LOCATION PESO NM+WYEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Typic Haplustolls
TYPICAL PEDON: Peso very cobbly clay loam, range and wooded. (Colors are for dry soil unless otherwise noted.)
Oi--0 to 1 inch; undecomposed to partially decomposed leaves, needles, and woody twigs. (0 to 4 inches thick)
A--1 to 5 inches; very dark grayish brown (10YR 3/2) very cobbly clay loam, very dark brown (10YR 2/2) moist; moderate very fine granular structure; soft, very friable, slightly sticky, slightly plastic; many fine roots; many fine interstitial pores; about 10 percent channery fragments, 35 percent cobbles, and 10 percent stones; slightly alkaline; clear wavy boundary. (2 to 6 inches thick)
Bw--5 to 17 inches; dark grayish brown (10YR 4/2) very cobbly clay loam, very dark grayish brown (10YR 3/2) moist; moderate medium subangular blocky structure; hard, friable, sticky, plastic; common fine and medium roots; common fine and medium interstitial pores; about 10 percent channery fragments, 35 percent cobbles, and 10 percent stones; slightly calcareous; slightly alkaline; clear wavy boundary. (7 to 10 inches thick)
Bk--17 to 33 inches; brown (7.5YR 5/3) very cobbly clay loam, brown (7.5YR 4/3) moist; massive; hard, friable, sticky, slightly plastic; few medium to coarse roots; few fine interstitial and medium tubular pores; 10 percent gravel, 55 percent cobbles, 20 percent stones; few thin hard carbonate coatings on bottom sides of coarse fragments, common fine flecks of soft lime in the soil mass; moderately calcareous; moderately alkaline; gradual wavy boundary. (11 to 24 inches thick)
R--33 to 37 inches; limestone bedrock. The upper 6 inches is highly fractured.
TYPE LOCATION: Otero County, New Mexico; about 1/4 mile up Five Canyon on a south facing slope about 500 feet north of the road, near the SW corner of section 13, T.14S., R.12E.
RANGE IN CHARACTERISTICS:
Depth to bedrock: 20 to 40 inches. The upper 2 to 16 inches of bedrock is highly fractured.
Rock fragments in the control section: 35 to 85 percent limestone fragments increasing from the surface downward.
Average annual soil temperature: ranges from 39 to 47 degrees F.
Soil moisture: These soils are usually moist with the driest periods between April and June. Typic ustic moisture regime.
Reaction: neutral or slightly alkaline in the surface and moderately or strongly alkaline in the Bk horizon.
A horizon
Hue: 7.5YR or 10YR
Value: 3 or 4 dry, 2 or 3 moist
Chroma: 1.5 through 3 dry or moist
Organic matter content: 2 to 14 percent.
Calcium carbonate: It is noncalcareous to moderately calcareous.
Bw horizon
Rock fragments: 15 to 35 percent cobbles
Texture: clay loam, silty clay loam, silt loam to loam
Clay content: 18 to 35 percent clay
Hue: 5YR, 7.5YR or 10YR
Value: 4 or 5 dry, 2 or 3 moist
Chroma: 2 or 3 dry or moist.
Calcium carbonate: contains some calcium carbonate ranging in form from finely divided and nonvisible to a few medium soft mottles of mycelia in the upper part of the Bw horizon where a few thin patchy coatings are on the bottom of coarse fragments.
Bk horizon
Hue: 7.5YR or 10YR
Value: 4 through 7 dry, 3 through 5 moist
Chroma: 3 through 5 dry or moist.
Calcium carbonate: 6 to 15 percent ranging in form from finely divided and nonvisible to common soft mottles, soft concretions and mycelia with thin patchy caliche on coarse fragments.
Rock fragments: 70 to 95 percent limestone fragments.
COMPETING SERIES: These are the Ajuija (NM),
Finleypoint (MT),
Flott (MT),
Kutler (CO),
Labre (MT),
Perma (MT), Peso (NM),
Renegade (UT),
Sandia (NM),
Slimbutte (SD),
Subwell (MT),
Towave (UT),
Veatch (CO),
Vigilante (MT),
Walstead (MT),
Wanagan (ND) and
Wimper (MT) series.
Ajuija soils: are moderately deep to tuff bedrock
Finleypoint soils: very deep, have an albic horizon and are derived from glacial till.
Flott soils: have a calcic horizon.
Kutler soils: have a paralithic contact between 20 to 40 inches and are derived from granite. Kutler soils are in the 17 to 20 inch rainfall zone.
Labre soils: are very deep
Perma soils: deep
Peso soils: have Bk horizons with 6 to 15 percent calcium carbonate equivalent and formed in parent material derived from limestone
Renegade soils: have paralithic contact between 40 to 60 inches.
Sandia soils: have greater than 50 percent calcium carbonate equivalent in control section and contain 50 percent cobbles and stones in the control section.
Slimbutte soils: are calcareous at a shallow depth and fragmental below 40 inches.
Subwell soils: have a discontinuity at 10 to 20 inches, secondary carbonate accumulation and are non-skeletal above the discontinuity.
Towave soils: do not have a cambic horizon.
Veatch soils: derived from sedimentary parent material and are deep.
Vigilante soils: deep
Walstead soils: have calcic horizons
Wanagan soils: calcareous at shallow depths and contain a lithologic discontinuity at 12 to 20 inches.
Wimper soils: have calcic horizons and deep.
GEOGRAPHIC SETTING: The Peso soils are on strongly sloping to very steeply sloping and rolling mountains at elevations of 7,200 to 9,000 feet. The parent material is weathered mostly from limestone, siltstone, and limy soft shales. Peso soils occur in a dry subhumid climate. The mean annual precipitation is about 18 to 24 inches with a summer maximum. The average annual temperature is 37 to 45 degrees F. The Thornthwaite P-E Index is about 30 to 45.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Caballo, Gaines and Telefono soils. Caballo and Telefono soils have summer temperatures of less than 59 degrees F. Gaines soils have argillic horizons and lack coarse fragments in the control section.
DRAINAGE AND PERMEABILITY: Well drained; rapid runoff; moderately slow permeability.
USE AND VEGETATION: Range, woodland, recreation, watershed, and wildlife. Principal native vegetation is mountain brome, needle grasses, blue grama, sideoats grama, ponderosa pine, oakbrush, and some fir.
DISTRIBUTION AND EXTENT: Mountainous areas of south central New Mexico. The series is of moderate extent. MLRA 39. This soil has been mapped in Wyoming. Use in Wyoming should be discontinued.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Otero County (Mescalero, Apache Area), 1970.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Particle-size control section: The zone from 10 to 37 inches. (Bw and Bk horizons)
Mollic epipedon: 1 to 17 inches. (A and Bw horizons).
Cambic horizon: 5 to 17 inches (Bw horizon).
The assignment of the cation exchange capacity is inferred from lab data from similar soils in the surrounding area.
Classified according to Keys to Soil Taxonomy Tenth Edition, 2006.