LOCATION CARTWRIGHT IDEstablished Series
The Cartwright series consists of very deep, well drained soils with moderate permeability that formed in colluvium and alluvium from granitic rocks. Slopes range from 3 to 65 percent in foothills, canyons and valleys. The average annual precipitation is about 18 inches and the average annual temperature is about 47 degrees F.
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Pachic Ultic Argixerolls
TYPICAL PEDON: Cartwright loam -- on a 33 percent concave northwest-facing slope at 4,200 feet elevation in rangeland. When described on July 20, 1994, the soil was dry to 42 inches and slightly moist below. (Colors are for air-dry soil unless otherwise noted.)
A1--0 to 2 inches; dark grayish brown (10YR 4/2) 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 and coarse roots; many very fine and fine irregular pores; 5 percent fine gravel; slightly acid (pH 6.4); clear smooth boundary. (2 to 4 inches thick)
A2--2 to 8 inches; dark grayish brown (10YR 4/2) loam, very dark brown (10YR 2/2) moist; moderate fine platy structure parting to moderate fine granular; slightly hard, very friable, slightly sticky and slightly plastic; common very fine and fine, few medium and coarse roots; common very fine and fine tubular pores; 5 percent fine gravel; slightly acid (pH 6.5); clear wavy boundary. (2 to 11 inches thick)
A3--8 to 21 inches; brown (10YR 5/3) loam, dark brown (10YR 3/3) moist; weak fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine and fine, few medium and coarse roots; common very fine and fine tubular pores; 5 percent fine gravel; neutral (pH 6.6); clear wavy boundary. (5 to 14 inches thick)
BA--21 to 33 inches; brown (10YR 5/3) loam, brown (10YR 4/3) moist; moderate fine and medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; few very fine, fine and medium roots; many very fine and tubular pores; 5 percent fine gravel; slightly acid (pH 6.5); gradual wavy boundary. (8 to 17 inches thick)
Bt1--33 to 48 inches; brown (10YR 5/3) loam, brown (10YR 4/3) moist; moderate medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; few very fine and fine roots; many very fine and fine tubular pores; few distinct clay films on faces of peds and in pores; 5 percent fine gravel; slightly acid (pH 6.4); clear wavy boundary. (12 to 22 inches thick)
Bt2--48 to 60 inches; pale brown (10YR 6/3) loam, brown (10YR 4/3) moist; moderate fine and medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; few very fine and fine roots; common very fine and fine tubular pores; common faint clay films on faces of peds and in pores; 10 percent fine gravel; slightly acid (pH 6.4).
TYPE LOCATION: Boise County, Idaho; about 9 miles south and 1 mile west of Horseshoe Bend; 350 feet north and 500 feet west of the southeast corner of section 9, T.5 N., R.2 E.; USGS Cartwright Canyon Quadrangle; Latitude - 43 degrees, 46 minutes, 45 seconds N. and Longitude - 116 degrees, 12 minutes, 57 seconds W.; NAD 83.
RANGE IN CHARACTERISTICS:
Mollic epipedon thickness - 20 to 46 inches
Depth to bedrock - 60 inches or more
Reaction - slightly acid or neutral
Base saturation - 50 to 75 percent in some part of the upper 30 inches
Rock fragments - dominantly fine gravel
Moisture control section - dry 60 to 90 consecutive days following the summer solstice
Average annual soil temperature - 47 to 52 degrees F.
A horizon
Value - 4 or 5 dry, 2 or 3 moist
Chroma - 2 or 3 dry or moist
Clay content - 15 to 18 percent
Rock fragments - 0 to 15 percent gravel
BA horizon
Value - 4 or 5 dry, 3 or 4 moist
Chroma - 2 through 4 dry or moist
Texture - L, SL or COSL
Clay content - 15 to 18 percent
Rock fragments - 0 to 25 percent gravel
Bt horizon
Value - 5 through 7 dry, 4 or 5 moist
Chroma - 3 or 4 dry or moist
Texture - L, CL or SCL
Clay content - 18 to 30 percent
Rock fragments - 5 to 35 percent gravel
COMPETING SERIES: These are the Buckeye, Campfour, Elmore, Hyprairie, Kiakus, Lauby, Newlig, Nisene, Paragon, Roseburg, Rudo (I), Swalecreek (T) and Yaxing (T) soils. Paragon soils are moderately deep to a paralithic contact. Buckeye soils do not have an activity class family designated, but are moderately deep to a lithic contact. Kiakus soils are moderately deep to a lithic contact. Campfour soils are forested, have O horizons and color hue of 2.5YR through 7.5YR. Elmore soils are deep to bedrock. Hyprairie soils have upper solums dominated by loess over 2Bt horizons and rock fragments within the argillic horizon not of granitic origin. Lauby soils have buried Bt horizons, are forested with O horizons, and are dry for 45 to 60 consecutive days. Newlig soils formed in sediments and have less than 5 percent rock fragments throughout. Nisene soils are 40 to 60 inches to a paralithic contact and have average annual soil temperatures of 56 to 58 degrees F. Rudo soils have a paralithic contact at 40 to 60 inches. Roseburg soils have average annual soil temperatures of 52 to 57 degrees F.and have redoximorphic features below 40 inches. Swalecreek soils have Btc horizons with hard manganese concretions and rock fragments not of granitic origin. Yaxing soils are forested and slightly alkaline below the surface layer.
GEOGRAPHIC SETTING: Cartwright soils are on fan remnants, canyon walls and hill footslopes and backslopes at elevations of 2,500 to 5,600 feet. Slopes range from 3 to 65 percent. These soils formed in colluvium and alluvium from granitic rocks. The average annual precipitation is 14 to 22 inches. The average annual temperature is 45 to 50 degrees F. The frost-free season is 90 to 140 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Brownlee, Robbscreek, Roney and Schiller soils. Brownlee soils are deep and occur on convex north-facing slopes. Robbscreek soils are moderately deep and occur on convex south-facing slopes. Roney soils are moderately deep, do not have Bt horizons and occur on convex foothills. Schiller soils are very deep and occur on over-steepened hill footslopes.
DRAINAGE AND PERMEABILITY: Well drained; slow to rapid runoff; moderate permeability.
USE AND VEGETATION: Cartwright soils are used mainly for rangeland. Small areas are used for irrigated hayland/pasture. Native vegetation is Idaho fescue, bluebunch wheatgrass and xeric big sagebrush.
DISTRIBUTION AND EXTENT: West-central Idaho. MLRA 10. Cartwright 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 21 inches (A1, A2, and A3 horizons)
Argillic horizon - zone from 33 to 60 inches ( Bt1 and Bt2 horizons)
Particle-size control section - zone from 33 to 53 inches
Soil moisture regime xeric