LOCATION CASITO NMEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, thermic, shallow Argic Petrocalcids
TYPICAL PEDON: Casito very gravelly sandy loam - rangeland. (Colors are for dry soil unless otherwise noted.)
Ek--0 to 2 inches; light brown (7.5YR 6/4) very gravelly sandy loam, brown (7.5YR 5/4) moist; generally massive with some weak medium platy structure in upper part; soft; few medium roots; effervescent; moderately alkaline; abrupt smooth boundary. (1 to 4 inches thick)
Btk1--2 to 6 inches; reddish brown (5YR 5/4) very gravelly sandy loam, reddish brown (5YR 4/4) moist; weak fine and very fine granular structure; loose; few fine roots; coatings of silicate clay on some sand grains and on tops of gravel; thin discontinuous calcium carbonate coatings on gravel, mainly on bottom; effervescent; moderately alkaline; clear wavy boundary. (3 to 8 inches thick)
Btk2--6 to 12 inches; light brown (7.5YR 6/4) very gravelly sandy clay loam, brown (7.5YR 5/4) moist; massive; soft, very friable; common fine roots; scattered lenses of reddish brown (5YR 5/4) and red (2.5YR 4/6), in which sand grains and gravel are discontinuously coated with clay; other sand grains and gravel coated with calcium carbonate; effervescent; moderately alkaline; abrupt smooth boundary. (4 to 8 inches thick)
Bkm--12 to 18 inches; pink (5YR 7/3) calcium carbonate-cemented hardpan, light reddish brown (5YR 6/4) moist; massive; extremely hard; a few lenses of light brown (7.5YR 6/4) soft loamy material contain the few roots in the horizon; effervescent; moderately alkaline; clear wavy boundary. (4 to 12 inches thick)
Bk1--18 to 28 inches; pinkish white (5YR 8/2) calcium carbonate-cemented material, light reddish brown (5YR 6/3) moist; massive; slightly hard and hard; pockets and small veins, about 1/4 to 1 inch in diameter of brown (7.5YR 5/4) moist, loamy material; few medium roots; effervescent; moderately alkaline; abrupt smooth boundary.
2Bk2--28 to 39 inches; light brown (7.5YR 6/4) sandy loam, brown (7.5YR 5/4) moist; weak medium subangular blocky structure; hard; few fine roots; an accumulation of calcium carbonate nodules and cylindroids occur near the middle of the horizon; effervescent; moderately alkaline; abrupt smooth boundary. (0 to 15 inches thick)
2Bk3--39 to 49 inches; light brown (7.5YR 6/4) very gravelly sandy loam, brown (7.5YR 4/4) moist; single grained; loose; very few soft aggregates of small gravel; few fine roots; patchy carbonate coatings mainly on underside of gravel; effervescent; moderately alkaline; gradual irregular boundary. (6 to 20 inches thick)
3C--49 to 60 inches; light brown (7.5YR 6/4) very gravely loamy sand, brown (7.5YR 4/4) moist; single grained; loose; patchy calcium carbonate coatings mainly on underside of gravel; effervescent; moderately alkaline.
TYPE LOCATION: Dona Ana County, (Desert Soil-Geomorphology Project), New Mexico; north bank of arroyo; 35 feet south of the Drippings Springs Road; in the NE1/4 of section 24, T.23 S., R.2 E.
RANGE IN CHARACTERISTICS:
Soil Moisture: Intermittently moist in some part of the soil moisture control section during December - April and for more than 20 days cumulative during July - September. Driest during May and June. Typic aridic soil moisture regime.
Soil Temperature: 58 to 66 degrees F.
Calcium carbonate: Effervescent throughout; some pedons are noneffervescent in the upper 3 inches
Depth to petrocalcic horizon: 8 to 20 inches
Organic carbon: Weighted average organic carbon of the upper 15 inches or of the upper 7 inches if the petrocalcic horizon is shallower than 15 inches but deeper than 7 inches, ranges from about 0.5 to 1.0 percent. Weighted average sand/clay ratios for these depths range from 1 to 5.
Rock fragments: More than 35 percent
A horizon
Hue: 5YR, 7.5YR
Value: 4 through 6 dry, 3 through 5 moist
Chroma: 2 through 4, dry or moist
Bt horizon
Hue: 2.5YR, 5YR
Value: 4 through 6 dry, 3 through 5 moist
Chroma: 3 through 6, dry or moist
Texture: sandy loam, sandy clay loam (15 to 35 percent clay)
Structure: Ranges from weak and moderate crumb to fine and medium subangular blocky structure.
Clay orientation: Sufficiently calcium carbonate-impregnated and mixed by roots or animals that orientation of silicate clay on sand grains and gravel has been obliterated in some parts of the horizon.
Bkm horizon
Hue: 5YR, 7.5YR, 10YR
Value: 7 through 9 dry, 5 through 7 moist
Chroma: 2 through 4, dry or moist
A laminar layer is present in the upper part in some pedons.
COMPETING SERIES: This is the Colorock (NV) and Sezna (NV) series. Colorock and Sezna soils are in the Mohave Desert (MLRA 30) receive mostly winter precipitation and are usually dry from April through November.
GEOGRAPHIC SETTING: The Casito soils are on alluvial fans and terraces. Slope is usually about 2 percent, ranging from about 1 to 5 percent. The soils formed in very gravelly sediments derived primarily from such igneous rocks as rhyolite andesite, in places with lesser amounts of sedimentary rocks. Mean annual precipitation ranges from 7 to 10 inches with a marked summer maximum. Mean annual air temperature is 60 to 68 degrees F. The frost-free period is 180 to 220 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Arizo, Delnorte, Nolam, Pinaleno, Terino, and Vado soils. Arizo soils do not have argillic and petrocalcic horizons. Vado soils have cambic horizons and do not have petrocalcic horizons. Terino soils are not effervescent in all parts of the argillic horizon. Nolam soils do not have a petrocalcic horizon.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderate permeability in the Bt horizons.
USE AND VEGETATION: Used for wildlife habitat and some areas for livestock grazing and others are idle. Vegetation is creosotebush and range ratany; in places, there are a few snakeweed, Yucca baccata, barrel cactus, and scattered clumps of fluffgrass and bush muhly.
DISTRIBUTION AND EXTENT: Southern New Mexico. The Casito soil is inextensive. MLRA is 42.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Dona Ana County, New Mexico; 1972.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from 0 to 2 inches (Ek horizon)
Argillic horizon - The zone from 2 to 12 inches (Btk1, Btk2 horizons)
Petrocalcic horizon - The zone from 12 to 18 inches (Bkm horizon)
Classified according to Soil Taxonomy Second Edition, 1999
This series represents an identified soil within the Desert Soil-Geomorphology Project, Las Cruces, New Mexico. The project was a study of soils and geomorphology in an arid and semi-arid environment. The series is extensively referenced in many documents, publications and thesis. Revision outside the project area is discouraged in order to preserve the historical concept for research.