LOCATION PICKETPIN IDEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Typic Argixerolls
TYPICAL PEDON: Picketpin loam -- on a convex 34 percent northwest-facing slope at 2,960 feet elevation in rangeland. When described on May 10, 1995, the soil was moist throughout. (Colors are for air-dry soil unless otherwise noted.)
A--0 to 5 inches; grayish brown (10YR 5/2) loam, very dark grayish brown (10YR 3/2) moist; moderate fine granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine and fine, few medium and coarse roots; common very fine and fine tubular pores; 5 percent gravel; neutral (pH 6.8); clear wavy boundary. (4 to 10 inches thick)
Bt1--5 to 11 inches; brown (10YR 5/3) sandy clay loam, dark brown (10YR 3/3) moist; moderate fine and medium subangular blocky structure; hard, very friable, slightly sticky and slightly plastic; many very fine and fine, few medium and coarse roots; common very fine and fine tubular pores; common distinct clay films on faces of peds and in pores; 5 percent gravel; neutral (pH 7.0); gradual wavy boundary. (6 to 10 inches thick)
Bt2--11 to 17 inches; brown (10YR 5/3) clay loam, brown (10YR 4/3) moist; strong medium subangular blocky structure; hard, very friable, moderately sticky and moderately plastic; common very fine and fine, few medium roots; common very fine and fine tubular pores; common distinct clay films on faces of peds and in pores; 10 percent gravel; neutral (pH 7.1); clear smooth boundary. (4 to 14 inches thick)
Bt3--17 to 35 inches; yellowish brown (10YR 5/4) sandy clay loam, dark yellowish brown (10YR 4/4) moist; moderate fine subangular blocky structure; hard, very friable, slightly sticky and slightly plastic; common very fine and fine roots; common very fine and fine tubular pores; few distinct clay films bridging sand grains; discontinuous lamellae 5 to 15mm thick and 1 to 5 inches apart; 10 percent gravel; neutral (pH 7.2); abrupt wavy boundary. (9 to 22 inches thick)
E&Bt--35 to 60 inches; (E material - 80% of horizon) very pale brown (10YR 7/4) fine gravelly coarse sandy loam, light yellowish brown (10YR 6/4) moist; weak fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; few very fine and fine roots; many very fine and fine irregular pores; 30 percent gravel; slightly alkaline (pH 7.4); (Bt material) continuous lamellae, light yellowish brown (10YR 6/4) fine gravelly sandy clay loam, dark yellowish brown (10YR 4/4) moist; 2 to 5mm thick and 10 to 15 inches apart; few distinct clay films bridging sand grains; 25 percent gravel; slightly alkaline (pH 7.4).
TYPE LOCATION: Ada County, Idaho; about 4 miles east and 3 miles north of Eagle; 1,800 feet south and 1,500 feet east of the northwest corner of section 30, T. 5 N., R. 2 E.; USGS Eagle Quadrangle; Latitude - 43 degrees, 44 minutes, 40 seconds N. and Longitude - 116 degrees, 16 minutes, 07 seconds W.; NAD 83.
RANGE IN CHARACTERISTICS:
Thickness of mollic epipedon - 10 to 20 inches
Depth to bedrock - 60 inches or more
Reaction - neutral or slightly alkaline
Moisture control section - dry 60 to 90 consecutive days following the summer solstice
Average annual soil temperature - 48 to 50 degrees F.
A horizon
Value - 4 or 5 dry, 2 or 3 moist
Chroma - 1 through 3 dry or moist
Clay content - 18 to 25 percent
Rock fragments - 0 to 15 percent gravel
Bt horizon
Value - 5 or 6 dry, 3 or 4 moist
Chroma - 2 through 4 dry or moist
Texture - L, CL or SCL
Clay content - 20 to 30 percent
Rock fragments - 5 to 15 percent gravel
Lamellae (lower part) - 0 to 25mm thick and 1 to 5 inches apart
E&Bt horizon
Clay content (weighted average) - 10 to 20 percent
Rock fragments (weighted average) - 15 to 35 percent gravel
-E material (75 to 90 percent)
Value - 6 through 8 dry, 5 or 6 moist
Chroma - 3 or 4 dry or moist
Texture - SL, COSL or LCOS
-Bt material (lamellae)
Thickness - 2 to 5mm
Separation - 7 to 15 inches
COMPETING SERIES: These are the Ahsahka, Canyonspring (T), Colma, Currymountain, Dragnot, Duzel, Elkheights (T), Facey, Farrot, Foehlin, Hatspring (T), Immiant, Ladd, Lobitos, Mehlhorn, Pittville, Sagaser, Taneum, Tieton, Tweedy, and Vollmer and Yardarm series. Ahsahka soils have 2Bt horizons with 32 to 50 percent clay and slickensides, and have Oi horizons. Colma soils have mottled B horizons overlying slowly or very slowly permeable C horizons and have a mean annual soil temperature of 55 to 58 degrees F. Canyonspring soils are not currently in the database and cannot be competed. Currymountain, Duzel and Tweedy soils are 20 to 40 inches deep to a paralithic contact. Dragnot, Farrot, Hatspring, Immiant, Lobitos, Mehlhorn and Vollmer soils are 20 to 40 inches deep to lithic contact. Elkheights soils have Cd horizons and are dry for 75 to 90 consecutive days. Facey and Taneum soils are 40 to 60 inches deep to a lithic contact. Foehlin soils have average annual soil temperatures of 52 to 56 degrees F. and do not have lamellae in the Bt horizon. Ladd soils have high amounts of volcanic ash in the soil surface, do not have lamellae in the argillic horizon and are dry for 80 to 90 consecutive days in the summer. Pittville soils have average annual soil temperatures of 52 to 54 degrees F. Sagaser soils are 40 to 60 inches deep to a paralithic contact. Tieton soils are 40 to 60 inches deep to a lithic contact and have calcareous C horizons. Yardarm soils are 20 to 40 inches to a paralithic contact (schist) and have a MAST of 54 to 59 degrees F.
GEOGRAPHIC SETTING: Picketpin soils are steep to very steep on north-facing hill backslopes at elevations of 2,650 to 4,450 feet. These soils formed in mixed colluvium and alluvium from granitic sediments deposited as basin-margin subaqueous deltas and underlying silty lacustrine deposits. Slopes range from 25 to 65 percent. The average annual precipitation is 14 to 20 inches. The average annual temperature is 46 to 48 degrees F. The frost-free period is 100 to 120 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ayette, Hann, Quailridge and Van Dusen soils. Ayette soils are 40 to 60 inches deep to paralithic contact, fine textured and are on similar geomorphic positions. Hann soils are pachic, fine textured and on concave hill backslopes and footslopes. Quailridge soils have an aridic bordering on xeric soil moisture regime and are on hill summits. Van Dusen soils are pachic and occur on similar geomorphic positions.
DRAINAGE AND PERMEABILITY: Well drained; medium to very rapid runoff; moderate permeability.
USE AND VEGETATION: Picketpin soils are used mainly for rangeland. Native vegetation is Idaho fescue, bluebunch wheatgrass and xeric big sagebrush.
DISTRIBUTION AND EXTENT: West-central Idaho. MLRA 10. Picketpin soils are of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Boise County Area, Idaho, Parts of Ada and Boise Counties, 2005.
REMARKS: Diagnostic horizons and features recognized in this pedon:
Mollic epipedon - zone from the surface to 11 inches (A and Bt1 horizons)
Argillic horizon - zone from 5 to 35 inches (Bt1, Bt2 and Bt3 horizons)
Particle-size control section - zone from 5 to 25 inches
Soil moisture regime - xeric