LOCATION SCHRADER                CO

Established Series
Rev. GB//DKR/SJJ
06/2015

SCHRADER SERIES

The Schrader series consists of very deep, poorly drained soils formed in highly stratified alluvium and outwash derived from mixed sources. Schrader soils are on terraces and floodplains. Slopes range from 0 to 6 percent. The mean annual precipitation is about 8 inches and the mean annual air temperature is about 43 degrees F.

TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, frigid Cumulic Endoaquolls

TYPICAL PEDON: Schrader fine sandy loam - grassland. (Colors are for dry soil unless otherwise noted.)

A1--0 to 7 inches; grayish brown (10YR 5/2) fine sandy loam, very dark grayish brown (10YR 3/2) moist; strong fine granular structure; soft, very friable, nonsticky and nonplastic; slightly alkaline (pH 7.4); clear smooth boundary. (6 to 14 inches thick)

A2--7 to 33 inches; grayish brown (10YR 5/2) fine sandy loam stratified with lenses of loam, very dark grayish brown (10YR 3/2) moist; common medium distinct dark yellowish brown (10YR 3/4) moist redox concentrations and dark gray (2.5Y 4/1) moist redox depletions; very weak coarse subangular blocky structure; slightly hard, friable, nonsticky and slightly plastic; neutral (pH 7.2); gradual wavy boundary. (18 to 46 inches thick)

Cg--33 to 60 inches; gray (2.5Y 6/1) fine sandy loam stratified with lenses of loam, dark gray (2.5Y 4/1) moist; many large prominent dark yellowish brown (10YR 3/4) moist and light olive brown (2.5Y 5/3) moist redox concentrations; massive; slightly hard, very friable, nonsticky and slightly plastic; neutral (pH 6.8).

TYPE LOCATION: Rio Grande County, Colorado; approximately 200 feet east of the road in the SW1/4 Sec. 23, T. 40 N., R.4 E.

RANGE IN CHARACTERISTICS:

Mean annual soil temperature: 43 to 46 degrees F.

Mean summer soil temperature: 59 to 61 degrees F.

Particle size control section averages: 35 to 80 percent finer or coarser sand, 5 to 18 percent clay, and 0 to 15 percent rock fragments (mainly 1 to 10 inches in diameter).

Reaction: slightly acid to moderately alkaline in a majority of subhorizons in the control section.

Exchangeable Sodium Percentage (ESP): 0 to 15 percent in the control section, except that a few subhorizons exceed this range discontinuously in some pedons.


A horizon:

Hue: 5Y to 7.5YR

Value: 4 or 5 dry, 2 or 3 moist

Chroma: 1 to 3 dry or moist

Reaction: neutral to slightly alkaline.


C horizon:

Hue: 5Y to 7.5YR (matrix)

Value: 4 to 6, 3 or 4 moist (matrix)

Chroma: 1 or 2 (matrix)

COMPETING SERIES: These are the Chaffee (CO) and the Conway (CA) series. Chaffee soils have Bg horizons and a lithologic discontinuity to a sandy-skeletal layer. Conway soils have mean annual temperatures greater than 44 degrees F. and formed in alluvium influenced by volcanic ash.

GEOGRAPHIC SETTING: Schrader soils are on floodplains and low terraces. Slopes range from 0 to 6 percent. These soils formed in highly stratified alluvium and outwash derived from mixed sources. At the type location the average annual precipitation is 8 inches, but is up to 20 inches in other areas of the state. The soil moisture is controlled by a high water table that is within a few inches of the surface during much of the growing season. Mean annual temperature is 41 to 44 degrees F., and the mean summer temperature is 58 to 62 degrees F.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the LaJara and Vastine soils. LaJara soils have a mollic epipedon less than 24 inches thick and are calcareous. Vastine soils have a mollic epipedon less than 24 inches thick and are underlain by sand and gravel at depths of 20 to 40 inches.

DRAINAGE AND PERMEABILITY: Poorly drained; low runoff; moderate to rapid permeability. These soils have a high water table during much of the growing season.

USE AND VEGETATION: These soils are used principally as native pastureland or as native hay meadow. Principal native plants are cottonwood, willows, and grasses.

DISTRIBUTION AND EXTENT: San Luis Valley Area of south-central Colorado. LRR E, MLRA 51. The series is of small extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana

SERIES ESTABLISHED: Rio Grande County, Colorado, 1972.

REMARKS: Diagnostic horizons and features recognized in this pedon are:

Mollic epipedon: The zone from 0 to 33 inches (A1 and A2 horizons)

Cumulic feature: the irregular decrease in organic carbon is inferred from the stratified textures.

Endosaturation: from 7 to greater than 60 inches (A2 and Cg horizons) in normal years, based on redoximorphic features.

Keys to Soil Taxonomy: Series classified according to Eighth Edition, 1998.

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National Cooperative Soil Survey
U.S.A.