LOCATION COSTILLA           CO
Established Series
Rev. GB/AJS/JWB
12/2008

COSTILLA SERIES


The Costilla series consists of very deep, somewhat excessively drained soils that formed in wind-reworked sandy alluvium derived from granite, gneiss, and mica schist. Costilla soils are on, alluvial fans, alluvial flats, valley side slopes and wind reworked portions of terraces. Slopes range from 0 to 20 percent. The mean annual precipitation is about 8 inches and mean annual temperature is about 43 degrees F.

TAXONOMIC CLASS: Sandy, mixed, frigid Typic Haplocalcids

TYPICAL PEDON: Costilla loamy sand, grassland. (Colors are for dry soil unless otherwise noted.)

A--0 to 6 inches; grayish brown (10YR 5/2) loamy sand, dark grayish brown (10YR 4/2) moist; moderate fine granular structure; very friable, soft, 5 percent gravel; slightly alkaline; clear smooth boundary. (4 to 8 inches thick)

Bw--6 to 24 inches; brown (10YR 5/3) gravelly loamy sand; brown (10YR 4/3) moist; very weak medium subangular blocky structure that parts to single grains; very friable, soft, 20 percent gravel; slightly alkaline; clear wavy boundary. (0 to 20 inches thick)

Bk--24 to 60 inches; very pale brown (10YR 7/3) gravelly sand, dark grayish brown (10YR 4/2) moist; single grained; loose; 30 percent gravel; visible secondary calcium carbonate occurring as nodules, and as coatings on sand and gravel; calcareous; moderately alkaline; gradual wavy boundary. (10 to 20 inches thick)

TYPE LOCATION: Alamosa County, Colorado; 500 feet south and 1,120 feet west of northeast corner of sec. 21, T.37N.R.9W.

RANGE IN CHARACTERISTICS:

Depth to calcic horizon: 10 to 40 inches.

Control section: 10 to 40inches with textures of gravelly loamy sand or gravelly sand.
Rock fragments: 15 to 35 percent and are mainly less than 3 inches in diameter and range from 1/2 to 10 inches in diameter.
Mean annual soil temperature: 41 to 46 degrees F.
Mean summer soil temperature: 59 to 63 degrees F.

A horizon:
Hue: 2.5Y through 7.5YR
Value: 4 through 8 dry, 3 through 7 moist
Chroma: 1 through 4
Calcium Carbonate equivalent: 0 to 5 percent
Reaction: neutral to moderately alkaline.

Bw horizon:
Hue: 2.5Y through 7.5YR
Value: 4 through 8 dry, 3 through 7 moist
Chroma: 1 through 4
Calcium Carbonate equivalent: 0 to 5 percent
Reaction: neutral to moderately alkaline.

Bk horizon:
Hue: 2.5Y through 7.5YR
Value: 5 through 7 dry, 4 though 6 moist
Chroma: 2 through 4
Calcium carbonate equivalent: 5 to 20 percent
Reaction: slightly to strongly alkaline
Calcium carbonate equivalent: 5 to 14 percent

COMPETING SERIES:
Grassy Butte and Space City soils: Do not have 15 to 35 percent rock fragments

GEOGRAPHIC SETTING:
Landform: , alluvial flats, alluvial fans, valley side slopes, and wind reworked portions of terraces
Slope: 0 to 20 percent
Parent material: sandy alluvium derived from granite, gneiss, and mica schist
Precipitation pattern: Precipitation peaks in July and August occurring mostly as intense summer thunderstorms.
Mean annual temperature: 41 to 46 degrees F
Frost-free period: 85 to 100 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the McGinty, Cososa and Space City soils.
McGinty soils have a coarse-loamy family and are well drained
Cososa soils have a coarse-loamy family
Space City soils do not have 15 to 35 percent rock fragments

DRAINAGE AND PERMEABILITY: Somewhat excessively drained; very low runoff; rapid permeability.

USE AND VEGETATION: These soils are used principally as native pastureland; however, in recent years they have been used under sprinkler irrigation for hay crops. Typical native vegetation is mainly rabbitbrush, blue grama, ring muhly, threeawn, and sand dropseed.

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

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

SERIES ESTABLISHED: Alamosa County, Colorado, 1974.

REMARKS: 8/01 reclassified this soil due to the presence of the calcic horizon. Removed well drained drainage class. Narrowed the range of MLRA's to 51.

ADDITIONAL DATA:
Laboratory sample number: S70CO023001

Taxonomic version: Tenth edition, 2006


National Cooperative Soil Survey
U.S.A.