LOCATION WALKIBOUT NMEstablished Series
TAXONOMIC CLASS: Coarse-silty, mixed, superactive, calcareous, mesic Ustic Torriorthents
TYPICAL PEDON: Walkibout loam--on a convex side slope of a gulch sloping 65 percent to the west at 5,820 feet elevation--rangeland. (Colors are for dry soil unless otherwise noted. When described, the soil was dry from 0 to 80 inches and slightly moist below 80 inches.)
A--0 to 2 inches; brown (7.5YR 5/3) loam, brown (7.5YR 4/3) moist; moderate medium platy structure parting to weak fine granular; soft, very friable, slightly sticky and slightly plastic; few fine and few very fine roots; common very fine irregularly shaped pores; 5 percent gravel; strongly effervescent; moderately alkaline (pH 8.4); clear wavy boundary. (1 to 4 inches thick)
BCk--2 to 7 inches; light brown (7.5YR 6/3) fine sandy loam, brown (7.5YR 4/3) moist; weak medium subangular blocky structure; soft, very friable, slightly sticky and nonplastic; common medium, common fine, and common very fine roots; few very fine irregularly shaped pores; 10 percent gravel; strongly effervescent, secondary calcium carbonate segregated as few fine irregularly shaped coats on rock fragments; moderately alkaline (pH 8.4); clear wavy boundary. (0 to 5 inches thick)
C1--7 to 18 inches; light brown (7.5YR 6/4) very fine sandy loam, brown (7.5YR 4/4) moist; weak medium subangular blocky structure; soft, very friable, slightly sticky and nonplastic; few fine and common very fine roots; few very fine tubular pores; few thin strata of fine sandy loam and silt loam; strongly effervescent; moderately alkaline (pH 8.4); abrupt smooth boundary.
C2--18 to 25 inches; light brown (7.5YR 6/4) silt loam, brown (7.5YR 5/4) moist; weak coarse prismatic structure parting to weak medium subangular blocky; slightly hard, friable, moderately sticky and slightly plastic; few fine and common very fine roots; common very fine tubular pores; few laminae of very fine sandy loam; few 0.25 mm wide cracks; strongly effervescent; moderately alkaline (pH 8.2); clear smooth boundary.
C3--25 to 42 inches; light brown (7.5YR 6/3) silt loam, brown (7.5YR 4/3) moist; weak coarse prismatic structure parting to weak medium subangular blocky; moderately hard, firm, moderately sticky and moderately plastic; few very fine roots; few fine and common very fine tubular pores; few pieces of charcoal; common 0.5 to 1 mm wide cracks; strongly effervescent; moderately alkaline (pH 8.4); clear wavy boundary.
C4--42 to 49 inches; light brown (7.5YR 6/4) stratified fine sandy loam and gravelly coarse sand, brown (7.5YR 4/4) moist; massive and single grain; soft and loose, very friable and loose, slightly sticky and nonsticky, slightly plastic and nonplastic; few very fine roots; few very fine tubular pores; 5 to 20 percent gravel; strongly effervescent; moderately alkaline (pH 8.2); abrupt wavy boundary.
C5--49 to 55 inches; light brown (7.5YR 6/4) very fine sandy loam, brown (7.5YR 5/4) moist; massive; slightly hard, very friable, slightly sticky and nonplastic; few very fine roots; few fine and few very fine tubular pores; few thin strata of silt loam; strongly effervescent; moderately alkaline (pH 8.4); abrupt wavy boundary.
C6--55 to 72 inches; light brown (7.5YR 6/4) stratified loamy fine sand and gravelly coarse sand, brown (7.5YR 5/4) moist; massive and single grain; soft and loose, very friable and loose, nonsticky and nonplastic; few very fine roots; few thin strata of silt loam; 0 to 25 percent gravel; slightly and strongly effervescent; moderately alkaline (pH 8.2); abrupt smooth boundary.
C7--72 to 87 inches; light brown (7.5YR 6/4) stratified very fine sandy loam and loamy very fine sand, brown (7.5YR 5/4) moist; massive; soft, very friable, slightly sticky and nonplastic; strongly effervescent; moderately alkaline (pH 8.2); clear smooth boundary.
C8--87 to 120 inches; light brown (7.5YR 6/4) stratified silt loam and very fine sandy loam, brown (7.5YR 4/3) moist; massive; slightly hard and soft, friable and very friable, moderately sticky and slightly sticky, slightly plastic and nonplastic; strongly effervescent; moderately alkaline (pH 8.2). (Combined thickness of the C horizons is more than 80 inches.)
TYPE LOCATION: Santa Fe County, New Mexico; on the Pojoaque Indian Reservation about 1 mile northwest of Pojoaque; 800 feet north and 2,200 feet east of the southwest corner of section 6, T.19N., R.9E.; USGS Espanola 7.5 minute topographic quadrangle; Latitude 35 degrees 54 minutes 5 seconds North and Longitude 106 degrees 1 minute 42.5 seconds West, NAD 27.
RANGE IN CHARACTERISTICS:
Soil moisture - The soil moisture control section is intermittently moist in some part from July to October and December to March. The soils are driest in May and June. The soil moisture regime is torric (aridic) bordering on ustic.
Mean annual soil temperature - 52 to 54 degrees F.
Volcanic glass content: 5 to 15 percent in the coarse silt plus sand fraction
Lithology of rock fragments: granite, gneiss, schist, and sandstone
Cracks - none to few, 0.25 to 2 mm wide, typically in horizons or strata which are silt loam or silty clay loam in texture
Particle-size control section (weighted averages)
Silicate clay content: 8 to 18 percent
Fine sand or coarser content: 5 to 15 percent
Rock fragment content: 0 to 5 percent gravel
Mica content: 1 to 5 percent (by grain count)
Reaction - slightly alkaline to moderately alkaline in the surface; moderately alkaline to strongly alkaline in the underlying material
Calcium carbonate equivalent - 1 to 5 percent
Salinity, mmhos/cm - 0 to 2 in the surface and subsurface; 0 to 4 in the underlying material
Sodicity, SAR - 0 to 1 in the surface and subsurface; 0 to 4 in the underlying material
A horizon
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 3 or 4, dry or moist
Rock fragments: 0 to 10 percent gravel
BCk horizon
Value: 4 or 5 moist
Chroma: 3 or 4, dry or moist
Texture: fine sandy loam, very fine sandy loam, or silt loam
Rock fragments: 0 to 10 percent gravel
This horizon is too thin to qualify as a cambic horizon
upper C horizons
Hue: 5YR or 7.5YR
Value: 4 or 5 moist
Chroma: 3 or 4, dry or moist
Texture: very fine sandy loam, silt loam, or loam; most pedons have thin strata and laminae of silty clay loam; some pedons have few thin strata of fine sandy loam or lenses of gravelly coarse sand
Other features: some pedons have a weak grade of prismatic or subangular blocky structure in these horizons, but lack evidence of removal or accumulation of calcium carbonate to qualify for a cambic horizon; some pedons have few to common, relict redox concentrations of iron
lower C horizons
Hue: 5YR or 7.5YR
Value: 4 or 5 moist
Chroma: 3 or 4, dry or moist
Texture: stratified loamy very fine sand to silty clay loam; some pedons have few to common, thin strata, lenses, or subhorizons of fine sandy loam, loamy fine sand, gravelly loamy sand, or gravelly coarse sand;
Other features: some pedons have few to common, relict redox concentrations of iron
COMPETING SERIES: These are the Keota, Mitchell, and Truxton (T) series. Keota soils have soft bedrock between 20 and 40 inches. Mitchell soils are moist in some part of the soil moisture control section in May and June. Truxton soils have texture of silt loam in the particle-size control section, have hue of 10YR, have mean annual soil temperature of 57 to 59 degrees F., and occur on flood plains. In addition, all of these soils do not have significant amounts of mica in the silt and sand fractions.
GEOGRAPHIC SETTING: Walkibout soils are on backslopes of gulches. They formed in colluvium and alluvium derived from Tertiary micaceous sandstone, siltstone, mudstone, and fanglomerate. Slopes are 25 to 80 percent. Elevation ranges from 5,400 to 7,100 feet. The mean annual precipitation is 9 to 12 inches with about 45 percent falling as rain from high-intensity convective thunderstorms between July and September. The mean annual air temperature is 50 to 52 degrees F. The frost-free period is 150 to 170 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Innacutt, Koshare, and El Rancho soils. Innacutt soils are coarse-loamy, do not have ochric epipedons, and occur on inset fans and narrow flood plains. Koshare soils are coarse-loamy, have cambic horizons, and occur on toeslopes. El Rancho soils are fine-silty, have cambic horizons, and occur on toeslopes.
DRAINAGE AND PERMEABILITY: Well drained; high surface runoff; moderately rapid permeability.
USE AND VEGETATION: Walkibout soils are used for livestock grazing, wildlife habitat, and recreation. The historic climax vegetation is Indian ricegrass, galleta, western wheatgrass, fourwing saltbush, and winterfat. The ecological site is Limy (R036XB129NM).
DISTRIBUTION AND EXTENT: Walkibout 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. The name is coined.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to a depth of about 2 inches. (A horizon)
Particle-size control section - The zone from 10 to 40 inches (part of C1, C2, part of C3 horizons)
Series control section - The zone from 0 to 60 inches.
Taxonomic version: Classified according to Keys to Soil Taxonomy, Tenth Edition, 2006.