LOCATION POJO NMEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, thermic Ustalfic Petrocalcids
TYPICAL PEDON: Pojo loamy fine sand - rangeland. (Colors are for dry soil unless otherwise noted.)
A--0 to 9 inches; reddish brown (5YR 5/4) loamy fine sand, reddish brown (5YR 4/4) moist; weak fine granular structure; soft, very friable, nonsticky and nonplastic; many fine and very fine roots; moderately alkaline; clear smooth boundary. (5 to 13 inches thick)
Bt--9 to 21 inches; reddish brown (5YR 5/4) fine sandy loam, reddish brown (5YR 4/4) moist; weak medium subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; common fine very fine and medium roots; common thin clay films on faces of peds; moderately alkaline; clear wavy boundary.
Btk--21 to 25 inches; light reddish brown (5YR 6/4) fine sandy loam, reddish brown (5YR 5/4) moist; weak medium subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; few fine very fine and many medium roots; common thin clay films on faces of peds; violently effervescent; few fine calcium carbonate accumulations; moderately alkaline; abrupt wavy boundary. (Combined thickness of the Bt horizons is 15 to 27 inches.)
Bkm--25 inches; petrocalcic horizon.
TYPE LOCATION: DeBaca County, New Mexico; 150 feet north and 2,300 feet west of the southeast corner, sec. 21, T. 1 S., R. 28E.
RANGE IN CHARACTERISTICS:
Depth to a petrocalcic horizon ranges from 20 to 40 inches.
Soil Moisture: Intermittently moist in some part of the soil moisture control section June through September and December through March.
Soil Temperature: 59 to 63 degrees F.
A horizon:
Hue: 5YR or 7.5YR
Value: 4 to 6 dry, 3 to 5 moist
Chroma: 3 to 6
Texture: loamy fine sand or fine sandy loam
Reaction: neutral to moderately alkaline
Bt horizon:
Hue: 2.5YR, 5YR or 7.5YR
Value: 4 to 6 dry, 3 to 5 moist
Chroma: 4 to 8
Calcium carbonate equivalent: less than 15 percent
Reaction: neutral to moderately alkaline
COMPETING SERIES: There are no competing series. Similar soils are Douro, Hilken, Jerag, Sharvana, and Wickett. Douro soils contain greater than 18 percent clay in the control section and have less organic matter. Hilken soils contain 18 to 35 percent clay in the particle size control section. Jerag and Sharvana soils are less than 20 inches to a petrocalcic horizon. Wickett soils have mean annual soil temperature from 64 to 70 degrees F.
GEOGRAPHIC SETTING: Pojo soils are on mesas and hillslopes. Slope ranges from 0 to 5 percent. The soil developed in eolian and alluvial material of mixed origin. Mean annual temperature ranges from 58 to 60 degrees F, and the mean annual precipitation ranges from 12 to 15 inches. The frost-free period ranges from 180 to 200 days and elevation ranges from 3,900 feet to 5,300 feet.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Berwolf, Chispa, Kolar, Redona, Roswell, and Neso soils. Berwolf, Chispa, Redona, and Roswell soils are deep. Kolar and Neso soils are shallow to a petrocalcic horizon.
DRAINAGE AND PERMEABILITY: Well drained. Permeability of the soil material is moderately rapid above a very slowly permeable petrocalcic horizon. Runoff is negligible on slopes less than 1 percent, low on 1 to 3 percent slopes, and medium on 3 to 5 percent slopes.
USE AND VEGETATION: These soils are used primarily for livestock grazing. Present vegetation is primarily sand bluestem, little bluestem, sand dropseed, sand sage and skunk bush.
DISTRIBUTION AND EXTENT: East-central New Mexico, moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: DeBaca County, New Mexico, 1983.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon: 0 to 9 inches. (A horizon). When values are low, chromas are too high to meet the requirements of a mollic epipedon.
Argillic horizon: 9 to 25 inches. (Bt horizons)
Petrocalcic horizon: Indurated calcium carbonate at 25 inches. (Bkm
horizon)