LOCATION HORCADO NMEstablished Series
TAXONOMIC CLASS: Sandy-skeletal, mixed, mesic Aridic Calciustolls
TYPICAL PEDON: Horcado very gravelly coarse sandy loam--on a convex backslope sloping 20 percent to the southeast at 6,540 feet elevation--woodland. (Colors are for dry soil unless otherwise noted. When described, the soil was dry throughout.)
A--0 to 4 inches; brown (7.5YR 4/2) very gravelly coarse sandy loam, dark brown (7.5YR 3/2) moist; weak fine and medium granular structure; soft, very friable, slightly sticky and nonplastic; few fine and common very fine roots; 50 percent gravel; slightly effervescent; neutral (pH 7.0); clear smooth boundary. (2 to 4 inches thick)
Bk1--4 to 8 inches; brown (7.5YR 4/3) and brown (7.5YR 5/3) gravelly coarse sandy loam, dark brown (7.5YR 3/3) and brown (7.5YR 4/3) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and nonplastic; few coarse, few medium, common fine, and common very fine roots; few fine and common very fine irregularly shaped pores; 25 percent gravel; strongly effervescent, secondary calcium carbonate segregated in common fine and medium irregularly shaped coats on faces of peds and on rock fragments; moderately alkaline (pH 8.2); clear wavy boundary. (3 to 6 inches thick)
Bk2--8 to 17 inches; pink (7.5YR 7/3) and brown (7.5YR 4/3) very gravelly loamy coarse sand, brown (7.5YR 5/3) and brown (7.5YR 4/4) moist; moderate medium subangular blocky structure; slightly hard, very friable, slightly sticky and nonplastic; few coarse, few medium, few fine, and common very fine roots; few fine and few very fine irregularly shaped pores; krotovinas of very gravelly coarse sandy loam; 40 percent gravel; strongly to violently effervescent, secondary calcium carbonate segregated in common fine irregularly shaped coats on faces of peds and on rock fragments and few coarse irregular shaped coats on faces of peds; moderately alkaline (pH 8.4); abrupt irregular boundary. (5 to 10 inches thick)
BCk1--17 to 33 inches; yellowish red (5YR 5/6) and pink (5YR 7/3) very gravelly loamy coarse sand, yellowish red (5YR 4/6) and reddish brown (5YR 5/4) moist; weak medium subangular blocky structure; soft, very friable, slightly sticky and nonplastic; few coarse, few medium, few fine, and few very fine roots; 45 percent gravel; very slightly to strongly effervescent, secondary calcium carbonate segregated in few fine irregularly shaped coats on faces of peds and on rock fragments and few coarse irregular shaped masses; moderately alkaline (pH 8.0); abrupt irregular boundary. (9 to 16 inches thick)
BCk2--33 to 45 inches; white (7.5YR 8/1) and pink (7.5YR 7/4) very gravelly loamy sand, pink (7.5YR 7/4) and brown (7.5YR 5/4) moist; weak coarse subangular blocky structure; moderately hard, friable, slightly sticky and nonplastic; few coarse, few medium, few fine, and few very fine roots; few fine and few very fine irregularly shaped pores; large krotovinas of loose fill from above horizons; 35 percent gravel; very slightly to violently effervescent, secondary calcium carbonate segregated in common medium and coarse irregularly shaped coats on faces of peds and on rock fragments; moderately alkaline (pH 8.4); gradual wavy boundary. (0 to 12 inches thick)
BCk3--45 to 74 inches; pinkish white (7.5YR 8/2) and light brown (7.5YR 6/3) very gravelly loamy coarse sand, pink (7.5YR 7/3) and brown (7.5YR 5/4) moist; weak coarse subangular blocky structure; slightly hard, very friable, slightly sticky and nonplastic; few coarse, few medium, few fine, and few very fine roots; large krotovinas of loose fill from above horizons; 40 percent gravel; strongly to violently effervescent, secondary calcium carbonate segregated in common medium and coarse irregularly shaped coats on faces of peds and on rock fragments; moderately alkaline (pH 8.4); abrupt wavy boundary. (0 to 29 inches thick)
BCk4--74 to 88 inches; reddish brown (5YR 5/4) very gravelly coarse sand, reddish brown (5YR 4/4) moist; massive; slightly hard, friable, nonsticky and nonplastic; few very fine roots; small bodies of white volcanic ash; 45 percent gravel; noneffervescent in spots to strongly effervescent elsewhere, secondary calcium carbonate segregated in few medium and coarse irregularly shaped masses; strongly alkaline (pH 8.8); abrupt wavy boundary. (8 to 19 inches thick)
BCqk1--88 to 94 inches; light brown (7.5YR 6/4) gravelly sandy loam, brown (7.5YR 4/4) moist; massive; slightly hard, friable, slightly sticky and nonplastic; matrix is partially cemented in spots by secondary silica; 25 percent gravel; strongly effervescent, secondary calcium carbonate segregated in few fine irregularly shaped coats on rock fragments; strongly alkaline (pH 8.6); clear wavy boundary. (6 to 15 inches thick)
BCqk2--94 to 105 inches; pink (7.5YR 7/3) gravelly sandy loam, light brown (7.5YR 6/4) moist; massive; moderately hard, firm, slightly sticky and nonplastic; matrix is partially cemented in spots by secondary silica; 30 percent gravel; secondary calcium carbonate segregated in few fine irregularly shaped coats on rock fragments; violently effervescent; strongly alkaline (pH 8.8).
TYPE LOCATION: Santa Fe County, New Mexico; about 5.25 miles northwest of the old Horcado Ranch; 650 feet north and 1,650 feet west of the southeast corner of section 3, T.18N., R.8E.; USGS Horcado Ranch 7.5 minute topographic quadrangle; Latitude 35 degrees 48 minutes 52 seconds North and Longitude 106 degrees 4 minutes 37 seconds West, NAD 27.
RANGE IN CHARACTERISTICS:
Soil moisture - The soil moisture control section is moist in all parts during the 60 days following the winter solstice. It is moist in some part less than 40 percent of the time and moist in all parts less than 25 percent of the time when the soil temperature at 20 inches is above 41 degrees F. The soils are driest in May and June. The soil moisture regime is ustic bordering on aridic.
Mean annual soil temperature - 50 to 52 degrees F.
Thickness of mollic epipedon - 7 to 10 inches
Depth to calcic horizon - 7 to 10 inches
Depth to calcareous material (as visible secondary calcium carbonate) - 2 to 4 inches
Lithology of rock fragments: granite, gneiss, and schist
Organic matter content - 1 to 4 percent in the mollic epipedon
Reaction - neutral to slightly alkaline in the surface; slightly alkaline to moderately alkaline in the upper part of the substratum; moderately alkaline to strongly alkaline in the lower part of the substratum
Salinity, mmhos/cm - 0 to 1 in the surface and upper part of the substratum; 0 to 4 in the lower part of the substratum
Sodicity, SAR - 0 to 1 in the surface and upper part of the substratum; 0 to 4 in the lower part of the substratum
Particle-size control section (weighted averages)
Silicate clay content: 2 to 10 percent
Rock fragment content: 35 to 60 percent
A horizon
Value: 3 through 5 dry, 2.5 or 3 moist
Chroma: 2 or 3, dry or moist
Rock fragments: total range is 35 to 55 percent
35 to 50 percent gravel
0 to 5 percent cobbles
Bk1 horizon
Value: 4 or 5 dry
Chroma: 2 or 3, dry or moist
Texture: gravelly coarse sandy loam, gravelly sandy loam; some pedons have texture of very gravelly coarse sandy loam
Rock fragments: 20 to 35 percent gravel
Calcium carbonate equivalent: 2 to 5 percent
Bk2 horizon
Value: 5 through 7 dry, 4 through 6 moist
Chroma: 2 through 4, dry or moist
Texture: very gravelly loamy coarse sand or very gravelly coarse sandy loam; some pedons have texture of gravelly coarse sandy loam or gravelly sandy loam
Rock fragments: 35 to 55 percent gravel
Calcium carbonate equivalent: 10 to 15 percent
Other features: some pedons have thin subhorizons or zones of high calcium carbonate accumulation
Upper BCk horizons
Hue: 5YR or 7.5YR
Value: 5 through 8 dry, 4 or 5 moist
Chroma: 2 through 6, dry or moist
Texture: very gravelly loamy coarse sand or very gravelly loamy sand; some pedons have texture of very gravelly coarse sand;
Rock fragments: 35 to 55 percent gravel
Calcium carbonate equivalent: 2 to 5 percent
Other features: some pedons have thin subhorizons or zones of high calcium carbonate accumulation
Lower BCk horizons
Hue: 5YR or 7.5YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 4 or 6, dry or moist
Texture: very gravelly coarse sand or very gravelly loamy coarse sand
Rock fragments: 35 to 55 percent gravel
Calcium carbonate equivalent: 1 to 3 percent
Other features: some pedons have thin subhorizons or zones of high calcium carbonate accumulation
BCqk horizons
Hue: 5YR or 7.5YR
Value: 5 through 7 dry, 4 through 6 moist
Chroma: 4 through 8, dry or moist
Texture: gravelly sandy loam and very gravelly sandy loam
Rock fragments: 25 to 45 percent gravel
Calcium carbonate equivalent: 2 to 5 percent
Other features: some pedons have thin subhorizons or zones of high calcium carbonate accumulation
COMPETING SERIES: This is the Peetz(CO) series. Peetz soils have hue of 10YR or 2.5Y and are more moist in May and June.
GEOGRAPHIC SETTING: Horcado soils are on backslopes of eroded fan remnants. They formed in slope alluvium derived from Precambrian granite, gneiss, and schist. Slopes are 15 to 35 percent. Elevation ranges from 5,600 to 7,100 feet. The mean annual precipitation is 12 to 14 inches with about 45 percent falling as rain from high-intensity thunderstorms between July and September. The mean annual air temperature is 48 to 50 degrees F. The frost-free period is 140 to 160 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Latierra, Lamesilla, and Nazario soils. Latierra soils are coarse-loamy, have argillic horizons, and occur on toeslopes of eroded fan remnants. Lamesilla soils are coarse-loamy, have thick mollic epipedons, and occur on frequently flooded inset fans of eroded fan remnants. Nazario soils are fine-loamy over sandy or sandy skeletal, have ochric epipedons, and occur on adjacent narrow beveled summits and shoulders of eroded fan remnants.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained; medium surface runoff; moderately rapid permeability.
USE AND VEGETATION: Horcado soils are used for urban development, livestock grazing, and recreation. The historic climax vegetation is blue grama, sideoats grama, bottlebrush squirreltail, oak, twoneedle pinyon, and oneseed juniper. The ecological site is Pinus edulis-Juniperus monosperma/Quercus gambleii/Bouteloua gracilis(F036XB134NM).
DISTRIBUTION AND EXTENT: Horcado soils are of small extent on the southeastern Espanola Basin part of the Basin and Range province in northcentral New Mexico. The MLRA is 36.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Santa Fe County, New Mexico; Santa Fe Area Soil Survey Update; 2008. Horcado is a the name of a ranch.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to a depth of about 7 inches. (A and Bk1 horizons)
Calcic horizon - The zone from 8 to about 17 inches. (Bk2 horizon)
Particle-size control section - The zone from 10 to 40 inches (part of Bk2, BCk1, part of BCk2 horizon)
Series control section - The zone from 0 to 60 inches.
Classified according to Keys to Soil Taxonomy, Tenth Edition, 2006.