LOCATION LARGO              NM
Established Series
Rev. CLC/LWH/WWJ
10/2006

LARGO SERIES


The Largo series consists of very deep, well drained soils that formed in loamy calcareous alluvium derived from redbed formations of Jurassic, Triassic, Permian and Pennsylvanian age. These soils are on channeled valley bottom terraces, alluvial fans and piedmont slopes. They have moderate to moderately slow permeability. Their slopes range from 0 to 5 percent. Average annual precipitation is about 8 to 12 inches. Average annual air temperature 59 to 65 degrees F.

TAXONOMIC CLASS: Fine-silty, mixed, superactive, calcareous, thermic Typic Torriorthents

TYPICAL PEDON: Largo silt loam --(All colors are for moist soil unless otherwise stated.)

A--0 to 4 inches; reddish brown (5YR 5/3) silt loam, dark reddish brown (5YR 3/3) moist; weak medium platy structure in the surface 1 inch and weak medium fine subangular blocky structure below; soft, friable, slightly sticky, and slightly plastic; common fine roots; many very fine and fine pores; strongly effervescent; common faint mycelia and few soft bodies of calcium carbonate; moderately alkaline; clear smooth boundary. (3 to 6 inches thick)

AC--4 to 20 inches; reddish brown (5YR 5/3) silt loam, reddish brown (5YR 4/3) moist; weak coarse prismatic structure parting to weak medium subangular blocky; slightly hard, friable, moderately sticky and moderately plastic; many fine roots; many very fine and fine pores; few widely spaced clusters of very fine insect casts; strongly effervescent with common faint mycelia and few soft bodies of calcium carbonate; few fine limestone pebbles; moderately alkaline; gradual boundary. (4 to 20 inches thick)

C1--20 to 47 inches; reddish brown (5YR 5/4) silt loam, reddish brown (5YR 4/4) moist; weak coarse subangular blocky structure; hard, friable, moderately sticky and moderately plastic; few fine roots; many very fine and fine pores; common faint mycelia and concretions of calcium carbonate; few fine limestone pebbles; strongly effervescent; moderately alkaline; abrupt wavy boundary. (20 to several feet thick)

C2--47 to 65 inches; reddish brown (5YR 5/4) loam, reddish brown (5YR 4/4) moist; massive; hard, friable, moderately sticky and moderately plastic; about 5 percent pebbles; strongly effervescent with calcium carbonate disseminated and as coatings on pebbles and as few fine concretions; moderately alkaline.

TYPE LOCATION: Eddy County, New Mexico; 1730 feet north and 75 feet west of the southeast corner of Sec. 29, T. 16 S., R. 28 E.; Latitude 32 degrees 53 minutes 24 seconds and Longitude 104 degrees 11 minutes 22 seconds.

RANGE IN CHARACTERISTICS:

Soil depth - greater than 60 inches.

Soil moisture - soil moisture control section is usually dry in all parts more than three fourth of the time (cumulative) that the soil temperature exceeds 41 degrees F. The driest period is from October through May. Typic aridic moisture regime.

Reaction - slightly to moderately alkaline.

Particle size control section ranges from 18 to 35 percent clay and less than 15 percent fine and coarser sand.

Calcium carbonate equivalent ranges from 0 to 15 percent
Depth to free carbonates - 0 to 20 inches

A horizon
Hue: 2.5YR through 5YR.
Value: 4 or 5 dry and 3 or 4 moist.
Chroma: 3 or 4.

AC horizon
Hue: 2.5YR through 7.5YR.
Value: 5 or 6 dry and 3 through 5 moist.
Chroma: 3 to 4.

C horizon
Hue: 2.5YR through 7.5YR.
Value: 5 or 6 dry and 3 through 5 moist.
Chroma: 3 to 4.
Texture: very fine sandy loam, silt loam, clay loam, or silty clay loam.

COMPETING SERIES: The Tome (NM) soils. The Tome soils have a hue of 10YR.

GEOGRAPHIC SETTING: The Largo soils are on valley bottoms, terraces, alluvial fans, and piedmont slopes. Slopes range from 0 to 5 percent. They formed in loamy calcareous alluvium derived from redbed formations of Jurassic, Triassic, Permian and Pennsylvanian age. Elevations range from 4000 to 5500 feet. The average annual precipitation ranges from 8 to 12 inches, much of which falls in summer in heavy thunderstorms of short duration. The average annual air temperature is about 59 to 65 degrees F. The frost free period is 180 to 210 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Arno, Berino, Jal, Palomas and Tome soils. The Arno soils have more than 35 percent clay in the series control section and irregular distribution of organic matter throughout. Berino and Palomas soils have argillic horizons than contain more than 15 percent fine and coarser sand. The Jal soils have calcic horizons within 20 inches of the surface.

DRAINAGE AND PERMEABILITY: Well drained. Runoff is medium and permeability is moderate to moderately slow.

USE AND VEGETATION: Primarily used for livestock grazing but where water is available the soil is used for irrigated cropland. Native vegetation is black grama, blue grama, sideoats grama, bush muhly, tobosa grass, vine mesquite, mesquite, and creosotebush.

DISTRIBUTION AND EXTENT: Southern New Mexico. This soil occurs in LRR-D, MLRA 42. The soil is of moderate extent

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

SERIES ESTABLISHED: Quay County, New Mexico, Eastern New Mexico reconnaissance survey, 1939

REMARKS: Diagnostic horizons and features recognized in this pedon are:

Ochric epipedon - The zone from the surface of the soil to a depth of 10 cm. (A horizon)

Entisol feature - lack of diagnostic horizon

Classified according to Soil Taxonomy Second Edition, 1999.


National Cooperative Soil Survey
U.S.A.