LOCATION SHELL NEEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Cumulic Haplustolls
TYPICAL PEDON: Shell silt loam, 1 percent slope in a cultivated field. (Colors are for dry soil unless otherwise noted.)
Ap--0 to 8 inches; grayish brown (10YR 5/2) silt loam, very dark brown (10YR 2/2) moist; weak fine granular structure; hard, very friable; slightly acid; abrupt smooth boundary.
A--8 to 24 inches; grayish brown (10YR 5/2) silt loam, very dark grayish brown (10YR 3/2) moist; weak fine and medium granular structure; hard, very friable; slightly acid; clear wavy boundary. (A horizon is 20 to 36 inches thick)
C1--24 to 33 inches; grayish brown (10YR 5/2) and light brownish gray (10YR 6/2) silt loam, very dark grayish brown (10YR 3/2) and grayish brown (10YR 5/2) moist; massive; hard, very friable; weak medium and fine bedding planes; neutral; clear wavy boundary.
C2--33 to 55 inches; grayish brown (10YR 5/2) and light brownish gray (10YR 6/2) silt loam, very dark grayish brown (10YR 3/2) and grayish brown (10YR 5/2) moist; few fine faint brown (7.5YR 4/4) moist; mottles; massive; hard, very friable; weak fine bedding planes; neutral; clear wavy boundary.
C3--55 to 60 inches; dark grayish brown (10YR 4/2) and light brownish gray (10YR 6/2) silt loam, very dark grayish brown (10YR 3/2) and dark grayish brown (10YR 4/2) moist; few fine faint brown (7.5YR 4/4) moist; mottles; massive; hard, very friable; weak fine bedding planes; slightly effervescent; slightly alkaline.
TYPE LOCATION: Colfax County, Nebraska; about 1 mile east and 2 miles north of Schuyler; located about 1,320 feet east and 100 feet north of the southwest corner, sec. 36, T. 18 N., R. 3 E.
RANGE IN CHARACTERISTICS:
Soil moisture: ustic moisture regime.
Mean annual soil temperature: 47 to 52 degrees F
Depth to secondary calcium carbonate: below 48 inches
Thickness of the solum and mollic epipedon: 20 to 36 inches
Note: Buried soils are below a depth of 30 inches in some pedons.
Particle-size control section (weighted average): silt loam and silty clay loam
Clay content: 20 to 30 percent
A horizon:
Hue: 10YR
Value: 3 through 5 and 2 or 3 moist
Chroma: 1 through 3 (dry or moist)
Texture: silt loam and less commonly loam or silty clay loam
Clay content: 15 to 32 percent
Reaction: medium acid through neutral
Thickness: 20 to 36 inches
C horizon:
Hue: 10YR
Value: 4 through 6 and 3 through 5 moist
Chroma: 2 or 3 (dry or moist)
Texture: typically silt loam and less commonly silty clay loam or loam
Clay content: 20 to 30 percent
Calcium carbonate equivalent: 0 to 5 percent
Reaction: medium acid through mildly alkaline
Note: Stratification occurs within a depth of 30 to 40 inches. Some pedons lack mottles in
the C horizon. Clayey material is below a depth of 40 inches in some pedons.
COMPETING SERIES: These are the:
Ackmen soils typically have hue of 7.5YR and occur in an area of lower precipitation.
Alcester soils have a B horizon and sola more than 36 inches thick.
Coleridge soils are wet in the series control section during the growing season and have a
Bw horizon.
Gabaldon soils have a B horizon and are calcareous throughout.
Hord soils have carbonates above a depth of 48 inches and have a B horizon.
Irak soils have hues redder than 10YR.
Muir soils have a regular decrease in organic carbon above a depth of 50 inches and have a B horizon.
Roxbury soils have carbonates above a depth of 15 inches.
Tobin soils are calcareous above a depth of 40 inches.
Trementina soils have carbonates above a depth of 36 inches.
Vega soils contain carbonates throughout the profile.
Other similar soils are the:
Cozad soils have a mollic epipedon 10 to 20 inches thick and are coarse-silty.
Grigston soils contain carbonates above a depth of 48 inches and a mollic epipedon 10 to
20 inches thick.
Hobbs soils do not have a mollic epipedon and are stratified above a depth of 10 inches.
Judson soils have a B horizon, a thicker solum, and are in a wetter moisture regime.
Kennebec soils have a Udic soil moisture regime.
Trent soils have a regular decrease in organic carbon.
GEOGRAPHIC SETTING:
Parent material: deep, silty alluvium that is stratified below a depth of 20 inches and
within a depth of 50 inches
Landform: flood plains on river valleys
Slopes: 0 to 2 percent
Mean annual temperature: 45 to 50 degrees F
Mean annual precipitation: 20 to 29 inches
Note: Thornthwaite annual P-E index ranges from 44 to 60.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the:
Aowa soils are stratified above a depth of 10 inches and are below Shell soils.
Colo soils have more clay in the control section, are more poorly drained, and are slightly lower in landscape positions.
Hall soils have an argillic horizon and are higher in landscape positions.
Hobbs soils are stratified above a depth of 10 inches and are below Shell soils.
Lawet soils have more clay in the control section, are more poorly drained, and are slightly lower in landscape positions.
Luton soils have more clay in the control section, are more poorly drained, and are slightly lower in landscape positions.
Zook soils have more clay in the control section, are more poorly drained, and are slightly lower in landscape positions.
DRAINAGE AND PERMEABILITY:
Drainage: Well
Permeability: Moderate
Surface runoff: Slow
Flooding: Rare or occasional for brief periods during the months of March to June.
Seasonal High Water Table: greater than 6 feet
USE AND VEGETATION: Most areas of Shell soils are cultivated and much of the acreage is irrigated. Corn, soybeans, alfalfa, and winter wheat are the principal crops.
DISTRIBUTION AND EXTENT: Northeastern and east-central Nebraska; LRR M Central Feed Grains and Livestock Region, MLRA 102B Loess Uplands and Till Plains; moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Colfax County, Nebraska, 1980.
REMARKS:
Diagnostic horizons and features recognized in this pedon are: Particle-size control section: The zone from 10 to 40 inches. (A, C1, and C2 horizons)
mollic epipedon: The zone from 0 to 36 inches. (Ap and A horizons)
Remarks: A clayey substratum phase of the Shell series is correlated.
Taxonomic Version: Eighth edition, 1998
ADDITIONAL DATA:
Series T Value: 5
Surface K value: .32
Surface Wind Erodibility Group: 6
Surface Wind Erodibility Index: 48