LOCATION PIERCEPARK IDEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Pachic Argixerolls
TYPICAL PEDON: Piercepark coarse sandy loam -- on a 25 percent slightly concave east-facing slope at 2,950 feet elevation in rangeland. When described on July 26, 1995, the soil was dry to 27 inches and slightly moist below. (Colors are for air-dry soil unless otherwise noted.)
A1--0 to 2 inches; grayish brown (10YR 5/2) coarse sandy loam, very dark brown (10YR 2/2) moist; weak fine granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine and fine, few medium roots; many very fine and fine irregular pores; 10 percent gravel; neutral (pH 6.6); clear smooth boundary.
A2--2 to 6 inches; grayish brown (10YR 5/2) coarse sandy loam, very dark brown (10YR 2/2) moist; weak thin platy structure parting to moderate medium granular; soft, very friable, slightly sticky and slightly plastic; many very fine and fine, few medium roots; many very fine and fine irregular pores; 10 percent gravel; neutral (pH 6.6); clear wavy boundary.
A3--6 to 10 inches; dark grayish brown (10YR 4/2) coarse sandy loam, very dark brown (10YR 2/2) moist; weak fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine and fine, few medium roots; many very fine and fine irregular pores; 10 percent gravel; neutral (pH 6.6); clear wavy boundary. (combined A horizon - 8 to 31 inches thick)
AB--10 to 16 inches; dark grayish brown (10YR 4/2) coarse sandy loam, very dark brown (10YR 2/2) moist; weak fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine and fine roots; common very fine and fine tubular pores; 10 percent gravel; neutral (pH 6.9); clear smooth boundary. (0 to 6 inches thick)
BA--16 to 27 inches; brown (10YR 4/3) coarse sandy loam, very dark grayish brown (10YR 3/2) moist; weak medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine and fine roots; common very fine and fine tubular pores; 10 percent gravel; neutral (pH 7.1); clear wavy boundary. (5 to 14 inches thick)
Bt1--27 to 34 inches; yellowish brown (10YR 5/4) sandy clay loam, dark yellowish brown (10YR 4/4) moist; moderate medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; few very fine, fine and medium roots; common very fine and fine tubular pores; few distinct clay films in pores and bridging sand grains; 10 percent gravel; neutral (pH 7.0); gradual wavy boundary. (6 to 17 inches thick)
Bt2--34 to 60 inches; yellowish brown (10YR 5/4) fine gravelly sandy clay loam, dark yellowish brown (10YR 4/4) moist; moderate fine and medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; few very fine, fine and medium roots; common very fine and fine tubular pores; common distinct clay films on faces of peds, in pores and bridging sand grains; light yellowish brown (10YR 6/4) sandy clay loam lamellae, dark yellowish brown (10YR 4/4) moist, 2 to 12 mm thick and 3 to 5 inches apart; 20 percent gravel; neutral (pH 7.0).
TYPE LOCATION: Ada County, Idaho; about 4.5 miles north and 3.5 miles east of Eagle;250 feet south and 2,600 feet east of the northwest corner of section 30, T.5 N., R.2 E.; USGS Eagle Quadrangle; Latitude - 43 degrees, 44 minutes, 57 seconds N. and Longitude - 116 degrees, 15 minutes, 50 seconds W.; NAD 83.
RANGE IN CHARACTERISTICS:
Thickness of mollic epipedon - 20 to 50 inches
Depth to bedrock - 60 inches or more
Particle-size control section - 18 to 27 percent clay; 25 to 30 percent medium and coarse sand; 10 to 20 percent gravel
Moisture control section - moist less than 90 consecutive days when the soil temperature is greater than 47 degrees F.
Average annual soil temperature - 49 to 53 degrees F.
A horizon
Value - 4 or 5 dry, 2 or 3 moist
Chroma - 2 or 3 dry or moist
Clay content - 10 to 22 percent
Rock fragments - 0 to 15 percent gravel
AB and BA horizons
Value - 4 or 5 dry, 2 or 3 moist
Chroma - 2 or 3 dry or moist
Texture - SL, COSL or L
Clay content - 14 to 24 percent
Rock fragments - 0 to 15 percent gravel
Bt horizon
Value - 5 or 6 dry, 3 or 4 moist
Chroma - 3 or 4 dry or moist
Texture - SCL or COSL
Clay content - 18 to 27 percent
Rock fragments - 10 to 25 percent gravel
Reaction - neutral or slightly alkaline
Lamellae - 0 to 15mm thick
E&Bt horizons may be present in the lower part of some pedons
COMPETING SERIES: These are the Adieux, Banning, Blockhouse , Coolbrith, Deadpan (T), Dotta, Drews, Gorman, Harriman, Haysum, Henhill, Lonkey, Pumphouse (T), Rankor (T), Robinette, Starboard, Supan, Van Dusen, Waha, Wapinitia and Yaxon series. Adieux, Lonkey and Waha soils are 20 to 40 inches deep to a lithic contact. Banning soils are dry for 60 to 90 consecutive days (xeric soil moisture regime) and have redox features in the upper part of the pscs (somewhat poorly drained). Coolbrith soils are somewhat poorly drained and have redoximorphic features in lower part of the profile. Blockhouse soils are moderately well drained, dry for 45 to 60 consecutive days (xeric) and have redoximorphic features in the lower profile. Deadpan soils are not currently in the database and cannot be competed. Dotta soils are 27 to 50 inches deep to the base of the argillic horizon and have a xeric soil moisture regime. Drews soils have 27 to 35 percent clay in the particle-size control section, have a solum 30 to 60 inches thick and mean annual soil temperature of 47 to 50 degrees F. Gorman soils have less than 25 percent medium and coarse sand in the particle-size control section, are moderately acid in the lower part of the soil profile and have a mean annual soil temperature of 57 degrees F. Harriman soils have 27 to 35 percent clay in the particle-size control section, have 2Crk horizons and significant influence from diatomaceous material. Haysum soils have 27 to 35 percent clay in the particle-size control section and have a xeric soil moisture regime. Henhill soils have 27 to 35 percent clay in the particle-size control section, have disseminated lime in the lower part of the profile and are somewhat poorly drained. Pumphouse soils have secondary carbonates (Bk) at a depth of 44 to 60 inches and have a xeric soil moisture regime. Rankor soils are 40 to 60 inches deep to paralithic contact and have a xeric soil moisture regime. Robinette soils have 2Bt horizons that have 40 to 60 percent clay and 60 to 80 percent rock fragments. Starboard soils are 20 to 40 inches to a paralithic contact and have a MAST of 54 to 59 degrees F. Supan soils are 40 to 60 inches deep to a lithic contact. Van Dusen soils have a xeric soil moisture regime and a solum 20 to 48 inches thick. Wapinitia soils contain 27 to 35 percent clay in the particle-size control section and are 40 to 60 inches deep to a lithic contact. Yaxon soils have a solum 24 to 46 inches thick and a xeric soil moisture regime.
GEOGRAPHIC SETTING: Piercepark soils are gently sloping to moderately sloping on fan remnants and hill footslopes at elevations of 2,500 to 4,800 feet. Slopes range from 2 to 25 percent. These soils formed in alluvium from granitic sediments deposited as basin-margin subaqueous deltas and underlying silty lacustrine deposits. The average annual precipitation is 13 to 17 inches. The average annual temperature is 47 to 51 degrees F. The frost-free period is 110 to 150 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cranegulch, Hullsgulch and Quailridge soils. Cranegulch soils contain more than 35 percent clay in the argillic horizon and have mollic epipedons 10 to 20 inches thick. Hullsgulch and Quailridge soils have mollic epipedons that are 10 to 20 inches thick. These soils occur on hill slopes and summits.
DRAINAGE AND PERMEABILITY: Well drained; slow to very rapid runoff; moderate permeability.
USE AND VEGETATION: Piercepark soils are used mainly for rangeland. Native vegetation is bluebunch wheatgrass, Thurber needlegrass, basin big sagebrush and antelope bitterbrush. Some areas are used for irrigated hayland/pasture.
DISTRIBUTION AND EXTENT: West-central Idaho. MLRA 10. Piercepark 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 27 inches (A1, A2, A3, AB and BA horizons)
Argillic horizon - zone from 27 to 60 inches (Bt1 and Bt2 horizons)
Particle-size control section - zone from 27 to 47 inches
Soil moisture regime - aridic bordering on xeric
These soils are drier than other Xerolls in the region under similar precipitation due to early runoff and extended period of high evapotranspiration.