LOCATION ARD ID+WYEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive Calcic Haplocryolls
TYPICAL PEDON: Ard silt loam, cultivated. (Colors are for dry soil unless otherwise noted.)
Ap--0 to 7 inches; dark grayish brown (10YR 4/2 broken, 10YR 5/2 crushed) silt loam, very dark brown (10YR 2/2 broken, 10YR 3/2 crushed) moist; weak very fine granular structure; slightly hard, very friable, slightly sticky and slightly plastic; common fine and very fine roots; common very fine tubular pores; mildly alkaline (pH 7.8); abrupt smooth boundary. (5 to 9 inches thick)
A12--7 to 11 inches; dark grayish brown (10YR 4/2 broken, 10YR 5/2 crushed) silt loam, very dark grayish brown (10YR 3/2) moist; very weak medium and coarse prismatic, parting to weak very fine granular structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine and fine roots; many very fine tubular pores; slightly calcareous; moderately alkaline (pH 8.0); clear smooth boundary. (0 to 6 inches thick)
A13--11 to 16 inches; grayish brown (10YR 5/2) silt loam, very dark grayish brown (10YR 3/2) moist; very weak medium and coarse prismatic, parting to weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine roots; many very fine tubular pores; moderately calcareous; moderately alkaline (pH 8.2); clear wavy boundary. (4 to 8 inches thick)
IIC1ca--16 to 25 inches; light gray (10YR 7/2) loam, grayish brown (10YR 5/2) moist; weak medium and fine subangular blocky structure; hard, friable, slightly sticky and slightly plastic; few very fine and fine roots; common very fine tubular pores; 10 percent 2 to 5 mm. gravel; few 0.3 to 0.5 inch subrounded nodules of soil material; strongly calcareous and common calcium carbonate veins and spots 1 mm. in diameter; rock fragments are coated with calcium carbonate on lower side; strongly alkaline (pH 8.5); clear smooth boundary. (6 to 12 inches thick)
IIC2ca--25 to 32 inches; white (10YR 8/2) channery loam, pale brown (10YR 6/3) moist; massive; hard, friable, slightly sticky and slightly plastic; few fine roots; many very fine tubular pores; common flagstones and flat fragments; strongly calcareous, rock fragments coated with calcium carbonate on lower side; strongly alkaline (pH 8.5); abrupt irregular boundary. (2 to 10 inches thick)
IIR--32 inches; light gray (5YR 7/1) rhyolite or rhyolitic tuff bedrock, gray (5YR 5/1) moist; rock fractures and cracks contain small quantity of strongly calcareous channery loam.
TYPE LOCATION: Teton County, Idaho; about 10 miles west of Felt; 10 feet east of road right-of-way and 1,220 feet north of the southwest corner of section 10, T.6N., R.43E.
RANGE IN CHARACTERISTICS: Depth to bedrock ranges from 20 to 40 inches. The soil between depths of 8 and 24 inches is dry for at least 45 consecutive days during mid and late summer. Mean annual soil temperature is about 38 degrees to 43 degrees F. and the mean summer soil temperature is 55 degrees to 59 degrees F. Rock fragments are common in the profile, but occupy less than 25 percent of any horizon. The soil is mildly or moderately alkaline in the upper part and moderately or strongly alkaline in the lower horizons. The mollic epipedon ranges from 10 to 16 inches in thickness.
The A horizon has value of 4 or 5 dry, 2 or 3 moist, and chroma of 2 or 3. It is usually silt loam ranging to loam, and is slightly gravelly, slightly stony or flaggy. This horizon is mildly or moderately alkaline.
The C horizon immediately below the mollic epipedon is a calcic horizon containing 15 to 30 percent calcium carbonate equivalent. The soil material between depth of 10 inches and the underlying bedrock is medium textured, and has 7 to 18 percent clay, more than 15 percent particles coarser than very fine sand, and less than 35 percent rock fragments.
COMPETING SERIES: These are the Felt, Feltonia, Karlan, Lantonia, Richvale, Ririe, Swanner, and Tetonia series. Felt soils have sand and gravel at depths of 20 to 40 inches. Feltonia, Karlan, Lantonia, Richvale, and Tetonia soils have mollic epipedons thicker than 16 inches. Feltonia, Lantonia, Richvale, Ririe, and Tetonia soils lack bedrock within depth of 40 inches. Swanner soils have bedrock at depths of 10 to 20 inches.
GEOGRAPHIC SETTING: Ard soils are on uplands and have gradients of 1 to 40 percent, dominantly 3 to 9 percent. The soils formed in shallow loessal deposits over and mixed with residuum from rhyolite, rhyolitic tuff, latite, or closely related bedrock. Elevations are 5,500 to 8,000 feet. The cool, subhumid continental climate has warm dry summers and cool, moist winters. Mean annual precipitation is 12 to 17 inches. The mean annual temperature is 36 degrees to 41 degrees F. Frost-free season is about 55 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Karlan, Lantonia, Swanner, and Tetonia soils.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderate permeability.
USE AND VEGETATION: The soils are used primarily for dryland winter wheat. Vegetation is big sagebrush, three-tip sagebrush, bluebunch wheatgrass, junegrass, Nevada bluegrass, and Idaho fescue. DISTRIBUTION AND EXTENT: Southeastern Idaho and western Wyoming. The soils are inextensive.
MLRA OFFICE RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Teton County, Idaho, 1975.