LOCATION CAPA SD

Established Series
Rev. AAF-KJH-AAO
08/2014

CAPA SERIES

The Capa series consists of very deep, moderately well drained soils formed in clayey sediments weathered from shale. Capa soils are in swales and toeslopes on terraces and uplands in MLRA 63A, Northern Rolling Pierre Shale Plains. Slopes range from 0 to 6 percent. Mean annual air temperature is about 9 degrees C (49 degrees F), and mean annual precipitation is about 432 millimeters (17 inches).

TAXONOMIC CLASS: Very-fine, smectitic, mesic Leptic Vertic Natrustolls

TYPICAL PEDON: Capa silt loam - on a northeast-facing, concave slope of 1 percent under grass at an elevation of 667 meters (2190 feet). (Colors are for dry soil unless otherwise noted.) When described on July 14, 1986, the soil was dry from 0 to 61 centimeters (0 to 24 inches) and moist below.

E--0 to 3 centimeters (0 to 1 inch); light brownish gray (10YR 6/2) silt loam, dark grayish brown (10YR 4/2) moist; weak fine subangular blocky and weak thin platy structure; soft, very friable; many roots; slightly acid; abrupt smooth boundary. [3 to 10 centimeters (1 to 4 inches) thick.]

Btn1--3 to 10 centimeters (1 to 4 inches); dark grayish brown (2.5Y 4/2) clay, very dark grayish brown (2.5Y 3/2) moist; light brownish gray (10YR 6/2) coatings on tops of columns; moderate coarse columnar structure parting to moderate medium and coarse subangular blocky; very hard, very firm, very sticky and plastic; many roots; few faint clay films on ped faces; neutral; clear wavy boundary.

Btn2--10 to 28 centimeters (4 to 11 inches); dark grayish brown (2.5Y 4/2) clay, very dark grayish brown (2.5Y 3/2) moist; moderate medium and coarse subangular blocky structure; very hard, very firm, very sticky and very plastic; many roots; few faint clay films on faces of peds; slight effervescence; slightly alkaline; clear wavy boundary. [Combined Btn horizons 10 to 38 centimeters (4 to 15 inches) thick.]

Btnkyz--28 to 38 centimeters (11 to 15 inches); grayish brown (2.5Y 5/2) clay, dark grayish brown (2.5Y 4/2) moist; moderate medium and coarse subangular blocky structure; very hard, very firm, very sticky and very plastic; common roots; few faint clay films on faces of peds; common fine accumulations of carbonate; few fine accumulations of gypsum and other salts; strong effervescence; moderately alkaline; gradual wavy boundary. [0 to 36 centimeters (0 to 14 inches) thick.]

Bkyz1--38 to 61 centimeters (15 to 24 inches); grayish brown (2.5Y 5/2) clay, dark grayish brown (2.5Y 4/2) moist; weak medium and coarse subangular blocky structure; hard, firm, very sticky and plastic; common roots; common fine accumulations of carbonate; many fine accumulations of gypsum and other salts; strong effervescence; moderately alkaline; gradual wavy boundary.

Bkyz2--61 to 79 centimeters (24 to 31 inches); grayish brown (2.5Y 5/2) clay, dark grayish brown (2.5Y 4/2) moist; weak medium and coarse subangular blocky structure; hard, firm, very sticky and plastic; few roots; common fine accumulations of carbonate; many fine accumulations of gypsum and other salts; strong effervescence; moderately alkaline; gradual wavy boundary. [Combined Bkyz horizons 13 to 66 centimeters (5 to 26 inches) thick.]

Cky--79 to 152 centimeters (31 to 60 inches); grayish brown (2.5Y 5/2) clay, dark grayish brown (2.5Y 4/2) moist; massive; hard, firm, very sticky and plastic; common fine accumulations of carbonate; many fine nests of gypsum; slight effervescence; moderately alkaline.

TYPE LOCATION: Jones County, South Dakota; about 2.4 kilometers (1.5 miles) north and 5.6 kilometers (3.5 miles) west of Okaton; located about 723 meters (2,373 feet) east and 122 meters (400 feet) north of the southwest corner of section 36, T. 1 S., R. 26 E; Okaton USGS quadrangle; latitude 43 degrees, 54 minutes, 34 seconds North and longitude 100 degrees, 57 minutes, 22 seconds West, NAD 83.

RANGE IN CHARACTERISTICS:
Soil Moisture Control Section:
The soil moisture control section is moist in some parts from April to July; intermittently moist from October to March; driest in August and September; typic ustic moisture regime.

Soil Temperature: 7 to 11 degrees C (45 to 52 degrees F)

Particle Size Control Section (weighted average):
Clay content: 55 to 75 percent
Sand content: 1 to 10 percent fine sand and coarser
Fragments: 0 to 1 percent

Depth to endosaturation: 100 to 150 centimeters (40 to 60 inches) from April to August

Depth to carbonates: 10 to 30 centimeters (4 to 12 inches)

Depth to visible accumulations of salts: 15 to 41 centimeters (6 to 16 inches)

E horizon:
Hue:10YR or 2.5Y
Value:5 or 6 and 3 to 5 moist
Chroma:1 or 2
Texturesilt loam or loam
Clay content: 20 to 26 percent
Sand content: 20 to 30 percent
Reaction: moderately acid to neutral
Cracks: 15 to 30 millimeters (0.5 to 1 inch) wide when dry
Note: Some pedons have an Ap horizon. When present it has the color and reaction of the Bt horizon. It is silty clay loam, clay loam, silty clay or clay.

Btn horizon:
Hue:10YR, 2.5Y or 5Y
Value: 4 or 5 and 2 to 4 moist
Chroma: 1 or 2
Texture:
Clay content: 60 to 75 percent
Sand content: 5 to 15 percent
Exchangeable Sodium Percentage: greater than 15 and magnesium plus sodium exceeds calcium plus exchangeable acidity
Sodium Absorption Ratio: typically greater than 13 but ranges from 10 to 25
Reaction: neutral to moderately alkaline
Cracks: 15 to 30 millimeters (0.5 to 1 inch) wide when dry

Btnkyz horizon (if present):
Hue: 10YR, 2.5Y, or 5Y
Value: 4 to 6 and 3 to 5 moist
Chroma: 1 or 2
Texture: clay or silty clay
Clay content: 50 to 70 percent
Sand content: 5 to 15 percent
Concentrations: 2 to 20 percent of gypsum, carbonate, and other saltsReaction: neutral to moderately alkaline
Cracks: 15 to 30 millimeters (0.5 to 1 inch) wide when dry

Bkyz horizon:
Hue: 10YR, 2.5Y, or 5Y
Value: 4 to 6 and 3 to 5 moist
Chroma: 1 or 2
Texture: clay or silty clay
Clay content: 50 to 70 percent
Sand content: 5 to 15 percent
Concentrations: 2 to 20 percent of gypsum, carbonate, and other salts
Reaction: slightly or moderately alkaline

C horizon
Hue: 2.5Y or 5Y
Value: 5 to 7 and 4 to 6 moist
Chroma: 1 or 2
Texture: clay or silty clay
Clay content: 50 to 70 percent
Sand content: 5 to 15 percent
Concentrations: 2 to 20 percent of gypsum, carbonate, and other salts
Reaction: slightly or moderately alkaline

COMPETING SERIES: There are no series in the same family.

GEOGRAPHIC SETTING:
Parent material: locally transported clayey sediments consisting of material weathered from marine shale of the Pierre Formation
Landscape: undulating uplands
Landform: swales, toeslopes, or terraces
Slopes: 0 to 6 percent
Slope shape: concave or linear
Elevation: 400 to 800 meters (1,312 to 2,624 feet)
Mean annual air temperature: 6 to 10 degrees C (43 to 50 degrees F)
Mean annual precipitation: 400 to 700 millimeters (16 to 27 inches)
Mean growing season precipitation: 300 to 430 millimeters (12 to 17 inches)
Frost-free period: 130 to 160 days
Growing degree days: 2800 to 3300

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Kirley, Lakoma, Mosher, Opal and Promise soils. Kirley, Lakoma, Opal and Promise soils do not have a natric horizon. They are on higher parts of the landscape. Mosher soils have salts at a depth greater than 16 inches. They are on slightly higher positions on the landscape.

DRAINAGE AND PERMEABILITY:
Drainage: Moderately well drained
Saturated Hydraulic Conductivity: Moderately low
Surface Runoff: negligible to very high depending on slope shape and percentage

USE AND VEGETATION: Used primarily for livestock grazing. Native vegetation is mainly western wheatgrass, blue grama, buffalograss, and cactus.

DISTRIBUTION AND EXTENT: West-central South Dakota; Land Resource Region F, Northern Great Plains Spring Wheat Region and Land Resource Region G, Western Great Plains Range and Irrigated Region, Major Land Resource Area 53B, 54, 63A, and 63B.The series is of moderate extent.

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

SERIES ESTABLISHED: Jones County, South Dakota, 1991.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Particle-size control section: the zone from 3 to 38 centimeters [1 to 15 inches (Btn1, Btn2 and Btnkyz horizons)]
Mollic epipedon: the zone from 0 to 28 centimeters [0 to 11 inches (E, Btn1 and Btn2 horizons)]
Natric horizon:the zone from 3 to 38 centimeters [1 to 15 inches (Btn1, Btn2 and Btnkyz horizons)] Vertic subgroup properties: linear extensibility of more than 6.0 cm within a depth of 100 centimeters (40 inches)
Taxonomic Version: Twelfth Edition, 2014. The previous classification was Very-fine, smectitic, mesic Vertic Natrustolls.

AAO 8/2014 Updated the taxonomic classification, updated the Range in Characteristics, type location description, horizon nomenclature, parent material and landform, distribution and extent, geographic setting, and saturated hydraulic conductivity; added metric units to all measurements and temperatures, and changed format to tabular.

National Cooperative Soil Survey
U.S.A.