LOCATION WALL WYEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, mesic Typic Haplocambids
TYPICAL PEDON: Wall fine sandy loam - native grassland. (Colors are for dry soil unless otherwise noted.)
A--0 to 6 inches; light brownish gray (10YR 6/2) fine sandy loam, dark grayish brown (10YR 4/2) moist; moderate fine granular structure; soft, very friable; neutral (pH 7.2); clear smooth boundary. (4 to 10 inches thick)
Bw1--6 to 22 inches; brown (10YR 5/3) sandy loam, brown (10YR 4/3) moist; moderate medium subangular blocky structure; soft, very friable; some of the sand grains have bridges of gelatinous material between them; slightly alkaline (pH 7.4); clear wavy boundary. (8 to 24 inches thick)
Bw2--22 to 28 inches; dark grayish brown (10YR 4/2) moist; weak medium subangular blocky structure; soft, very friable; calcareous; moderately alkaline (pH 8.0); gradual wavy boundary. (3 to 6 inches thick)
Bk--28 to 60 inches; light brownish gray (10YR 6/2) light sandy loam, dark grayish brown (10YR 4/2) moist; massive; soft very friable; some visible secondary calcium carbonate occurring as concretions and in thin seams and streaks; calcareous; moderately alkaline (pH 8.2).
TYPE LOCATION: Fremont County, Wyoming; approximately 280 feet north and 80 feet east of the center of sec. 20, T. 3N., R. 1E.
RANGE IN CHARACTERISTICS: Depth to calcareous material ranges from 8 to 20 inches and thickness of solum ranges from 15 to 40 inches. The weighted average organic carbon content in the upper 15 inches ranges from .1 to .4 percent. The sand/clay ratio ranges from 4 to 18. The 10 to 40 inch control section is typically sandy loam but clay ranges from 5 to 18 percent, silt from 5 to 35 percent, and sand from 5 to 80 percent with more than 35 percent fine sand or coarser and excluding any loamy sand from the above range. The sand is mainly fine and medium and there is less than 25 percent coarse and very coarse sand. Rock fragments range from 0 to 15 percent, but are typically less than 10 percent. Mean annual soil temperature ranges from 47 degrees to 51 degrees F., and mean summer soil temperature ranges from 60 degrees to 68 degrees F.
The A horizon has hue of 2.5Y or 10YR, value of 5 or 6 dry, 4 or 5 moist, and chroma of 2 or 3. It is neutral or mildly alkaline (pH 7.0 to 7.8). The horizon is soft or slightly hard.
The Bk horizon has hue of 2.5Y through 10YR. It is moderately or strongly alkaline (pH 8.0 to 8.6), and has 2 to about 8 percent calcium carbonate equivalent.
COMPETING SERIES: These are the Embudo, Hessing, Koyen, Monue, Quima, and Unionville series. Koyen soils are moderately to strongly alkaline in the solum and has a significant component of volcanic ash and other pyroclastic material. Quima soils have 25 percent or more of coarse or very coarse sand in the 10 to 40 inch section. Unionville soils have bedrock within 40 inches of the surface and are strongly alkaline throughout.
GEOGRAPHIC SETTING: Wall soils are on gently to moderately sloping alluvial fans or valley sideslopes. Slope gradients range from about 1 to 20 percent. The soils formed in alluvial fan sediments derived principally from sandstone. At the type location the average annual precipitation is 7 inches with peak periods of precipitation during the spring and summer months. Mean annual temperature is 44 degrees F. and mean summer temperature is 66 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Apron, Enos, and Saddle soils. Apron soils lack a cambic horizon. Enos soils have an argillic horizon. Saddle soils have an argillic horizon and overlie bedrock.
DRAINAGE AND PERMEABILITY: Well drained; medium or slow runoff; moderate or rapid permeability.
USE AND VEGETATION: These soils are used principally as native pastureland, however, they may be irrigated where water is available. Principal plants are sage, blue grama, cactus, and indian ricegrass.
DISTRIBUTION AND EXTENT: Bain areas of central and northern Wyoming. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Fremont County (Riverton Irrigated Area), Wyoming, 1969.
REMARKS: Diagnostic horizons and features:
Ochric epipedon- the zone from the soil surface to 6 inches (A horizon).
Cambic horizon - the zone from 6 to 28 inches (Bw1 and Bw2 horizons).