LOCATION INTERIOR                SD+NE

Established Series
Rev. WTS/JWW
08/2011

INTERIOR SERIES

The Interior series consists of very deep, well drained soils formed in sodium enriched alluvium on flood plains, low terraces, fan remnants, and in drainageways. Saturated hydraulic conductivity is moderately high. Slopes range from 0 to 3 percent. Mean annual precipitation is about 405 mm and mean temperature about 9 degrees C.

TAXONOMIC CLASS: Fine-silty, mixed, superactive, calcareous, mesic Aridic Ustifluvents

TYPICAL PEDON: Interior loam - on a slightly convex slope of 1 percent under native grass. When described the soil was dry throughout. (Colors are for dry soil unless otherwise stated)

A--0 to 10 cm; light gray (10YR 7/2) loam, brown (10YR 5/3) moist; weak very thin platy structure; soft, very friable, nonsticky and nonplastic; common fine to coarse roots; strong effervescence; moderately alkaline; clear smooth boundary. (5 to 15 cm thick)

C1--10 to 33 cm; light gray (10YR 7/2) stratified loam, brown (10YR 5/3) moist; massive; soft, friable, nonsticky and nonplastic; common fine and medium roots; strong effervescence; moderately alkaline; clear smooth boundary.

C2--33 to 56 cm; light gray (10YR 7/2) stratified loam, brown (10YR 5/3) moist; massive; hard, friable, slightly sticky and slighly plastic; common fine and medium roots; strong effervescence; moderately alkaline; clear smooth boundary.

C3--56 to 89 cm; light gray (10YR 7/2) and very pale brown (10YR 8/2) stratified silt loam, grayish brown (10YR 5/2) moist; massive; hard, friable, slightly sticky and slightly plastic; common fine and medium roots; strong effervescence; moderately alkaline; gradual wavy boundary.

C4--89 to 117 cm; light gray (10YR 7/2) and very pale brown (10YR 8/2) stratified silt loam and silty clay loam, light brownish gray (10YR 6/2) and brown (10YR 5/3) moist; massive; hard, friable, slightly sticky and slightly plastic; few fine roots in upper parts; strong effervescence; moderately alkaline.

C5--117 to 152 cm; light gray (10YR 7/2) loam with thin layers of silty clay loam and very fine sandy loam, light brownish gray (10YR 6/2) moist; massive; slightly hard, friable, nonsticky and slightly plastic; strong effervescence; moderately alkaline. (Combined thickness of the C horizon is greater than 137 cm)

TYPE LOCATION: Jackson County, South Dakota; about 1 mile south and 1 mile east of Interior; 245 feet north and 710 feet west of the southeast corner of Sec. 9, T. 4 S., R. 18 E.; 43 degrees, 46 minutes, 20.1 seconds north latitude, and 101 degrees, 57 minutes, 42.0 seconds west longitude; NAD 83.

RANGE IN CHARACTERISTICS:
A horizon:
Hue: 10YR to 5Y
Value: 5 to 8, 4 to 7 moist
Chroma: 1 to 3
Texture: Loam, silt loam, or silty clay loam
Sodium Adsorption Ratio: 10 to 25
Reaction: Slightly alkaline to strongly alkaline

C horizon:
Hue: 10YR to 5Y
Value: 5 to 8, 4 to 7 moist
Chroma: 1 to 4
Texture: Individual horizons typically average loam, silt loam, or silty clay loam. The cumulative horizon is stratified and may contain layers ranging from very fine sandy loam to silty clay.
Clay content: typically is 18 to 27 percent, but may range to 35 percent
Sand content: less than 15 percent fine and coarser sand, and from 10 to 50 percent very fine sand
Sodium Adsorption Ratio: 13 to 35
Reaction: Moderately alkaline to strongly alkaline

COMPETING SERIES:
Naplene and Zuniven - both of these soils have an SAR less than 13 in the control section; additionally Naplene has lower activity clay and Zuniven is moderately well drained

GEOGRAPHIC SETTING:
Landscape: badlands and plains
Landform: flood plains, low terraces, fan remnants, and drainageways
Parent material: sodic alluvium derived primarily from White River formation material
Slopes: 0 to 3 percent
Mean annual air temperature: 7 to 12 degrees C
Mean annual precipitation: 355 to 455 mm

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cedarpass, Denby and Orella soils.
Cedarpass and Denby soils have cambic horizons and occur on higher landscape positions than Interior.
Orella soils are shallow to paralithic contact and are clayey. They occur on higher landscape positions than Interior.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage: Well
Runoff: Low
Ksat: Moderately high
Flooding: Rare to frequent

USE AND VEGETATION: Most areas are in native grass. The native vegetation dominantly is needlegrass, little bluestem, western wheatgrass, blue grama, sideoats grama, sedges and forbs.

DISTRIBUTION AND EXTENT: Southwestern South Dakota. It is of moderate extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado

SERIES ESTABLISHED: Jackson County, South Dakota, 1984.

REMARKS: Diagnostic horizons and features recognized in this pedon:
Ochric epipedon - the zone from the surface of the soil to a depth of 4 inches (A horizon).

Taxonomic Version: Keys to Soil Taxonomy, Eleventh Ed., 2010

ADDITIONAL DATA:

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National Cooperative Soil Survey
U.S.A.