LOCATION LOARC              NM
Established Series
Rev. CEM/TEH/CDL
11/2006

LOARC SERIES


The Loarc series consists of deep, well drained, moderately permeable soils that formed in alluvium. These soils are on alluvial fans with slopes ranging from 0 to 12 percent. Average annual precipitation is about 14 inches and the average annual air temperature is about 49 degrees F.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Aridic Argiustolls

TYPICAL PEDON: Loarc loamy sand--rangeland. (Colors are for dry soil unless otherwise noted.)

A1--0 to 7 inches; brown (10YR 5/3) loamy sand, dark brown (10YR 3/3) moist; weak fine granular structure; soft, very friable; nonsticky and nonplastic; common very fine and few fine roots; 5 percent pebbles; neutral; abrupt smooth boundary. (5 to 10 inches thick)

A2--7 to 14 inches; brown (10YR 4/3) loamy sand, very dark grayish brown (10YR 3/2) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; few very fine and fine roots; 5 percent pebbles; neutral; abrupt wavy boundary. (5 to 9 inches thick)

Bt--14 to 23 inches; brown (7.5YR 5/4) sandy clay loam, brown (7.5YR 4/4) moist; moderate fine and medium subangular blocky structure; hard, friable, sticky and plastic; few very fine and fine roots; few thin clay films in pores and bridging sand grains; 10 percent pebbles; neutral; clear wavy boundary. (9 to 21 inches thick)

C1--23 to 36 inches; brown (7.5YR 5/4) sandy loam, brown (7.5YR 4/4) moist; massive; hard, friable, slightly sticky and nonplastic; few very fine roots; 10 percent pebbles; slightly acid; clear wavy boundary. (9 to 20 inches thick)

C2--36 to 60 inches; reddish yellow (7.5YR 7/6) gravelly sandy loam, brown (7.5YR 5/4) moist; massive; hard, friable, slightly sticky and nonplastic; few very fine roots; 15 percent pebbles; slightly acid.

TYPE LOCATION: Socorro County, New Mexico; about 12 miles west of Magdalena; 1,250 feet west and 625 feet south of the northeast corner of section 29, T. 2 S., R. 6. W.

RANGE IN CHARACTERISTICS:

Thickness of the mollic epipedon: 10 to 19 inches

Depth to the base of the Bt: 19 to 40 inches

Rock fragments: 10 to 20 percent gravel

Depth to carbonates: 25 to 60 inches

Soil moisture: The soil moisture control section is not dry in all parts more than 50 percent of the time the soil temperature is above 41 degrees F., but is dry in some parts more than 60 percent of the time. It is moist in some part of the SMCS more than 40 days in the 120 days following the summer solstice. Aridic ustic moisture regime.

A horizon
Hue: 10YR
Value: 4 or 5 dry
Chroma: 2 or 3
Texture: loamy sand, sandy loam, or fine sandy loam.

Bt horizon
Hue: 10YR or 7.5YR
Value: 4 through 6 dry, 3 through 5 moist
Chroma: 2 through 6
Texture: sandy clay loam, clay loam or gravelly sandy loam
Clay content: averaging from 18 to 35 percent
Rock fragments: 10 to 20 percent
Reaction: neutral to moderately alkaline.

C horizon
Hue: 10YR or 7.5YR
Value: 5 through 8 dry, 4 through 7 moist
Chroma: 2 through 6
Texture: loamy sand, sandy loam, sandy clay loam or gravelly sandy loam
Coarse fragments: 0 to 25 percent pebbles
Reaction: slightly acid to strongly alkaline
Calcium carbonate equivalent: 0 to 14 percent. In some pedons, calcic horizons occur below 40 inches.

COMPETING SERIES: These are Ascalon (CO), Belfon (KS), Bresser (CO), Cedak (WY), Charklin (NV), Critchell (CO), Dagflat (UT), Datil (NM), Featherlegs (WY), Forgan (OK), Hargreave (WY), Harlan (WY), Hemingford (NE), Hiarc (NM), Kirtley (WY), Lavate (UT), Moskee (WY), Noden (WY), Palmer Canyon (WY), Recluse (WY), Satanta (KS), Shalona (CO), Sitcan (CO), Sugardee (WY), Wages (CO), and Wolf (WY) series.

Ascalon, Asparas, Capulin, Datil, Featherlegs, Gustsprings, Harlan, Kirtley, Palmer Canyon, Satanta, Sugardee, Wages, and Wolf soils have secondary carbonates in the Bt or have Bk horizons. Dagflat, Hargreave, Hiarc, Rosebud and Ryegate soils have bedrock within 40 inches. Critchell soils are gravelly throughout. Bresser soils have sandy C horizons. The Lavate soils are moist in some part of the soil moisture control section for less than 40 days in the 120 days following the summer solstice. Noden and Shalona soils have less than 10 percent rock fragment in the particle-size control section. Hemingford soils have free carbonates at 12 to 24 inch depths. In addition, Ascalon, Belfon, Bresser, Cedak, Critchell, Featherlegs, Forgan, Hargreave, Harlan, Hemingford, Kirtley, Moskee, Noden, Palmer Canyon, Recluse, Satanta, Sitcan, Sugardee, Wages and Wolf soils are in LRRs G & H are more moist in May and June.

GEOGRAPHIC SETTING: Loarc soils are on alluvial fans. Slopes are 0 to 12 percent. These soils formed in mixed alluvium. Elevations range from 6,300 to 8,100 feet. The average annual precipitation is about 12 to 15 inches and the average annual air temperature is about 47 to 54 degrees F. The average frost-free period is about 115 to 160 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Royosa, Telescope, and the competing Datil soils. Royosa and Telescope soils do not have mollic epipedons nor argillic horizons.

DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; moderate permeability.

USE AND VEGETATION: These soils are used primarily for grazing. The native vegetation of a pinyon juniper savannah with an understory of blue grama, dropseeds, Indian ricegrass, and bottlebrush squirreltail grasses.

DISTRIBUTION AND EXTENT: Central New Mexico. They are moderately extensive. MLRA 35.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona

SERIES ESTABLISHED: Catron County, New Mexico, 1982.


National Cooperative Soil Survey
U.S.A.