LOCATION IDAHOME IDEstablished Series
The Idahome series consists of very deep, well drained, moderately
permeable, saline soils on fan and high stream terraces. They formed
in silty alluvium. Slopes are 0 to 4 percent. The average annual
precipitation is about 10 inches and the average annual temperature is
about 46 degrees F.
TAXONOMIC CLASS: Coarse-silty, mixed, superactive, mesic Xeric Haplocalcids
TYPICAL PEDON: Idahome silt loam -- rangeland. On a 2 percent single
slope, northeast aspect, 5,200 feet elevation. (When described June
22, 1982 the soil was dry to 10 inches and moist below. Colors are for
dry soil unless otherwise noted.)
A1--0 to 2 inches; pale brown (10YR 6/3) silt loam, brown (10YR
4/3) moist; moderate very thick platy structure; slightly hard and very
friable; few very fine roots; many very fine and common fine and medium
vesicular pores; slightly effervescent (4 percent calcium carbonate
equivalent); moderately alkaline (pH 8.2); abrupt smooth boundary. (1
to 4 inches thick)
A2--2 to 5 inches; pale brown (10YR 6/3) silt loam, brown (10YR
4/3) moist; weak very thick platy structure parting to weak fine
subangular blocky; slightly hard and very friable; many very fine
roots; many very fine vesicular pores; strongly effervescent (8 percent
calcium carbonate equivalent); moderately alkaline (pH 8.2); clear
smooth boundary. (2 to 10 inches thick)
Bk1--5 to 10 inches; very pale brown (10YR 7/3) silt loam, brown
(10YR 5/3) moist; moderate medium and coarse subangular blocky
structure; slightly hard, very friable, slightly sticky and slightly
plastic; many very fine, common fine, and few medium roots; many very
fine, fine, and medium tubular pores; strongly effervescent (15 percent
calcium carbonate equivalent; strongly alkaline (pH 9.0); clear wavy
boundary. (3 to 10 inches thick)
Bk2--10 to 18 inches; very pale brown (10YR 8/3) silt loam, pale
brown (10YR 6/3) moist; moderate medium and coarse subangular blocky
structure; slightly hard and very friable; many very fine and medium,
and common fine roots; many very fine, fine and medium tubular pores;
violently effervescent (25 percent calcium carbonate equivalent); very
strongly alkaline (pH 9.4); clear smooth boundary. (5 to 10 inches
thick)
Bk3--18 to 31 inches; white (10YR 8/2) silt loam, pale brown (10YR
6/3) moist; massive; soft and very friable; few very fine, fine and
medium roots; many very fine, common fine and few medium tubular pores;
violently effervescent (18 percent calcium carbonate equivalent); 15
percent hard and firm cicada krotovinas; strongly alkaline (pH 8.6);
clear wavy boundary. (7 to 10 inches thick)
Czk--31 to 60 inches; very pale brown (10YR 7/3) silt loam, brown
(10YR 5/3) moist; massive; slightly hard and very friable; few very
fine, fine and medium roots; many very fine and common fine tubular
pores; strongly effervescent (11 percent calcium carbonate equivalent);
few fine irregularly shaped soft seams and filaments of salt;
moderately alkaline (pH 8.2).
TYPE LOCATION: Cassia County, Idaho; about 2 miles south of Bridge,
Idaho, about 2600 feet east and 1100 feet north of the southwest corner
of sec. 25, T. 15S., R. 26E.
RANGE IN CHARACTERISTICS:
Average annual soil temperature - 47 to 49 degrees F.
Control section - 10 to 15 percent clay, less than 15 percent coarser
than very fine sand
Depth to the calcic horizon - 5 to 18 inches
Thickness of the calcic horizon - 15 to 28 inches
A horizon
Value- 6 or 7 dry, 4 or 5 moist
Chroma- 2 or 3
Calcium carbonate equivalent - 4 to 15 percent
Reaction - moderately or strongly alkaline
Bk horizons
Value- 7 or 8 dry, 5 or 6 moist
Chroma- 2 or 3
Nodules or krotovina - 0 to 20 percent
Calcium carbonate equivalent - 15 to 30 percent
Czk horizons
Value- 6 or 7 dry, 4 or 5 moist
Chroma- 2 or 3
Calcium carbonate equivalent - 8 to 12 percent
Reaction - moderately to strongly alkaline
COMPETING SERIES: These are the Bahem, Bram, Nyssaton, Pogal, and
Portino series. Bahem soils have electrical conductivities of less
than 8 mmhos/cm in the profile. Bram soils are somewhat poorly
drained, have a fluctuating water table between depths of 3 and 6 feet,
and are moderately slowly permeable. Nyssaton soils have laminated
lake sediments at depths of 15 to 40 inches and are slowly permeable.
Pogal soils have an average annual soil temperature between 50 and 53
degrees F. and have the upper boundary of the calcic horizon at depths
of 20 inches or greater. Portino soils have basalt at depths of 20 to
40 inches.
GEOGRAPHIC SETTING: Idahome soils are on nearly level to very gently
sloping fan and high stream terraces. Elevations range from 4,400 to
5,400 feet. Slopes range from 0 to 4 percent. They formed in silty
alluvium. The climate is cold and moist in the winter and hot and dry
in the summer. The average annual precipitation ranges from 8 to 12
inches. The average summer temperature is about 65 degrees F. and the
average annual temperature ranges from 45 to 47 degrees F.. The
frost-free season is about 100 to 130 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Darkbull, Declo,
Mellor, and Strevell (T) soils. Darkbull soils have a skeletal
particle size control section. Declo and Strevell (T) soils have
coarse loamy particle size control sections. Mellor soils have a
natric horizon and are moderately slowly permeable. All these soils
are on fan terraces.
DRAINAGE AND PERMEABILITY: Well drained; slow runoff; moderate
permeability.
USE AND VEGETATION: Used primarily for rangeland. The potential
natural vegetation is mainly black greasewood, bottlebrush
squirreltail, and Sandburg bluegrass.
DISTRIBUTION AND EXTENT: Southern Idaho. The series is moderately
extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Cassia County, Idaho, 1986.
REMARKS: Diagnostic horizons and other features recognized in this
pedon are:
Ochric epipedon - the zone from 0 to 5 inches (A1 and A2 horizons).
Calcic horizon - the zone from 5 to 31 inches (Bk1, Bk2, and Bk3
horizons).
Particle-size control section - the zone from 10 to 40 inches (Bk2 and
Bk3 horizons and part of the Czk horizon).
National Cooperative Soil Survey