LOCATION PORTINO IDEstablished Series
TAXONOMIC CLASS: Coarse-silty, mixed, superactive, mesic Xeric Haplocalcids
TYPICAL PEDON: Portino silt loam, on rangeland, 4 percent slope, east aspect, 4,500 feet elevation. (Colors are for dry soil unless otherwise noted.)
A1--0 to 2 inches; light brownish gray (10YR 6/2) silt loam, dark grayish brown (10YR 4/2) moist; weak thin platy structure parting to weak fine granular; soft, friable, slightly sticky and slightly plastic; common very fine and fine roots; many fine and medium tubular pores; slightly alkaline (pH 7.6); gradual smooth boundary. (1 to 4 inches thick)
A2--2 to 5 inches; pale brown (10YR 6/3) silt loam, dark brown (10YR 4/3) moist; weak medium granular structure; soft, friable, slightly sticky and slightly plastic; common very fine and fine roots; many fine and medium irregular pores; slightly alkaline (pH 7.6); clear wavy boundary. (0 to 5 inches thick)
Bw--5 to 10 inches; pale brown (10YR 6/3) silt loam, brown (10YR 4/3) moist; weak fine subangular blocky structure parting to weak fine granular; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine roots; many fine and medium tubular pores; slightly effervescent; moderately alkaline (pH 8.0); gradual wavy boundary. (4 to 8 inches thick)
Bk1--10 to 19 inches; white (10YR 8/2) silt loam, light brownish gray (10YR 6/2) moist; weak fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine roots; common fine and medium tubular pores; violently effervescent; moderately alkaline (pH 8.4); gradual wavy boundary. (6 to 15 inches thick)
Bk2--19 to 25 inches; light gray (10YR 7/2) silt loam, brown (10YR 5/3) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine roots; many fine and medium tubular pores; violently effervescent; moderately alkaline (pH 8.4); gradual wavy boundary. (5 to 15 inches thick)
Bk3--25 to 28 inches; light gray (10YR 7/2) silt loam, brown (10YR 4/3) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine roots; many fine and medium tubular pores; violently effervescent; moderately alkaline (pH 8.2); abrupt wavy boundary. (0 to 12 inches thick)
2R--28 inches; black (10YR 2/1) hard basalt; common coatings of calcium carbonate on surface and in cracks.
TYPE LOCATION: Bingham County, Idaho; about 4 miles west and 6 miles north of Aberdeen; 2,600 feet east and 150 feet north of the center of sec. 27, T.4S., R.30E.
RANGE IN CHARACTERISTICS:
Depth to bedrock - 20 to 40 inches
Mean annual soil temperature - 47 to 55 degrees F.
Depth to calcic horizon - 6 to 15 inches
Particle-size control section
Clay content - 8 to 18 percent, 5 to 15 percent carbonate clay, 3 to 10 percent carbonate free clay
Fine sand and coarser - 5 to 15 percent
A horizon
Value - 5 or 6 dry, 3 or 4 moist
Chroma - 2 or 3
Reaction - neutral to strongly alkaline
Effervescence - noneffervescent to slightly effervescent
Bw horizon
Value - 5 or 6 dry, 3 or 4 moist
Chroma - 2 or 3
Reaction - neutral to strongly alkaline
Bk horizon
Value - 6 through 8 dry, 4 through 6 moist
Chroma - 1 through 3
Reaction - slightly to strongly alkaline
Effervescence - strong or violent
Calcium carbonate equivalent - 15 to 30 percent
SAR - 2 to 13
COMPETING SERIES: These are the Bahem, Barrymore, Bram, Idahome, Nyssaton, and Pogul series. Bahem, Bram, Idahome, Nyssaton, and Pogul soils are greater than 60 inches deep. In addition, Bram soils are somewhat poorly drained. Barrymore soils have a calcic horizon at 15 to 20 inches.
GEOGRAPHIC SETTING: Portino soils are on loess-mantled lava plains. Slopes range from 0 to 20 percent. They formed in loess and silty alluvium derived from loess and material weathered from basalt. Average annual precipitation ranges from 8 to 11 inches. Average annual temperature ranges from 45 to 53 degrees F. Frost-free season is about 100 to 155 days. Elevation ranges from 3,500 to 4,700 feet.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Kimama, Knull, Minidoka, Portneuf, Rad, Thornock, Trevino, and Vining soils. Kimama soils are greater than 60 inches deep and are fine-silty. Knull soils are greater than 40 inches deep, are fine-silty, and have natric horizons. Minidoka soils have a duripan at 20 to 40 inches. Portneuf soils are greater than 60 inches deep. Rad soils are greater than 60 inches deep and lack calcic horizons. Thornock and Trevino soils are less than 20 inches deep. Vining soils are coarse-loamy and lack calcic horizons. Kimama and Knull soils are in depressional areas on basalt plains. Minidoka soils are on similar landscapes. Portneuf and Rad soils are on similar landscapes but in areas where the deposits overlying the basalt are thicker. Thornock and Trevino soils are on similar landscapes but in areas where the deposits overlying the basalt are thinner. Vining soils are on similar landscapes in areas of sandier parent materials.
DRAINAGE AND PERMEABILITY: Well drained; medium or slow runoff; moderate permeability.
USE AND VEGETATION: This Portino soil is used mainly for irrigated cropland. It is also used for nonirrigated cropland and as rangeland. The potential natural vegetation is mainly bluebunch wheatgrass, Sandberg bluegrass, and Wyoming big sagebrush.
DISTRIBUTION AND EXTENT: Southern Idaho. The series is extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Bingham County, Idaho, 1972.
REMARKS: Diagnostic horizons and other features recognized in this pedon are:
Ochric epipedon
Calcic horizon - the zone from 10 to 28 inches (Bk1, Bk2, and Bk3 horizons).
Some pedons have a thin cambic horizon.
Particle-size control section - the zone from 10 to 28 inches (the Bk1, BK2, and Bk3 horizons)