LOCATION CROFTSHAW NMEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive Ustic Argicryolls
TYPICAL PEDON: Croftshaw loam - rangeland. (Colors are for dry soil unless otherwise noted.)
A--0 to 8 inches; brown (10YR 4/3) loam, very dark grayish brown (10YR 3/2) moist; moderate fine granular structure; soft, friable, slightly sticky and slightly plastic; few medium and fine roots; few very fine and fine interstitial pores; 5 percent pebbles; slightly acid; clear smooth boundary. (8 to 15 inches thick)
Bt1--8 to 14 inches; brown (10YR 4/3) clay loam, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; hard, firm, sticky and plastic; few fine and common very fine roots; few fine and common very fine tubular pores; common moderately thick clay films on faces of peds; 5 percent pebbles; moderately acid; clear wavy boundary. (5 to 24 inches thick)
Bt2--14 to 28 inches; brownish yellow (10YR 6/6) clay loam, dark yellowish brown (10YR 4/4) moist; weak fine and medium subangular blocky structure; hard, firm, sticky and plastic; few fine and very fine roots; few fine and very fine tubular pores; common thin clay films on faces of peds; few sand-size glass shards; 10 percent pebbles; moderately acid; gradual wavy boundary. (0 to 18 inches thick)
2C--28 to 60 inches; very pale brown (10YR 7/3) sandy loam, brown (10YR 5/3) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; few very fine roots; few very fine tubular pores; few sand-size glass shards; 10 percent pebbles; slightly acid.
TYPE LOCATION: Rio Arriba County, New Mexico; approximately 15.7 miles east and 5.3 miles south of Chama; New Mexico state plane coordinates 2,119,060 feet north and 485,135 feet east; 106 degrees, 18 minutes, 02 seconds west longitude; 36 degrees, 49 minutes, 20 seconds north latitude.
RANGE IN CHARACTERISTICS:
Soil Moisture: The soil is moist in some parts of the soil moisture control section November through May and July through September.
Mean Annual Soil Temperature: 37 to 39 degrees F.
Summer Soil Temperature: 47 to 52 degrees F.
Reaction: slightly acid to moderately acid.
Thickness of mollic epipedon: 8 to 15 inches.
Particle-size control section: 27 to 35 percent clay, less than 40 percent sand.
A horizon - Value: 3 or 4 dry, 2 or 3 moist.
Chroma: 2 or 3.
Coarse Fragments: 0 to 10 percent pebbles.
Bt horizon - Value: 4 to 6 dry, 3 to 5 moist.
Chroma: 3 to 6.
Coarse fragments: 5 to 15 percent pebbles on a weighted average.
C horizon - Value: 6 or 7 dry, 5 or 6 moist.
Chroma: 3 to 6.
Texture: clay loam or sandy loam.
Coarse fragments: 5 to 15 percent pebbles on a weighted average.
COMPETING SERIES: These are the Amsden(WY), Buffork(WY), Cific(WY), Coldsprings(T)(CO), Croydon(UT), Dra(ID), Gebson(T)(CO), Gelkie(CO), Hourglass(UT), Inchau(WY), Kezar(CO), Kittredge(CO), Leavitt(WY), Lucky(CO), Lymanson(WY), Lyonman(CA), Michelson(MT), Miracle(CO), Monad(MT), Monida(T)(ID), Morset(CO), Mult(UT), Newlands(CA), Oro Fino(MT), Passcreek(WY), Philipsburg(MT), Primeaux(NV), Rainbolt(T)(WY), Rammel(ID), Shotgun(T)(ID), Slacks(T)(ID), Swede(ID), Tingey(UT), Tripit(WY), Troutdale(CO), Wellsville(CO), Woosley(WY), and Youga(CO) series. Amsden, Dra, Gelkie, Leavitt, Lymanson, Michelson, Monida, Morset, Oro Fino, Passcreek, Philipsburg, Rainbolt, Rammel, Tingey, Wellsville, and Woosley soils have a horizon with calcium carbonate accumulations. Buffork, Cific, Inchau, Kezar, Lucky, Lymanson, Miracle, Mult, Newlands, Passcreek, Primeaux, Rammel, Shotgun, Slacks, Tripit, Troutdale, and Woosley soils are 20 to 40 inches deep to a lithic or paralithic contact. Coldsprings soils have a Bt horizon with a hue of 5YR or redder. Croydon soils have an E horizon and mean annual soil temperature greater than 39 degrees F. Gebson and Kittredge soils have more than 40 percent sand in the particle-size control section. Hourglass soils are dry during the late summer and average more than 15 percent rock fragments in the Bt horizon. Lyonman, Swede and Youga soils are dry more than 45 consecutive days in the summer. Monad soils have Bt horizons more than 60 inches deep and are moist during late spring and early summer.
GEOGRAPHIC SETTING: Croftshaw soils formed in colluvium derived dominantly from metamorphic rock on mountain sideslopes, rolling hills and valley sides. Slopes range from 3 to 20 percent. The mean annual precipitation is 30 to 35 inches and the mean annual temperature is 35 to 37 degrees F. Elevation ranges from 9,500 to 10,400 feet and the frost-free period is 50 to 70 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bywell, Crubas, Ess, and Gromes series. Bywell, Ess, and Gromes soils have more than 35 percent rock fragment. Crubas soils have a high water table.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderately slow permeability.
USE AND VEGETATION: Croftshaw soils are used for livestock grazing and wildlife habitat. The present vegetation is subalpine grassland, including Arizona fescue, Thurber fescue, Columbia needlegrass, mountainmuhly, pine dropseed and shrubby cinquefoil.
DISTRIBUTION AND EXTENT: North-central New Mexico. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Rio Arriba County, New Mexico, 1989. The series name is coined.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - the zone from the surface of the soil to a depth of 14 inches (A horizon).
Argillic horizon - the zone from about 8 to 28 inches (Bt horizon).