LOCATION PUMPKIN ID+WYEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Pachic Ultic Argixerolls
TYPICAL PEDON: Pumpkin stony loam, forested - on a south-facing slope of 12 percent at 5,480 feet elevation. When described on October 26, 1994, the soil was slightly moist to 8 inches and dry below. (Colors are for air-dry soil unless otherwise noted.)
Oi--0 to 1 inch; slightly decomposed forest litter.
A--1 to 3 inches; dark grayish brown (10YR 4/2) stony loam, very dark grayish brown (10YR 3/2) moist; moderate thin and medium platy structure; soft, very friable, slightly sticky and slightly plastic; many very fine, fine and medium, few coarse roots; many very fine, fine and medium irregular pores; 5 percent stones, 5 percent cobbles, 10 percent gravel; moderately acid (pH 5.7); clear smooth boundary. (2 to 4 inches thick)
AB--3 to 9 inches; dark grayish brown (10YR 4/2) stony loam, very dark grayish brown (10YR 3/2) moist; weak fine subangular blocky structure parting to moderate medium granular; soft, very friable, slightly sticky and slightly plastic; many very fine, fine and medium, few coarse roots; many very fine, fine and medium irregular pores; 5 percent stones, 5 percent cobbles, 10 percent gravel; moderately acid (pH 5.7); clear wavy boundary. (5 to 10 inches thick)
Bt1--9 to 14 inches; dark grayish brown (10YR 4/2) gravelly clay loam, dark brown (10YR 3/3) moist; moderate fine angular blocky structure; hard, firm, moderately sticky and moderately plastic; many very fine, fine and medium, few coarse roots; many very fine, fine and medium tubular pores; many distinct clay films on faces of peds and in pores; 5 percent cobbles, 15 percent gravel; moderately acid (pH 5.7); clear wavy boundary. (5 to 12 inches thick)
Bt2--14 to 22 inches; olive brown (2.5Y 4/4) very gravelly loam, dark olive brown (2.5Y 3/3) moist; moderate fine and medium subangular blocky structure; hard, firm, moderately sticky and moderately plastic; common very fine and fine, few medium and coarse roots; many very fine, fine and medium tubular pores; many distinct clay films on faces of peds and in pores; 5 percent stones, 5 percent cobbles, 45 percent gravel; moderately acid (pH 5.7); gradual wavy boundary. (4 to 14 inches thick)
BCt--22 to 44 inches; light olive brown (2.5Y 5/4) extremely gravelly sandy loam, olive brown (2.5Y 4/3) moist; weak fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine, few medium and coarse roots; many very fine, fine and medium tubular pores; common distinct clay films on faces of peds and in pores; 5 percent stones, 5 percent cobbles, 50 percent gravel; moderately acid (pH 5.8); gradual wavy boundary. (0 to 12 inches thick)
C--44 to 60 inches; olive brown (2.5Y 4/4) extremely gravelly sandy loam, very dark grayish brown (2.5Y 3/2) moist; massive; soft, very friable, nonsticky and slightly plastic; common very fine and fine, few medium and coarse roots; many very fine, fine and medium tubular pores; 5 percent stones, 10 percent cobbles, 60 percent gravel; moderately acid (pH 6.0).
TYPE LOCATION: Boise County, Idaho; about 4 miles south and 3 miles east of Banks; 1,800 feet south and 1,100 feet east of the northwest corner of section 23, T.8 N., R.3 E.; Latitude - 44 degrees, 01 minute, 06 seconds N. and Longitude - 116 degrees, 04 minutes, 27 seconds W.; NAD 83.
RANGE IN CHARACTERISTICS:
Mollic epipedon thickness - 20 to 50 inches
Depth to bedrock - greater than 60 inches
Depth to the base of the argillic horizon - 20 to 40 inches
Base saturation (10 to 30 inches) - 50 to 75 percent
Reaction - strongly acid or moderately acid
Particle-size control section - 25 to 35 percent clay; 35 to 50 percent rock fragments
Moisture control section - dry 45 to 75 consecutive days following the summer solstice
Average annual soil temperature - 43 to 47 degrees F.
A horizon
Value - 3 or 4 dry, 2 or 3 moist
Chroma - 2 or 3 dry or moist
Clay content - 18 to 25 percent
Rock fragments - 5 to 15 percent gravel, 0 to 15 percent cobbles, 0 to 10 percent stones and 15 to 35 percent total
Bt1 horizon
Value - 3 or 4 dry, 2 or 3 moist
Chroma - 2 or 3 dry or moist
Texture - CL or L
Clay content - 25 to 30 percent
Rock fragments - 10 to 30 percent gravel, 5 to 10 percent cobbles, 0 to 5 percent stones and 15 to 35 percent total
Bt2 horizon
Hue - 2.5Y or 10YR
Value - 4 or 5 dry
Chroma - 2 through 4 dry or moist
Texture - CL or L
Clay content - 25 to 35 percent
Rock fragments - 20 to 50 percent gravel, 5 to 25 percent cobbles, 0 to 5 percent stones and 35 to 60 percent total
C horizon
Hue - 2.5Y or 10YR
Value - 4 or 5 dry
Chroma - 2 through 4 dry or moist
Clay content - 10 to 15 percent
Rock fragments - 45 to 70 percent gravel, 5 to 15 percent cobbles, 0 to 10 percent stones and 60 to 80 percent total
COMPETING SERIES: These are the Benhall (T), Greystoke, Jumbo, Moreglade, Sherval, Smarts and Toncana series. Benhall soils are 30 to 40 inches deep to paralithic contact. Greystoke and Jumbo soils are 40 to 60 inches deep to paralithic contact. Moreglade soils do not have O horizons and have an argillic horizon with a lower boundary below 40 inches. Sherval soils have a lithologic discontinuity between 24 and 60 inches and are dry for more than 90 consecutive days following the summer solstice. Smarts soils have an argillic horizon with a lower boundary below 40 inches and 35 to 85 percent rock fragments in the PSCS of sandstone or quartzite origin. Toncana soils have hues of 2.5YR through 7.5YR in the Bt horizons, an argillic horizon with a lower boundary below 40 inches and 35 to 60 percent rounded rock fragments of quartzite origin.
GEOGRAPHIC SETTING: Pumpkin soils are on stream terraces, hill toeslopes and structural benches at elevations of 3,650 to 5,850 feet. These soils formed in colluvium and alluvium from basalt and fine pyroclastic materials. Slopes range from 8 to 25 percent. The average annual precipitation is 24 to 34 inches. The average annual temperature is 41 to 45 degrees F. The frost-free period is 60 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cleymor, Highvalley and Shilling soils. Cleymor soils are fine textured and on similar geomorphic positions. Highvalley soils are fine-loamy and have vitrandic features. Shilling soils have a mollic epipedon less than 20 inches thick and vitrandic features. Highvalley and Shilling soils are on steeper slopes.
DRAINAGE AND PERMEABILITY: Well drained; rapid runoff; moderately slow permeability.
USE AND VEGETATION: Pumpkin soils are used mainly for timber production and woodland grazing. Native vegetation is ponderosa pine, Douglas-fir and mallow ninebark.
DISTRIBUTION AND EXTENT: West-central Idaho. MLRA 43b. Pumpkin soils are not extensive.
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 soil:
Mollic epipedon - zone from the mineral soil surface to 22 inches (A, AB, Bt1 and Bt2 horizons)
Argillic horizon - zone from 9 to 22 inches (Bt1 and Bt2 horizons)
Particle-size control section - zone from 9 to 22 inches
Soil moisture regime - xeric
All depths to diagnostic horizons and features within the range of characteristics are measured from the top of the first mineral horizon.