTRIBUTION AND EXTENT: Basin areas of central and northwestern Wyoming. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Fremont County, Wyoming; 1969.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - 0 to 3 inches (A)
Natric horizon - 3 to 19 inches (Btn1,Btn2)