LOCATION MCCAIN IDEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Petronodic Xeric Calciargids
TYPICAL PEDON: McCain silt loam, rangeland. (Colors are for air-dry soil unless otherwise stated.)
A--0 to 2 inches; brown (10YR 5/3) silt loam, dark grayish brown (10YR 4/2) moist; moderate fine granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine and fine roots; many fine irregular pores; neutral (pH 6.6); clear smooth boundary. (2 to 4 inches thick)
E--2 to 7 inches; pale brown (10YR 6/3) silt loam, brown (10YR 4/3) moist; moderate thin platy structure; soft, very friable, slightly sticky and slightly plastic; common fine roots; many fine vesicular pores; neutral (pH 7.2); abrupt smooth boundary. (0 to 5 inches thick)
Bt1--7 to 12 inches; brown (10YR 5/3) silty clay loam, brown (10YR 4/3) moist, yellowish brown (10YR 5/4) moist, crushed; weak medium prismatic structure parting to moderate fine and medium subangular blocky; hard, firm, moderately sticky and moderately plastic; common fine and medium roots; many fine tubular pores; many faint clay films on faces of peds; moderately alkaline (pH 8.3); clear smooth boundary. (2 to 9 inches thick)
Bt2--12 to 16 inches; very pale brown (10YR 7/3) silt loam, brown (10YR 5/3) moist; weak medium prismatic structure parting to moderate fine and medium subangular blocky; hard, firm, moderately sticky and moderately plastic; common fine and medium roots; many fine tubular pores; many faint clay films on faces of peds; moderately alkaline (pH 8.3); gradual wavy boundary. (3 to 7 inches thick)
Btk--16 to 22 inches; very pale brown (10YR 7/3) silt loam, pale brown (10YR 6/3) moist; weak fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few fine roots; many fine tubular pores; few faint clay films on faces of peds; common fine lime veins between peds; slightly effervescent; moderately alkaline (pH 8.2); clear smooth boundary. (0 to 6 inches thick)
Bk1--22 to 29 inches; white (10YR 8/2) loam, very pale brown (10YR 7/3) moist; massive; slightly hard, firm, nonsticky and slightly plastic; 10 percent gravel; 25 percent strongly cemented cicada nodules; strongly effervescent; moderately alkaline (pH 8.0); gradual smooth boundary. (6 to 9 inches thick)
Bk2--29 to 33 inches; light gray (10YR 7/2) loam, pale brown (10YR 6/3) moist; massive; slightly hard, friable, nonsticky and slightly plastic; 5 percent gravel; 25 percent strongly cemented cicada nodules; strongly effervescent; moderately alkaline (pH 8.0); abrupt wavy boundary. (0 to 5 inches thick)
2R--33 inches; basalt; lime-coated on upper surface and in fractures.
TYPE LOCATION: Ada County, Idaho; about 3 miles south of Kuna, Idaho, about 1,950 feet south and 1,500 feet west from the northeast corner of section 20, T. 1N., R. 1W.
Latitude - 43 degrees, 24 minutes, 38 seconds North; Longitude - 116 degrees, 28 minutes, 48 seconds West.
RANGE IN CHARACTERISTICS:
Depth to bedrock - 20 to 40 inches
Depth to the calcic horizon is 12 to 25 inches
Control section
Total clay content - 18 to 30 percent
Carbonate clay (estimated) - 0 to 5 percent, carbonate free clay 18 to 25 percent
Weighted average has 5 to 15 percent particles of fine sand through gravel (0.1 to 75 mm)
Average annual soil temperature - 47 to 56 degrees F.
The soil moisture control section is dry for one-half to three-fourths of the time when the soil temperature is above 41 degrees F.
A horizon
Value - 5 or 6 dry, 3 or 4 moist
Chroma - 2 or 3 dry or moist
Reaction - neutral or slightly alkaline
E horizon
Value - 6 or 7 dry
Chroma - 2 or 3 dry or moist
Texture - SIL, L, STX-SIL, STV-SIL
Gravel - 0 to 10 percent
Cobbles - 0 to 5 percent
Stones - 0 to 15 percent
Bt horizon
Value - 4 through 7 dry, 4 or 5 moist
Chroma - 3 or 4 dry or moist
Texture - SIL, SICL, CL, ST-SICL
Reaction - slightly or moderately alkaline
Gravel - 0 to 10 percent
Cobbles - 0 to 5 percent
Stones - 0 to 15
Bk horizon
Value 6 through 8 dry, 4 through 7 moist
Chroma 2 to 4 moist or dry
Gravel - 0 to 10 percent
Cobbles - 0 to 20 percent
Texture - L, SIL, CB-SIL
Reaction - slightly through strongly alkaline
Nodules - 20 to 40 percent
Calcium carbonate equivalent - 15 to 30 percent
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: McCain soils are on basalt plains and terraces. Slopes range from 0 to 20 percent. The soil formed in loess or silty alluvium from mixed sources. Elevation ranges from 2,500 to 4,700 feet. The mean annual precipitation is about 8 to 12 inches. The mean annual air temperature is about 45 to 52 degrees F. The frost-free period is 100 to 160 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Chilcott, Elijah, Power and Trevino soils. Chilcott and Elijah soils are moderately deep to a duripan. Power soils are very deep. Trevino soils are shallow to bedrock. All these soils occur on basalt plains.
DRAINAGE AND PERMEABILITY: Well drained; very slow to very rapid runoff; moderately slow permeability.
USE AND VEGETATION: McCain soils are used for irrigated cropland, pastureland and rangeland. The principal crops grown are sugar beets potatoes, corn, corn silage, dry beans and alfalfa hay. The native vegetation is Wyoming big sagebrush and bluebunch wheatgrass.
DISTRIBUTION AND EXTENT: Southern Idaho. This series is moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Lincoln County, Idaho, 1943.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from the soil surface to 7 inches (A and E horizons)
Argillic horizon - the zone from 7 to 22 inches (Bt1, Bt2 and Btk horizons)
Calcic horizon - the zone from 22 to 33 inches (Bk1 and Bk2 horizons)
Petronodic - over 20 percent nodules from 22 to 33 inches
Particle-size control section - the zone from 7 to 22 inches (Bt1, Bt2 and Btk horizons)