LOCATION BIEDELL                 CO

Established Series
JMY/GB/TWH
01/2012

BIEDELL SERIES

The Biedell series consists of very deep, somewhat poorly drained soils formed in alluvium from igneous rocks. Biedell soils are on old lakebeds and overflow depressional areas, and have slopes of 0 to 2 percent. The mean annual precipitation is about 7 inches and the mean annual temperature is about 41 degrees F.

TAXONOMIC CLASS: Clayey over sandy or sandy-skeletal, smectitic over mixed, frigid Aquic Natrargids

TYPICAL PEDON: Biedell clay loam, grassland. (Colors are for dry soil unless otherwise noted.)

E--0 to 3 inches; very pale brown (10YR 7/3) clay loam, brown (10YR 5/3) moist; moderate very thin platy structure parting to weak fine granules; soft, very friable, sticky, plastic; strongly effervescent; moderately alkaline; clear smooth boundary. (0 to 5 inches thick)

Btn1--3 to 9 inches; light yellowish brown (10YR 6/4) heavy clay loam, yellowish brown (10YR 5/4) moist; moderate medium columnar structure parting to moderate medium subangular blocks; very hard, firm, sticky, very plastic; many prominent clay films on faces of peds; strongly effervescent; very strongly alkaline; gradual smooth boundary. (4 to 10 inches thick)

Btn2--9 to 27 inches; light yellowish brown (10YR 6/4) heavy clay loam, moderate medium subangular blocky structure; very hard, firm; very sticky, very plastic; common distinct clay films on faces of peds; strongly effervescent; yellowish brown (10YR 5/4) moist; few medium and fine faint brown (7.5YR 5/2) and strong brown (7.5YR 5/8) moist, redox features; very strongly alkaline; gradual smooth boundary. (8 to 14 inches thick)

Bkn--27 to 32 inches; very pale brown (10YR 8/4) clay loam, light yellowish brown (10YR 6/4) moist; massive; very hard, friable; sticky, very plastic; calcium carbonate visible in seams, and large spots; violently effervescent; common fine prominent black (2.5Y 2.5/1) and strong brown (7.5YR 5/8) moist, redox features; very strongly alkaline; clear smooth boundary. (2 to 6 inches thick)

2C--32 to 60 inches; light brownish gray (10YR 6/2) gravelly sand, dark grayish brown (10YR 4/2) moist; single grained; 25 percent gravel; slightly effervescent; strongly alkaline.

TYPE LOCATION: Saguache County, Colorado; about 11 miles north of Center; about 1,900 feet south and 1,700 feet west of the northeast corner of Sec. 11, T. 42 N., R. 8 E. USGS Harrence Lake quad.; Lat. 37 degrees, 54 minutes, 09 seconds N., and Long. 106 degrees, 03 minutes, 32 seconds W.

RANGE IN CHARACTERISTICS:
Mean annual soil temperature: 43 to 46 degrees F
Mean summer soil temperature: 60 to 63 degrees F
Depth to lithologic discontinuity with the sandy 2C horizon: 20 to 35 inches
Depth to free carbonates: 0 to 12 inches
Depth to secondary accumulations of calcium carbonate, calcium sulfate, or more soluble salts: 12 to 30 inches, but such horizons are not strong enough to qualify for calcic, gypsic, or salic horizons.
Depth to endosaturation: 24 to 40 inches

Particle-size control section (weighted average):
Noncarbonate clay content: 35 to 50 percent
Sand content, fine sand or coarser: 5 to 25 percent

E horizon:
Hue: 7.5YR or 10YR
Value: 5 through 7 dry, 3 through 5 moist
Chroma: 2 through 4, dry or moist
Reaction: moderately alkaline or strongly alkaline
Gravel content: 0 to 15 percent
Exchangeable sodium percent: 15 to 60 percent, less than 15 percent in some pedons

Btn horizons:
Hue: 5Y through 7.5YR
Value: 5 through 7 dry, 4 through 6 moist
Chroma: 2 through 6, dry or moist
Redox features: common to many, are typically fine or medium, and prominent. Both bright and dull chroma redox features commonly are present.
Texture: clay or clay loam
Structure: typically columnar or prismatic in the upper part of the Bt horizon and subangular blocky in the lower part
Reaction: very strongly alkaline
Gravel content: 0 to 15 percent
Exchangeable sodium percent: 15 to 60 percent

Bkn horizon:
Hue: 5Y through 7.5YR
Texture: clay loam or sandy clay loam
Gravel content: 0 to 15 percent
Reaction: strongly alkaline or very strongly alkaline

2C horizon:
Texture: gravelly sand, sand
Gravel content: 0 to 30 percent

COMPETING SERIES: There are no known competing series in this family and subgroup. Closely related series are the Kerber, Hooper and San Luis soils. Kerber soils have coarse-loamy particle-size control section. Hooper soils lack the high water table and low chroma redox features in the solum. San Luis soils are fine-loamy over the sandy or sandy-skeletal 2C horizon and average less than 27 percent clay.

GEOGRAPHIC SETTING: Biedell soils are on old lakebed overflow depressional areas. Slopes are 0 to 2 percent. The soils formed in alluvium derived from volcanic and igneous rocks. Elevation: 7,500 to 8,000 feet. Annual precipitation is 6 to 9 inches. The mean annual temperature is 40 to 44 degrees F. Mean summer temperature is 59 to 62 degrees F.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Corlett and Hagga soils and the closely related Hooper soils. Corlett and Hagga soils do not have a natric horizon. Hooper soils do not have saturation above 40 inches.

DRAINAGE AND PERMEABILITY: Somewhat poorly drained; low runoff; very slow permeability; flooding is common in most places for short periods in most years.

USE AND VEGETATION: These soils are used for rangeland. Principal native plants are inland saltgrass, creeping wildrye, and Baltic rush.

DISTRIBUTION AND EXTENT: The San Luis Valley of Southcentral Colorado. The series is of moderate extent.

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

SERIES ESTABLISHED: Saguache County Area, Colorado, 1981.

REMARKS: Diagnostic horizons and features recognized are:
Ochric epipedon: from 0 to 3 inches (E horizon)
Natric horizon: from 3 to 27 inches. (Btn1, Btn2 horizons)
Secondary carbonate accumulations: from 27 to 32 inches (Bkn horizon)
Lithologic discontinuity: at 32 inches (upper boundary of the 2C horizon)
Endosaturation and redox features: in the 9 to 27 inch layer and below; this pedon is presumed to be have saturation but not aquic conditions (no chemical reduction)
Particle-size control section: from 3 to 23 inches (upper 20 inches of the natric horizon)

The 01/2012 revision changes the drainage class from poorly to somewhat poorly, and attempts to clarify the saturation characteristics. The original depth to saturation was loosely defined as "within a meter". This was revised to "24 to 40 inches" to be consistent with the Saguache Area published survey. It is unclear whether this saturation has accompanying chemical reduction, and would consequently be aquic conditions. At the current time, it is assumed chemical reduction is not significant above a depth of a meter. The 01/2012 revision removed the "g" suffix from the Btn2 and Bkn horizons. It remains unclear why the saturation depth was originally given as 2 to 3 feet in the Saguache report, yet redox features are described as shallow as 9 inches in the typical profile.

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National Cooperative Soil Survey
U.S.A.