LOCATION KARLAN ID+WYEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive Calcic Pachic Haplocryolls
TYPICAL PEDONS: Karlan silt loam, cultivated. (Colors are for dry soil unless otherwise noted)
Ap--0 to 8 inches; dark grayish brown (10YR 4/2) silt loam, very dark brown (10YR 2/2) moist; weak fine and very fine granular structure; slightly hard, very friable, slightly sticky and slightly plastic; few fine roots; common very fine pores; few angular pebbles; slightly acid (pH 6.2); abrupt smooth boundary. (5 to 9 inches thick)
A11--8 to 15 inches; dark grayish brown (10YR 4/2) silt loam, very dark brown (10YR 2/2) moist; weak coarse prismatic parting to very weak coarse subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; few fine roots; common very fine tubular and interstitial pores; less than 5 percent angular gravel; slightly acid (pH 6.5); clear smooth boundary. (3 to 8 inches thick)
A12--15 to 18 inches; dark grayish brown (10YR 4/2) silt loam, very dark brown (10YR 2/2) moist; weak coarse prismatic parting to weak coarse and medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; few fine roots; common very fine tubular and interstitial pores; less than 5 percent angular gravel; slightly more coarse sand and fine gravel than in A11 horizon; few thin clay films on vertical and horizontal surfaces of peds and in pores; neutral (pH 6.6); clear smooth boundary. (2 to 5 inches thick)
B2--18 to 26 inches; brown (10YR 5/3) gravelly silt loam, dark brown (10YR 3/3) moist; very weak coarse prismatic parting to weak coarse subangular blocky structure; hard, friable, slightly sticky and slightly plastic; few fine roots; common very fine tubular and interstitial pores; few thin clay films on vertical and horizontal surfaces of peds and in pores; less than 5 percent angular gravel; neutral (pH 6.7); abrupt irregular boundary. (6 to 12 inches thick)
Cca--26 to 32 inches; light gray (10YR 7/2) extremely stony loam, pale brown (10YR 6/3) moist; massive; hard, friable, slightly sticky and slightly plastic; few very fine tubular pores; strongly calcareous; mildly alkaline (pH 7.8); abrupt irregular boundary. About 85 percent of the mass is lime-coated rhyolitic tuff fragments. (0 to 8 inches thick)
R--32 inches; light gray (5YR 7/2) rhyolitic tuff bedrock, gray (5YR 5/1) moist; absorbs water readily.
TYPE LOCATION: Teton County, Idaho; about 11.6 miles west of Tetonia; 880 feet west and 650 feet north of the SE corner SW1/4 of section 28, T.6N., R.43E.
RANGE IN CHARACTERISTICS: Depth to bedrock is 20 to 40 inches. Mean annual soil temperature is about 38 degrees to 43 degrees F. and the mean summer soil temperature at a depth of 20 inches is about 56 degrees to 59 degrees F. The mollic epipdon ranges from 16 to 32 inches thick. The solum includes up to 20 percent rock fragments by volume, and ranges from medium acid to neutral. Between depths of 10 inches and the underlying bedrock, the soil contains between 18 and 27 percent clay and more than 15 percent fine sand or coarser, and averages 5 to 20 percent rock fragments.
The A horizon has value of 3 or 4 dry, 2 or 3 moist, and chroma of 2 or 3 moist and dry. This horizon is commonly silt loam, but includes few angular pebbles or channery fragments, angular cobblestones or flagstones, and/or stones. Reaction is neutral or mildly alkaline.
The B2 horizon has value of 4 or 5 dry and 2 or 3 moist, and chroma of 2 or 3 moist and dry. Clay increases over the A horizon ranges from 0 to 2.5 percent. This horizon is commonly silt loam but ranges to loam. Weak or moderate bleacbed silty coatings and weak organic stains are present on the peds in some pedons. Reaction is neutral or mildly alkaline.
COMPETING SERIES: These are the Adel, Bullrey (t) Gallatin, Idmon (t), Lamphier, Leavittville, Nundos, Osmund, Pavohroo, and Winevada series. Adel, Bullrey, and Pavohroo soils are deeper than 40 inches to bedrock and lack strong lime accumulations. Gallatin, Idmon, Kennally, and Lamphier soils are deeper than 40 inches to sand and gravel, and lack B horizons. Leavittville, Mundos, and Osmund soils lack bedrock within depth of 60 inches. Winevada soils lack Cca horizons.
GEOGRAPHIC SETTING: Karlan soils are on uplands and have gradients of 0 to 40 percent. The soils formed in thin loess over residuum from rhyolite or rhyolitic tuff. Elevations are 5,500 to 7,000 feet. The climate is subhumid continental which is relatively dry in mid- and late summer with cool, moist winters. Mean annual precipitation is 15 to 18 inches. The mean annual temperature is 36 to 41 degrees F. Frost-free season is about 50 to 80 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ard, Greys, and Swanner soils. Ard soils have mollic epipedons less than 16 inches thick and average less than 18 percent clay between depth of 10 inches and the underlying bedrock. Greys soils have argillic horizons. Swanner soils have a lithic contact above depth of 20 inches.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderate permeability.
USE AND VEGETATION: Most areas are cultivated for production of wheat, oats, barley, alfalfa and grass hay. Some areas are used for range. Vegetation is mainly bluebunch wheatgrass Idaho fescue, junegrass Columbia needlegrass, big bluegrass, Sandberg bluegrass, big sagebrush, three-tip sagebrush, bitterbrush, balsomroot, yarrow, and low buckwheat.
DISTRIBUTION AND EXTENT: Southeastern Idaho. The soils are extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Teton County, Idaho, 1975.
OSED scanned by SSQA. Last revised by state on 11/75.