LOCATION STANROD IDEstablished Series
The Stanrod series consists of very deep, well drained, moderately
slowly permeable soils that are formed in mixed alluvium. They are on
coalesced fan terraces and have slopes of 2 to 8 percent. The average
annual temperature is about 46 degrees F, the average annual
precipitation is about 10 inches.
TAXONOMIC CLASS: Coarse-silty, mixed, superactive, mesic Xeric Natrargids
TYPICAL PEDON: Stanrod silt loam--rangeland. On a 4 percent, single
slope, northeast aspect, 5,320 feet elevation. The profile was moist
below 8 inches when described. This profile was described June 24,
1982. Colors are for air-dry soil unless otherwise stated.
A--0 to 3 inches; very pale brown (10YR 7/3) silt loam, brown (10YR
4/3) moist; weak very thick platy structure parting to moderate thin
platy; slightly hard, very friable, slightly sticky and slightly
plastic; many very fine roots; many very fine and fine vesicular pores;
slightly effervescent; 5 percent pebbles; strongly alkaline (pH 8.8)
abrupt smooth boundary. (2 to 4 inches thick)
Btn--3 to 6 inches; very pale brown (10YR 7/3) silty clay loam,
brown (10YR 4/3) moist; strong medium prismatic structure parting to
strong fine angular blocky; very hard, friable, sticky and very
plastic; many very fine and few fine roots; many very fine and common
fine tubular pores; many thin and moderately thick clay films on faces
of peds and line pores; strongly alkaline (pH 8.6); clear smooth
boundary. (2 to 4 inches thick)
Btkn--6 to 8 inches; very pale brown (10YR 7/3) silty clay loam,
pale brown (10YR 6/3) moist; moderate medium prismatic structure
parting to strong fine and medium angular blocky; hard, friable, sticky
and plastic; common very fine roots; many very fine and common fine
tubular pores; strongly effervescent; few thin clay films on faces of
peds and line pores; very strongly alkaline (pH 9.2); clear smooth
boundary. (2 to 4 inches thick)
Bk1--8 to 11 inches; white (10YR 7/3) silt loam, pale brown (10YR
6/3) moist; weak coarse subangular blocky structure; slightly hard,
very friable, slightly sticky and slightly plastic; common very fine
and few fine roots; many very fine and common fine tubular pores;
strongly effervescent; very strongly alkaline (pH 9.4); clear smooth
boundary. (1 to 5 inches thick)
Bk2--11 to 17 inches; white (10YR 8/2) silt loam, pale brown (10YR
6/3) moist; weak medium and coarse subangular blocky structure;
slightly hard, very friable, slightly sticky and slightly plastic; few
very fine roots; many very fine tubular pores; violently effervescent;
very strongly alkaline (pH 9.2); clear smooth boundary. (6 to 12
inches thick)
Bk3--17 to 30 inches; white (10YR 8/2) silt loam, very pale brown
(10YR 7/3) moist; massive; slightly hard, very friable, slightly sticky
and slightly plastic; few very fine roots; common very fine and few
fine tubular pores; 10 percent very hard and firm cicada krotovinas;
violently effervescent; violently effervescent lime segregated in few
fine irregularly shaped seams; strongly alkaline (pH 9.0); gradual wavy
boundary. (10 to 25 inches thick)
Bkz--30 to 53 inches; very pale brown (10YR 7/3) silt loam,
yellowish brown (10YR 5/4) moist; massive; slightly hard and very
friable; few very fine roots; common very fine tubular pores; 10
percent pebbles; common fine irregularly shaped soft masses and
filaments of salt; strongly effervescent; moderately alkaline (pH 8.4);
abrupt wavy boundary. (12 to 25 inches thick)
2C--53 to 60 inches; very pale brown (10YR 8/3) gravelly silt loam;
light yellowish brown (10YR 6/4) moist; massive; slightly hard and very
friable; common very fine tubular pores; 25 percent pebbles, 5 percent
cobbles; violently effervescent; moderately alkaline (pH 8.4).
TYPE LOCATION: Cassia County Idaho; about 2 miles west of Naf, Idaho,
150 feet east, 1,100 feet north of the southwest corner of section 20,
T. 16 S., R. 27 E.
RANGE IN CHARACTERISTICS:
Control section
Depth to secondary lime - 4 to 9 inches
Rock fragments - 0 to 10 percent
Average annual soil temperature - 47 to 49 degrees F
Clay content - 10 to 15 percent
A horizon
Value- 5 through 7 dry, 3 or 4 moist
Chroma- 2 or 3
Reaction - moderately to very strongly alkaline
Bt horizon
Value- 5 through 7 dry, 4 through 6 moist
Chroma- 2 or 3
Clay content - 20 to 35 percent
Texture - SIL or SICL
Sodium absorbtion ratio - 20 to 40
Reaction - moderately to very strongly alkaline
Bk horizon
Value- 6 through 8 dry, 4 through 6 moist
Chroma- 2 through 4
Texture - SIL or L
Rock fragment content - 0 to 10 percent
Reaction - moderately to very strongly alkaline
2C horizon
Value- 6 or 7 dry, 4 or 5 moist
Chroma- 3 or 4
Texture - GR-SIL, GR-L, GRV-L, or GRV-SL
Rock fragment content - 15 to 50 percent
Reaction - moderately to very strongly alkaline
This horizon is absent in some pedons.
COMPETING SERIES: There are no competing series listed in the same
family. Similar soils are the Antelope Springs and Mellor series.
These soils have a natric horizon with a lower boundary greater than 10
inches.
GEOGRAPHIC SETTING: Stanrod soils are on coalesced fan terraces.
Slopes range from 2 to 8 percent. Elevation ranges from 4.700 to 5,600
feet. The soil formed in mixed alluvium. The average annual
precipitation is about 8 to 12 inches, the average annual air
temperature is about 45 to 47 degrees F, and the frost-free season is
95 to 120 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Darkbull, Declo, and
Mellor series. These soils are on fan terraces. Darkbull and Declo
soils do not have a natric horizon. Mellor soils have a natric horizon
deeper than 10 inches.
DRAINAGE AND PERMEABILITY: Well drained. Medium runoff. Moderately
slowly permeable.
USE AND VEGETATION: Stanrod soils are used for range and wildlife
habitat. The native vegetation is shadscale, slatbush, and bottlebrush
squirreltail.
DISTRIBUTION AND EXTENT: The soils of this series are not extensive in
Southern Idaho.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Cassia County, Idaho, 1986.
REMARKS: Diagnostic horizons and features recognized in this pedon
are:
Ochric epipedon - the zone from the surface to 3 inches (A horizon)
Argillic horizon - the zone from 3 to 8 inches (Btn and Btkn horizons)
Natric feature - the argillic horizon has prismatic structure and an
SAR greater than 20
Calcic horizon - the zone from 8 to 30 inches (Bk1, Bk2, and Bk3
horizons)
Particle size control section - the zone from 3 to 40 inches (Btn,
Btkn, Bk1, Bk2, Bk3, and Bkz horizons)
National Cooperative Soil Survey