LOCATION LANDAVASO NMEstablished Series
TAXONOMIC CLASS: Fine-loamy over sandy or sandy-skeletal, mixed, superactive, mesic Aridic Argiustolls
TYPICAL PEDON: Landavaso sandy loam on a concave, southeast aspect alluvial fan of 3 percent rangeland. (Colors are for dry soil unless otherwise stated.)
A1--0 to 3 inches; brown (10YR 5/3) sandy loam; dark brown (10YR 3/3) moist; single grain; loose, nonsticky and nonplastic; few fine roots; 10 percent pebbles; neutral; clear smooth boundary. (2 to 4 inches thick)
A2--3 to 10 inches; brown (10YR 5/3) sandy loam, dark brown (10YR 3/3) moist; weak very fine subangular blocky structure; slightly hard, friable, slightly sticky and nonplastic; common very fine and fine roots; 5 percent pebbles; neutral; abrupt smooth boundary. (5 to 10 inches thick)
Bt1--10 to 17 inches; yellowish brown (10YR 5/4) gravelly sandy clay loam, brown (10YR 4/3) moist; moderate fine and weak fine subangular blocky structure; slightly hard, firm, slightly sticky and slightly plastic; common very fine and few fine roots; few thin clay films bridging sand grains; 20 percent pebbles; neutral; abrupt wavy boundary. (5 to 10 inches thick)
Bt2--17 to 27 inches; yellowish brown (10YR 5/4) gravelly sandy clay loam, dark yellowish brown (10YR 4/4) moist; moderate medium and fine subangular blocky structure; slightly hard, firm, slightly sticky and plastic; few fine and very fine roots; few thin clay films bridging sand grains and on pebbles; 25 percent pebbles; neutral; clear wavy boundary. (8 to 12 inches thick)
2C1--27 to 41 inches; yellowish brown (10YR 5/4) very gravelly loamy sand, dark yellowish brown (10YR 4/4) moist; single grain; loose, nonsticky and nonplastic; few very fine roots; 35 percent pebbles; neutral; gradual wavy boundary. (10 to 24 inches thick)
2C2--41 to 60 inches; brown (7.5YR 5/4) very gravelly coarse sand, brown (7.5YR 4/4) moist; single grain; loose, nonsticky and nonplastic; 5 percent cobbles and 40 percent pebbles; neutral. (5 to 20 inches thick)
TYPE LOCATION: Socorro County, New Mexico; about 27 miles west of Magdalena; 1.2 miles west of the turnoff to the H.H. Ranch Headquarters along the north side of U.S. 60, 50 feet west of marker 483 + 53.9 in the NE1/4 SW1/4 Section 20, T.2S., R.8 W.
RANGE IN CHARACTERISTICS:
Soil Moisture: Dry in all parts of the SMCS, the majority of the time, during May and June. Moist in some part of the SMCS, part of the time from July 1 to September. Aridic ustic moisture regime.
Thickness of mollic epipedon: 7 to l4 inches
Depth to the base of the Bt horizon: 20 to 32 inches
Depth to contrasting material: 20 to 32 inches
A horizon
Value: 4 or 5 dry
Rock fragments: 5 to l5 percent pebbles
B horizon
Value: 4 or 5 dry, 3 or 4 moist
Chroma: 3 or 4
Clay content: 20 to 35 percent
Sand content: more than 50 percent sand with more than 35 percent fine sand or coarser
Rock fragments: 0 to 5 percent cobbles and l5 to 25 percent pebbles by volume
2C horizon
Hue: 7.5YR or l0YR
Value: 5 through 7 dry, 4 through 6 moist
Chroma: 2 through 4
Texture: coarse sand, loamy coarse sand, loamy sand
Rock fragments: 0 to 5 percent cobbles and 35 to 55 percent pebbles by volume
COMPETING SERIES: The competing series are Altvan (NE), Atencio (CO), Eckley (CO), Gustspring (NM), Newlin (CO), Redridge (CO), Tuthill (SD), Wheatridge (CO) and Wolfar (WY) series. Altvan and Atencio soils are calcareous within 40 inch depths. Eckley soils have contrasting material above 20 inches. Gustspring soils have a calcic horizon. Newlin soils receive more than l5 inches annual precipitation and the SMCS is moist in some part, the majority of the time, during May and June. Redridge soils have hue of 5YR or redder in the Bt horizon. Tuthill soils have less than 35 percent coarse fragments in the contrasting layers. Wheatridge soils have less than 50 percent sand in the Bt and less than 35 percent fine sand or coarser. Wolfvar soils contain more than 35 percent clay in the argillic horizon.
GEOGRAPHIC SETTING: Landavaso soils are on alluvial fans and drainageways on the San Agustin Plains with slopes ranging from l to 5 percent. They formed in gravelly alluvium from rhyolitic tuffs and lavas. Elevation ranges from 6,900 to 7,200 feet. Average annual precipitation is l2 to l5 inches, with the majority falling as rain between July and September as convective storms. Average annual temperature ranges from 47 to 54 degrees F., and frost-free period is l20 to l60 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Augustine, Datil, Royosa, and Telescope soils. Augustine soils lack the mollic epipedon and is fine-loamy. Datin soils are fine-loamy and have a calcic horizon. Royosa soils are sandy. Telescope soils are coarse-loamy and lack the mollic epipedon.
DRAINAGE AND PERMEABILITY: Well drained; slow runoff; moderately permeable.
USE AND VEGETATION: The major use of this soil is livestock grazing. Native vegetation is blue grama, western wheatgrass, bottlebrush squirreltail, and fourwing saltbush.
DISTRIBUTION AND EXTENT: West central New Mexico. Landavaso soils are of slight extent. MLRA 35.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Socorro County, New Mexico, l984.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - the zone from the surface to a depth of l0 inches. (Al, A2 horizons)
Argillic hroizon - the zone from l0 to 27 inches. (Btl, Bt2 horizons)
Lithologic discontinuity - the occurrence of textural change at 27 inches.