LOCATION KUNATON IDEstablished Series
The Kunaton series consists of shallow, well drained soils on basalt
plains. They formed in loess or silty alluvium. Permeability is
slow. Slopes are 0 to 12 percent. The average annual precipitation is
about 12 inches, and the average annual air temperature is about 51
degrees F.
TAXONOMIC CLASS: Clayey, smectitic, mesic, shallow Abruptic Xeric Argidurids
Xerollic Durargids.
TYPICAL PEDON: Kunaton silt loam - rangeland. (Colors are for dry
soil unless otherwise noted.)
E--0 to 4 inches; pale brown (10YR 6/3) silt loam, dark yellowish
brown (10YR 4/4) moist; weak thin platy structure; slightly hard,
friable, slightly sticky and slightly plastic; many very fine and fine
roots; many very fine and fine vesicular pores; mildly alkaline (pH
7.4); abrupt smooth boundary. (3 to 5 inches thick)
Bt--4 to 9 inches; brown (7.5YR 5/4) silty clay, dark brown (7.5YR
4/4) moist; dark brown (7.5YR 4/4) coatings moist or dry on faces of
peds; moderate very coarse prismatic structure parting to strong medium
subangular and fine angular blocky; very hard, friable, sticky and
plastic; common very fine roots; many very fine and fine tubular pores;
continuous thick clay films on faces of peds and in pores; mildly
alkaline (pH 7.7); clear smooth boundary. (4 to 8 inches thick)
Btk--9 to 13 inches; very pale brown (10YR 7/3) silty clay, dark
yellowish brown (10YR 4/4) moist; moderate medium and coarse subangular
blocky structure; hard, friable, sticky and plastic; few very fine
roots; common very fine and fine tubular pores; many moderately thick
clay films on faces of peds and in pores; common fine lime veins
between peds; strongly effervescent; strongly alkaline (pH 8.6); abrupt
smooth boundary. (3 to 7 inches thick)
Bkqm--13 to 25 inches; very pale brown (10YR 7/4) duripan, light
yellowish brown (10YR 6/4) moist; white (10YR 8/2) lime coatings
covering the indurated plate-like laminations; dense opalized layer 3
to 6 millimeters thick on upper zone of cementation, laminations are 1
to 3 inches thick separated by 0.5 to 2 inches of loose, violently
effervescent soil material; strongly alkaline (pH 8.6); abrupt wavy
boundary. (8 to 20 inches thick)
R--25 inches; highly jointed and fractured vesicular basalt.
TYPE LOCATION: Ada County, Idaho; about 4.75 miles east of Kuna;
approximately 80 feet south and 1,070 feet east of NW corner of section
27, T.2N., R.1E.
RANGE IN CHARACTERISTICS:
Average annual soil temperature - 50 to 54 degrees F
Depth to duripan - 10 to 20 inches
Depth to bedrock - 20 to 40 inches
Texture of control section - SICL, SIC, C
Clay content in control section - 38 to 55 percent
E horizon
Value- 5 through 7 dry, 3 or 4 moist
Chroma- 2 through 4
Bt horizon
Hue- 7.5YR or 10YR
Value- 5 through 7 dry, 3 through 5 moist
Chroma- 3 or 4
COMPETING SERIES: These are the Fulstone, Puls, Ridenbaugh, and
Rogerson(T) series. Puls soils lack free carbonates in the lower part
of the solum. Ridenbaugh soils lack bedrock at depths of 20 to 40
inches. Rogerson soils have average annual soil temperature of 47 to
50 degrees F and lack carbonates above the duripan. Fulstone soils are
greater than 40 inches deep to bedrock.
GEOGRAPHIC SETTING: Kunaton soils are on basalt plains. Elevations
range from 2,700 to 4,200 feet. Slopes are 0 to 12 percent. The soils
formed in a veneer of loess or silty alluvium which overlies basalt.
Average annual precipitation ranges from 9 to 12 inches. Average
January temperature is about 28 degrees F, average July temperature is
about 75 degrees F, and average annual temperature is 48 to 53 degrees
F. Frost-free period is about 110 to 160 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Chilcott, Colthorp,
Elijah, Purdam, and Sebree soils and the competing Ridenbaugh soils.
Chilcott, Elijah, Purdam, and Sebree soils are 20 to 40 inches deep to
the pan. Colthorp soils have less than 35 percent clay in the textural
control section. These soils are on landscape positions similar to
Kunaton soils.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; slow
permeability.
USE AND VEGETATION: These soils are used dominantly for rangeland with
some irrigated cropland. Principal crops are small grain, corn,
alfalfa and improved pasture. Vegetation in the potential natural
plant community is Wyoming big sagebrush, bluebunch wheatgrass,
Sandberg bluegrass, and Thurber needlegrass.
DISTRIBUTION AND EXTENT: Southwestern Idaho. The soils are moderately
extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Ada County, Idaho, 1977.
REMARKS: Diagnostic horizons and features recognized in this pedon
are:
Ochric epipedon - the zone from 0 to 4 inches (E horizon)
Argillic horizon - the zone from 4 to 13 inches (Bt and Btk horizons).
Indurated duripan - the zone from 13 to 25 inches (Bkqm horizon).
Particle-size control section - the zone from 0 to 13 inches.
National Cooperative Soil Survey