LOCATION TILFORD SD+WY

Established Series
Rev. TJO/JWW
04/2015

TILFORD SERIES

The Tilford series consists of very deep, well drained soils formed in local alluvium and residuum derived from reddish siltstone and silty shale. Tilford soils are on on backslopes and footslopes of fans, terraces, and hillslopes. Slopes range from 0 to 15 percent slopes. Mean annual precipitation is about 445 mm (17.5 inches), and mean annual air temperature is about 8 degrees C (47 degrees F).

TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Typic Haplustolls

TYPICAL PEDON: Tilford silt loam - on a north-facing slope of 4 percent in native grass. When described the soil was moist throughout. (Colors are for dry soil unless otherwise stated.)

A--0 to 13 cm (0 to 5 inches); brown (7.5YR 4/2) silt loam, dark brown (7.5YR 3/2) moist; weak fine granular structure; slightly hard, very friable, nonsticky and nonplastic; neutral; clear wavy boundary. (3 to 10 inches thick)

Bw1--13 to 23 cm (5 to 9 inches); dark reddish gray (5YR 4/2) silt loam, dark reddish brown (5YR 3/2) moist; weak medium prismatic structure parting to weak medium subangular blocky; slightly hard, friable, slightly sticky and slightly plastic; slight effervescence; neutral; gradual wavy boundary.

Bw2--23 to 41 cm (9 to 16 inches); reddish brown (5YR 5/3) silt loam, dark reddish brown (5YR 3/3) moist; weak coarse prismatic structure parting to weak medium subangular blocky; slightly hard, friable, slightly sticky and slightly plastic; slight effervescence; slightly alkaline; gradual wavy boundary.

Bw3--41 to 66 cm (16 to 26 inches); reddish yellow (5YR 6/6) silt loam, yellowish red (5YR 4/6) moist; weak coarse prismatic structure parting to weak coarse blocky; slightly hard, friable, slightly sticky and slightly plastic; slight effervescence; moderately alkaline; diffuse wavy boundary. (Combined thickness of the Bw horizons is 15 to 63 cm.)

Bky--66 to 100 cm (26 to 40 inches); light reddish brown (2.5YR 6/4) loam, red (2.5YR 4/6) moist; weak coarse prismatic structure parting to weak coarse subangular blocky; slightly hard, friable, slightly sticky and slightly plastic; common fine and medium accumulations of gypsum; common fine and medium accumulations of carbonates; strong effervescence; moderately alkaline. (13 to 50 cm thick)

C--100 to 200 cm (40 to 80 inches); light reddish brown (2.5YR 6/4) loam, red (2.5YR 4/6) moist; massive; slightly hard, friable, nonsticky and nonplastic; few accumulations of gypsum and carbonates; strong effervescence; moderately alkaline.

TYPE LOCATION: Meade County, South Dakota; about 3.3 km (2 miles) east and 1.6 km (1 mile) south of Piedmont; about 122 meters (400 feet) west and 427 meters (1,400 feet) south of the northeast corner of sec. 15, T. 3 N., R. 6 E.; Blackhawk quadrangle; 44 degrees 13 minutes 25.5 seconds north latitude, and 103 degrees 22 minutes and 26.7 degrees west longitude; NAD 83.

RANGE IN CHARACTERISTICS:
Mollic epipedon thickness: 18 to less than 50 cm (7 to less than 20 inches)
Depth to calcium carbonates: 0 to 25 cm (0 to 10 inches)
Depth to bedrock: typically is greater than 150 cm (60 inches); weakly cemented siltstone and/or silty shale may occur between 100 and 150 cm (40 and 60 inches) in some pedons
Clay content (control section average): 18 to 30 percent
Calcium carbonate content (control section average): 4 to 14 percent
Rock fragments (control section average): 0 to 10 percent rounded and subrounded gravel

A horizon:
Hue: 5YR, 7.5YR, or 10YR
Value: 3 to 5 dry, 2 or 3 moist
Chroma: 2 or 3
Texture: silt loam, loam
Reaction: neutral or slightly alkaline

Bw horizon:
Hue: 2.5YR, 5YR, or 7.5YR
Value: 4 to 6 dry, 3 to 5 moist
Chroma: 2 to 6
Texture: silt loam, loam, silty clay loam
Reaction: neutral through moderately alkaline

Bky (and Bk) horizon:
Hue: 2.5YR, 5YR, or 7.5YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 3 to 6
Texture: silt loam, loam, silty clay loam
Reaction: slightly alkaline or moderately alkaline

C horizon:
Hue: 2.5YR, 5YR, or 7.5YR
Value: 5 to 7 dry, 4 to 6 moist
Chroma: 4 to 6
Texture: silt loam, loam, silty clay loam
Reaction: slightly alkaline or moderately alkaline

A 2C horizon occurs between 100 and 150 cm (40 to 60 inches) in some pedons. It has properties similar to the C horizon except textures are very gravelly and extremely gravelly loam, fine sandy loam, sandy loam, and coarse sandy loam. It has 35 to 60 percent rounded and subrounded gravel, 5 to 25 percent cobble, and 0 to 5 percent stones. Fragments are from mixed igneous, metamorphic, and sedimentary sources.

COMPETING SERIES: These are the Bend, Homme, Nuckolls, and Uly series.
Bend - have hue of 10YR or yellower, and have varves 1 to 2 mm in thickness in the lower part of the profile
Homme - have hue of 10YR or yellower, have free carbonates deeper than 25 cm, and lack secondary accumulations of gypsum
Nuckolls - have free carbonates deeper than 50 cm, typically do not have secondary accumulations of carbonates or gypsum, and have mean annual temperatures of 10 to 14 degrees C
Uly - have hue yellower than 7.5YR in the A and B horizons, and typically do not have secondary accumulations of carbonates or gypsum

GEOGRAPHIC SETTING:
Parent material: silty alluvium and residuum derived from reddish-colored silty shale and siltstone, primarily of the Spearfish formation
Landform/Landscape: nearly level to rolling fans, terraces, and hillslopes on uplands and in valleys
Slopes: 0 to 15 percent
Elevation: 914 to 1,524 meters (3,000 to 5,000 feet)
Mean annual air temperature: 7 to 10 degrees C (45 to 50 degrees F)
Mean annual precipitation: 406 to 560 mm (16 to 22 inches)
Precipitation pattern: Over one-half the mean annual precipitation falls as snow and rain during the period March through July
Frost-free season: 120 to 140 days

GEOGRAPHICALLY ASSOCIATED SOILS:
Nevee - do not have a mollic epipedon and are coarse-silty; on similar and slightly higher landscape positions
Spearfish - are shallow to siltstone bedrock; on higher and steeper landscape positions
St. Onge - are fine-loamy and have mollic epipedons greater than 50 cm (20 inches) thick; on lower landscape positions
Swint - are fine-loamy, and have an irregular decrease in organic matter; on lower landscape positions
Vale - have argillic horizons; on similar landscape positions

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage: Well
Ksat: moderately high
Surface runoff: low to medium, depending on slope

USE AND VEGETATION:
Use: native range (livestock grazing), pasture, hayland, and cropland. Small grains, corn (where irrigated), and alfalfa are the principal crops.
Native vegetation: little bluestem, big bluestem, western wheatgrass, green needlegrass, needleandthread, blue grama, and forbs.

DISTRIBUTION AND EXTENT: Tilford soils occur primarily in the Red Valley physiographic area of the Black Hills Foothills in western South Dakota and northeastern Wyoming. LRR G, MLRA 61. The series is of moderate extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Salina, Kansas

SERIES ESTABLISHED: Meade County, South Dakota, 1974.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - 0 to 41 cm (0 to 16 inches); (A, Bw1, and Bw2 horizons)
Cambic horizon - 13 to 100 cm (5 to 40 inches); (Bw1, Bw2, Bw3, and Bky horizons)
Secondary accumulations of calcium carbonate and gypsum - 66 to 100 cm (26 to 40 inches); (Bky horizon)

The taxonomic classification of the series is changed from Torriorthentic Haplustolls to Typic Haplustolls with this update. The type location for the series is in the typic-ustic moisture regime in MLRA 61, and the soil has a diagnostic cambic horizon.

Taxonomic Version: Keys to Soil Taxonomy, Twelfth Edition, 2014

ADDITIONAL DATA: KSSL site number S2014WY011001; lab pedon number 15N0170.

National Cooperative Soil Survey
U.S.A.