LOCATION BORREGO NMEstablished Series
TAXONOMIC CLASS: Clayey, mixed, active, frigid Lithic Haplustalfs
TYPICAL PEDON: Borrego sandy loam, ponderosa pine forest. (Colors are for dry soils unless otherwise noted.)
O1&O2--0 to 1 inch; undecomposed and decomposed needles, twigs, cones, etc.
E--1 to 4 inches; grayish brown (10YR 5/2) sandy loam, dark brown (10YR 3/3) moist; weak thin platy structure that parts to moderate fine crumb structure; loose, friable, nonsticky, nonplastic; many fine and very fine roots; many fine interstitial pores; neutral (pH 6.8); abrupt smooth boundary. (2 to 4 inches thick)
Bt1--4 to 7 inches; brown (7.5YR 5/4) clay loam, brown (7.5YR 4/4) moist; moderate fine and medium angular blocky structure; extremely hard, firm, sticky, plastic; many fine and medium roots; few fine pores; few thin clay films on ped faces; neutral (pH 7.2); clear smooth boundary. (3 to 6 inches thick)
Bt2--7 to 14 inches; brown (7.5YR 5/4) gravelly clay, brown (7.5YR 4/4) moist; strong fine and medium angular blocky structure; extremely hard, firm, very sticky, very plastic; few medium roots; few fine pores; few thin clay films on ped faces; about 15 percent by volume fine granitic gravel; neutral (pH 7.2); clear smooth boundary. (5 to 9 inches thick)
BC--14 to 19 inches; light yellowish brown (10YR 6/4) gravelly sandy clay loam; strong brown (7.5YR 5/6) moist; weak fine and medium angular blocky structure; very hard, firm, sticky, plastic; few roots; few very fine pores; about 20 percent by volume fine granitic gravel; neutral (pH 6.8); clear boundary. (3 to 6 inches thick)
R--19 inches; granite bedrock.
TYPE LOCATION: Santa Fe County, New Mexico, NW1/4 NW1/4, sec. 5, T.20N., R.11E.
RANGE IN CHARACTERISTICS:
Depth to bedrock: 14 to 20 inches
Content of stones and gravel: is less than 15 percent in the A horizon, but ranges from 15 to 30 percent in the subsoil.
Mean annual soil temperature: 32 degrees to 47 degrees F.
Soil moisture: The moisture control section is usually moist in all parts but may be seasonally dry in some parts for less than 3 months. The driest periods occur in the spring and fall months. Typic ustic moisture regime.
A2 horizon
Hue: 7.5YR or 10YR
Value: 4 through 6 dry and 2 through 4 moist
Chroma: 2 or 3.
B2t horizon
Hue: 7.5YR or 10YR
Value: 4 through 6 dry and 3 through 5 moist
Chroma: 3 or 4.
B3 horizon
Hue: 7.5YR or 10YR
Value: 5 through 7 dry and 4 through 6 moist
Texture: clay loam to clay (35 to 45 percent clay).
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Borrego soils are on strongly sloping to moderately steep upland slopes at elevations ranging from 8,000 to 9,000 feet. They formed in mixed gravelly materials of medium to fine textures that have weathered from Precambrian granite, gneiss and schist. At the type location, the mean annual precipitation is about 18 inches and the mean annual temperature ranges from 32 degrees to 47 degrees F. The climate is subhumid, continental. The precipitation occurs as snowfall in the winter and as rain in late June, July, August, and early September.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Chimayo, Cundiyo, Mirabal, Supervisor and Wilcoxson soils. Cundiyo and Wilcoxson soils lack bedrock within 20 inches and Chimayo, Mirabal, and Supervisor soils lack argillic horizons.
DRAINAGE AND PERMEABILITY: Well-drained; medium to rapid runoff; very slow permeability.
USE AND VEGETATION: Used for rangeland, timber production, watershed, and wildlife habitat. Dominant plants are Arizona fescue, Gambel oak and ponderosa pine, with scattered junipers.
DISTRIBUTION AND EXTENT: These soils are inextensive in the mountains of Northern New Mexico. MLRA 39 and 48A.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Santa Fe County (Santa Fe Area), New Mexico, 1970.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from 1 to 4 inches (E horizon)
Argillic horizon - the zone from 4 to 14 inches (Bt horizons)
Lithic contact - The boundary at 19 inches (R horizon)
Classified according to Keys to Soil Taxonomy Ninth Edition, 2003.