LOCATION RAIRDENT WY+UTEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Typic Haplogypsids
TYPICAL PEDON: Rairdent loam-rangeland. (Colors are for dry soil unless otherwise stated.)
A--0 to 2 inches; yellowish brown (10YR 5/4) loam, yellowish brown (10YR 5/4) moist; weak fine granular structure; soft, very friable, moderately sticky and moderately plastic; many very fine, fine, and few medium roots; slightly effervescent, carbonates disseminated; moderately alkaline (pH 8.0); abrupt smooth boundary. (2 to 5 inches thick)
Bw--2 to 7 inches; yellowish brown (10YR 5/4) loam, yellowish brown (10YR 5/4) moist; weak medium prismatic structure parting to weak medium and fine subangular blocky; slightly hard, friable, moderately sticky and moderately plastic; many very fine, fine, and few medium roots; strongly effervescent, carbonates disseminated; moderately alkaline (pH 8.0); abrupt wavy boundary. (0 to 15 inches thick)
Bky--7 to 45 inches; light yellowish brown (10YR 6/4) loam, light olive brown (2.5Y 5/4) moist; massive; slightly hard, very friable, moderately sticky and moderately plastic, few very fine, fine, and medium roots; strongly effervescent, carbonates as few soft masses and disseminated; many fine, medium, and large soft masses, seams, and crystals of gypsum; slightly alkaline (pH 7.8); gradual wavy boundary. (20 to 45 inches thick)
By--45 to 60 inches; pale yellow (2.5Y 7/4) loam, light yellowish brown (2.5Y 6/4) moist; massive; slightly hard, friable, moderately sticky and moderately plastic; few very fine, fine, and medium roots; slightly effervescent, carbonates disseminated; many large crystals of gypsum; slightly alkaline (pH 7.6); clear wavy boundary.
TYPE LOCATION: Fremont County, Wyoming; about 1,800 feet north and 2,200 feet east of the SW corner sec. 25, T. 40 N., R. 90 W.
RANGE IN CHARACTERISTICS: These soils are typically calcareous throughout but may be leached a few inches in some pedons. Depth to the top of the gypsic horizon ranges from 7 to 21 inches, and depth to bedrock exceeds 60 inches. The mean annual soil temperature ranges from 47 to 51 degrees F., and the mean summer soil temperature ranges from 59 to 68 degrees F. The particle size control section is typically loam or clay loam, but clay ranges from 18 to 35 percent, silt from 10 to 60 percent, and sand from 15 to 60 percent with more than 15 percent being fine sand or coarser. Coarse fragments are typically less than 15 percent but may range from 0 to 35 percent pebbles with a few cobbles. Salts more soluble than gypsum occur in most pedons but are concentrated in the Bky and By horizons in only a few pedons where salt lenses are present in parent sediments. ESP ranges from about 5 to 15.
The A horizon has hue of 5Y through 10YR, value of 5 through 7 dry, 4 through 6 moist, and chroma of 2 through 4. EC ranges from 2 to 4 mmhos. Reaction is slightly or moderately alkaline.
The Bw horizon has hue of 5Y through 7.5 YR, value of 4 through 7 dry, 3 through 6 moist, and chroma of 2 through 4. Texture is typically loam or clay loam but may range through the limits stated above. EC ranges from 2 to 8 mmhos. Reaction is slightly or moderately alkaline.
The Bky and By horizons have hue of 5Y through 10YR, value of 4 through 8 dry, 4 through 7 moist, and chroma of 2 through 4. Texture is typically loam or clay loam but may range the limits as stated in the preceding paragraph. These horizons are always strongly or violently effervescent and about half contain segregated lime. Because of the variability of salt accumulations in these horizons, a By2 or Bky2 is allowed as long as the requirements of a gypsic horizon are met. EC ranges from 2 to 16 mmhos. Reaction is typically slightly or moderately alkaline.
Clay content: 18-35%
Gypsum content: 5-10%
Carbonate content: 5-15%
A C horizon is present in some pedons.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Rairdent soils are on dissected alluvial fan aprons and older alluvial terraces. These soils formed in gypsiferous alluvial sediments weathered from shale interbedded with sandstone and siltstone. Slopes are 0 to 10 percent. Elevations range from 3,800 to 6,000 feet. The mean annual precipitation is about 7 inches and ranges from 5 to 9 inches with about half following as rain or snow in April, May, and early June. The mean annual temperature is about 47 degrees F. and ranges from about 44 to 50 degrees F. The frost-free season is estimated to be about 110 to 140 days depending upon aspect, elevation, and air drainage.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Clifsand, Emblem, and Uffens soils. Clifsand soils are skeletal and have a calcic horizon. They occur on ridge and hillslopes upslope from the Rairdent soils. Emblem soils have skeletal substrata, calcic horizons, and occur intermixed with the Clifsand soils. Uffens soils have a natric horizon and occur on more stable areas receiving additional moisture from upslope.
DRAINAGE AND PERMEABILITY: Well drained; slow or medium runoff; moderate permeability.
USE AND VEGETATION: Rangeland and wildlife habitat. Native vegetation consists of needleandthread, western wheatgrass, big sagebrush, bluebunch wheatgrass, and Indian ricegrass.
DISTRIBUTION AND EXTENT: Basin areas in western Wyoming and eastern Utah. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Big Horn County, Wyoming, Big Horn Irrigated Area; 1972.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon from the soil surface to 7 inches (A and Bw horizons);
Gypsic horizon from 7 to 60 inches (Bky and By horizons);
Particle-size control section from 10 to 40 inches.;
Mesic temperature regime and a typic aridic moisture regime.