LOCATION KILLPACK UT+CO

Established Series
REV: JLS/CRP/JCK
12/2017

KILLPACK SERIES

The Killpack series consists of moderately deep, well drained soils that formed in slope alluvium or alluvium over residuum derived from shale. Killpack soils are on hills, pediments and strath terraces. Slopes are 0 to 25 percent. Average annual precipitation is about 178 mm and mean annual air temperature is about 9 degrees C.

TAXONOMIC CLASS: Fine-silty, mixed, active, mesic Typic Haplocambids

TYPICAL PEDON: Killpack clay loam in cropland. (Colors are for dry soil unless otherwise noted.)

Ap--0 to 23 cm; grayish brown (2.5Y 5/2) clay loam, dark grayish brown (2.5Y 4/2) moist; weak medium and fine granular structure; hard, firm, slightly sticky and slightly plastic; common fine roots; common fine pores; strongly effervescent; slightly alkaline (pH 7.8); clear smooth boundary. (9 to 18 cm thick)

Bw--23 to 58 cm; light brownish gray (2.5Y 6/2) clay loam, grayish brown (2.5Y 5/2) moist; moderate coarse subangular blocky parting to weak fine subangular blocky structure; hard, firm, moderately sticky and moderately plastic; few fine roots; few fine pores; strongly effervescent; slightly alkaline (pH 7.7); gradual wavy boundary. (20 to 53 cm thick)

BCy--58 to 74 cm; light brownish gray (2.5Y 6/2) silty clay loam, grayish brown (2.5Y 5/2) moist; massive; hard, very firm, moderately sticky and moderately plastic; few fine roots; many coarse gypsum crystals; strongly effervescent; slightly alkaline (pH 7.7); gradual wavy boundary. (9 to 25 cm thick)

Cr--74 to 152 cm; light brownish gray weathered shale.

TYPE LOCATION: Emery County, Utah; 3.2 kilometers northwest of Elmo, northeast of the Elmo road and the Cleveland-Price road; 747 meters north and 91 meters east of the SW corner of sec. 30, T. 16 S., R. 10 E.; Elmo USGS quad; lat. 39 degrees 24 minutes 19 seconds N. and long. 110 degrees 51 minutes 5 seconds W., NAD 27.

RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 8 to 12 degrees C
Depth to paralithic contact - 50 to 100 cm
Particle-size control section (weighted average):
Clay content - 18 to 35 percent
Sand content (fine or coarser) - 0 to 15 percent

A horizon
Hue: 2.5Y, 5Y or 10YR
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 2, 3, or 4 dry or moist
Texture: clay loam, silty clay loam or loam
Clay content: 10 to 35 percent
Rock fragments: 0 to 15 percent
Sodium adsorption ratio: 0 to 8
Electrical conductivity: 0 to 8 mmhos/cm
Reaction: pH 7.4 to 8.8

Bw horizon
Hue: 2.5Y, 5Y or 10YR
Value: 5, 6, or 7 dry; 4 or 5 moist
Chroma: 2, 3, or 4 dry or moist
Texture: silty clay loam, clay loam or silt loam
Clay content: 18 to 35 percent
Rock fragments: 0 to 15 percent
Sodium adsorption ratio: 0 to 8
Electrical conductivity: 2 to 16 mmhos/cm
Reaction: pH 7.4 to 8.8

BCy horizon
Hue: 2.5Y, 5Y or 10YR
Value: 5, 6 or 7 dry; 4 or 5 moist
Chroma: 2, 3 or 4 dry or moist
Texture: silty clay loam, clay loam and silt loam
Clay content: 18 to 35 percent
Rock fragments: 0 to 10 percent gravel
Pararock fragments: 0 to 60 percent parachanners
Gypsum content: 2 to 10 percent
Sodium adsorption ratio: 0 to 8 percent
Electrical conductivity: 2 to 16 mmhos/cm
Reaction: pH 7.4 to 8.8

Some pedons have a By in place of the BCy horizon.

COMPETING SERIES:
Fordbutte (NM) - have secondary calcium carbonate accumulation; have a lithologic discontinuity
Sagers (UT) - are very deep

GEOGRAPHIC SETTING:
Landform - hills, pediments and strath terraces
Elevation - 1,220 to 1,950 meters
Slope - 0 to 25 percent
Parent material - slope alluvium or alluvium over residuum derived from shale
Mean annual air temperature - 7.2 to 11 degrees C
Mean annual precipitation - 127 to 229 mm
Precipitation pattern - wettest months are July to October and driest months are December and June.
Frost-free period - 120 to 180 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Chipeta, Persayo, Billings and Libbings soils.

DRAINAGE AND PERMEABILITY: Well drained; moderately slow permeability.

USE AND VEGETATION: Killpack soils are used for cropland, hayland, irrigated pasture, and rangeland. Native vegetation is shadscale saltbush, mat saltbush, Indian ricegrass, winterfat, James' galleta, and squirreltail.

DISTRIBUTION AND EXTENT: Killpack soils are of moderate extent in eastern Utah and western Colorado. MLRA 34B and 36.

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Bozeman, Montana

SERIES ESTABLISHED: Emery County, Utah, 1972.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon from - 0 to 23 cm (Ap horizon)
Cambic horizon from - 23 to 74 cm (Bw and BCy horizons)
Gypsum accumulation from - 58 to 74 cm (BCy horizon)
Paralithic contact at - 74 cm
Particle-size control section - 25 to 74 cm (part of Bw and BCk horizon)

Killpack soils have a mesic temperature regime and an aridic moisture regime.

National Cooperative Soil Survey
U.S.A.