LOCATION FERDINAND ID+WAEstablished Series
TAXONOMIC CLASS: Clayey-skeletal, smectitic, mesic Calcic Argixerolls
TYPICAL PEDON: Ferdinand silt loam - on a 10 percent west-facing slope at 3,140 feet elevation in rangeland. When described on September 2, 1970, the profile was slightly moist below 3 inches. (Colors are for dry soil unless otherwise stated.)
A1--0 to 4 inches; dark grayish brown (10YR 4/2) silt loam, black (10YR 2/1) moist; moderate thin and medium platy structure parting to strong fine granular; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine roots; many very fine tubular pores; about 5 percent basalt gravel; slightly acid (pH 6.2); clear smooth boundary. (1 to 7 inches thick)
A2--4 to 13 inches; dark grayish brown (10YR 4/2) silt loam, black (10YR 2/1) moist; weak medium and coarse subangular blocky structure; hard, friable, slightly sticky and slightly plastic; common very fine, fine and medium roots; many very fine and common medium tubular pores; about 5 percent basalt gravel; neutral (pH 6.8); clear wavy boundary. (0 to 13 inches thick)
Bt--13 to 19 inches; grayish brown (10YR 5/2) very cobbly silty clay loam, very dark gray (10YR 3/1) moist; moderate fine and medium subangular blocky structure; very hard, firm, sticky and plastic; common very fine and fine roots; many very fine tubular pores; many faint clay films on faces of peds and lining pores; faint discontinuous dark grayish brown (10YR 4/2) moist, uncoated silty material on top of this horizon; about 35 percent angular cobbles and 5 percent stones; neutral (pH 6.6); abrupt wavy boundary. (4 to 8 inches thick)
Btk--19 to 32 inches; brown (7.5YR 4/4), (7.5YR 5/4 rubbed) extremely cobbly silty clay, dark yellowish brown (10YR 3/4), (brown 10YR 4/3 rubbed) moist; strong medium and coarse angular blocky structure; very hard, very firm, very sticky and very plastic; few very fine and fine roots; common very fine tubular pores; many very dark grayish brown (10YR 3/2) distinct clay films on faces of peds and lining pores; common slickensides; about 60 percent angular cobbles and 10 percent stones; thin lime coatings on undersides of rock fragments below a depth of 27 inches; (neutral pH 7.0). (9 to 13 inches thick)
R--32 inches; basalt.
TYPE LOCATION: Idaho County, Idaho; about 5.5 miles east of Cottonwood; 990 feet west of southeast corner of sec. 31, T. 32 N., R. 2 E.; Latitude - 46 degrees, 03 minutes, 48 seconds North; Longitude - 116 degrees, 14 minutes, 48 seconds West; USGS - Nezperce SW Quadrangle.
RANGE IN CHARACTERISTICS:
Mollic epipedon thickness - 10 to 20 inches
Depth to bedrock - 20 to 40 inches
Average annual soil temperature - 47 to 51 degrees F.
Soil moisture control section: Dry - July through October Moist - November through June
A horizon
Value - 3 through 5 dry, 2 or 3 moist
Chroma - 1 or 2 dry or moist
Texture of the fine earth fraction - SIL, upper part and SIL or SICL in the lower part
Reaction - slightly acid or neutral
Bt horizon
Hue of 10YR or 7.5YR
Value - 3 through 5 dry, 3 or 4 moist
Chroma - 1 through 4, dry or moist
Texture of fine earth fraction - SICL, SIC, or C
Rock fragments - 35 to 80 percent
Reaction - neutral or mildly alkaline
Btk horizon
Hue - 7.5YR or 10YR
Value - 4 through 8 dry, 3 through 6 moist
Chroma - 2 through 4, dry or moist
Texture of fine earth fraction - CL, SICL, or SIC
Rock fragments - 35 to 80 percent
Reaction - neutral to strongly alkaline
COMPETING SERIES: This is the Degner series. Degner soils are deep to bedrock and have strongly calcareous Ck horizons.
GEOGRAPHIC SETTING: Ferdinand soils are on plateaus and south and west facing slopes in canyons. Slopes range from 0 to 90 percent. The soils formed in loess over residuum weathered from basalt and other fine-grained basic igneous rock at elevations of 2,000 to 4,300 feet. The average annual temperature is 46 to 49 degrees F. and the average annual precipitation is 16 to 24 inches including 2 to 5 feet of snow. Summers are dry. The average frost-free period is 110 to 140 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Fenn, Gwinly, Lawyer, Meland, Nez Perce, Riggins, and Rockly soils. Fenn soils are clayey from the surface and occupy concave positions on plateaus. Gwinly soils are less than 20 inches to bedrock and are on slopes having gradients up to 70 percent. Lawyer soils are very deep and are on steep and very steep north-facing canyon slopes. Meland soils are fine-loamy and are in toeslope position and in concave positions on canyon side slopes. Nez Perce soils are fine-silty and are on undulating hillslopes. Riggins soils are lithic and are on convex areas of canyon side slopes and in areas adjacent to rock outcrop. Rockly soils are lithic and are on steep and very steep south and west-facing slopes.
DRAINAGE AND PERMEABILITY: Well drained; slow to very rapid runoff; permeability is slow.
USE AND VEGETATION: Dry cropland - wheat, peas, barley, hay and pasture. Some areas are used for range and recreation. The potential natural vegetation is mainly Idaho fescue, bluebunch wheatgrass, Sandberg bluegrass, lupine, and arrowleaf balsamroot.
DISTRIBUTION AND EXTENT: West-central Idaho, northeastern Oregon, and southeastern Washington. The series is moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Idaho County, Idaho, 1972.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - the zone from the surface to 19 inches (A1, A2, Bt horizons).
Argillic horizon - the zone from 13 to 32 inches (Bt, Btk horizons).
Accumulation of secondary carbonates - from 19 to 32 inches (Btk horizon)
Particle-size control section - the zone from 13 to 32 inches (Bt, Btk horizon).
Lithic contact - at 32 inches. (R horizon)