LOCATION RIEDEL MTEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, calcareous, frigid Aridic Ustorthents
TYPICAL PEDON: Riedel fine sandy loam, grassland. (Colors are for dry soil unless otherwise noted.)
A1--0 to 5 inches; grayish brown (10YR 5/2) fine sandy loam, dark grayish brown (10YR 4/2) moist; weak medium and fine granular structure; soft, very friable, nonsticky and nonplastic; many medium and fine roots; slightly effervescent; mildly alkaline; gradual wavy boundary. (2 to 6 inches thick)
C1--5 to 17 inches; light yellowish brown (10YR 7/3) fine sandy loam, light olive brown (10YR 5/3) moist; weak coarse prismatic structure; soft, very friable, nonsticky and nonplastic; common medium and fine roots; strongly effervescent; few soft masses of segregated lime; moderately alkaline; clear wavy boundary. (5 to 18 inches thick)
C2--17 to 24 inches; light yellowish brown (10YR 6/4) soft sandstone which crushes to loamy very fine sand, yellowish brown (10YR 5/4) moist; platy rock structure; common fine roots vertical cracks and through the plates and along the horizontal bedding planes; slightly effervescent.
C3r--24 to 60 inches; light yellowish brown (10YR 6/4) soft sandstone; platelike; few roots in vertical cracks; slightly effervescent.
TYPE LOCATION: Blaine County, Montana; about 2540 feet south and 1840 feet west of the NE corner of section 34, T.26N., R.20E.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 40 to 47 degrees F. The depth to soft sedimentary beds ranges from 7 to 20 inches. Color hues are 10YR or 2.5Y.
The A horizon has value of 5 or 6 dry, 4 or 5 moist, and chroma of 2 or 3. It is mildly or moderately alkaline, and is slightly or strongly effervescent.
The upper C horizons have value of 5 through 7 dry, 4 through 6 moist, and chroma of 2 through 4. They are is mildly or moderately alkaline and are strongly or violently effervescent.
The lower C horizon is soft sedimentary beds that are mainly soft sandstone that retains rock structure but has roots in cracks and between and through plates. This horizon is partially root-limiting and has common roots in the upper part and few below depths of 24 to 30 inches. Some pedons have lenses of harder rock but have fractures which roots go through and develop in the underlying softer material.
COMPETING SERIES: These are the Blackhall, Blazon, Byrnie, Cabbart, Seaverson, Shinbara and Thermopolis series. Blackhall soils have a paralithic contact that doesn't allow roots to enter the underlying rock and in addition have a growing season of less than 90 days. Blazon, Cabbart, Seaverson and Shinbara soils have more than 18 percent clay in the control section. Also, Shinbara soils are 2 to 10 inches deep to sedimentary beds. Byrnie and Thermopolis soils have hue of 5YR through 10YR.
GEOGRAPHIC SETTING: Riedel soils are moderately sloping to steep and are on uplands at elevations of 2,500 to 4,500 feet. They formed in material weathered from soft sandstone sedimentary beds. The climate is cool, dry-semiarid, continental, with long cold winters and moist springs. The mean annual precipitation is 10 to 14 inches, most of which falls in spring or early summer. The mean annual temperature is 41 to 46 degrees F. The (32 degree F.) growing season is 105 to 125 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are Busby, Delpoint, Twilight, and the competing Cabbart soils. Busby soils are deep and are mainly on the alluvial fans. Delpoint and Twilight soils have sedimentary beds at depths of 20 to 40 inches and are on ridges and hillsides. Cabbart soils are on similar positions in the landscape.
DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff; moderate permeability.
USE AND VEGETATION: These soils are used mainly for range, but small areas are used for dryland farming. The native vegetation is mainly needleandthread, western wheatgrass, prairie junegrass, blue grama, threadleaf sedge, and some forbs and shrubs.
DISTRIBUTION AND EXTENT: Central and eastern Montana. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Blaine County, Montana, 1976.
OSED scanned by SSQA. Last revised by state on 11/76.