LOCATION DEKAIRU MP PBEstablished Series
TAXONOMIC CLASS: Ashy, amorphic, isohyperthermic Humic Ustivitrands
TYPICAL PEDON: Dekairu fine sandy loam, on a west facing, 30 percent slope in an area dominated by short grasses with widely dispersed small groves of trees, at an elevation of 98 meters (320 feet). (Colors are for moist soil unless otherwise noted. When described on June 4, 1999 the soil was moist throughout.)
A--0 to 5 cm (0 to 2 inches); very dark grayish brown (2.5Y 3/2), ashy fine sandy loam, dark grayish brown (2.5Y 4/2), dry; weak medium subangular blocky and weak fine subangular blocky structure; soft, friable, nonsticky, nonplastic; 10 percent subangular 2 to 5 millimeter (.08 to .20 inches) cinder fragments; moderately acid, pH 5.8 by 1:1 H2O; abrupt wavy boundary. 3 to 31 centimeters thick (1 to 12 inches)
2AC--5 to 10 cm (2 to 4 inches); very dark grayish brown (2.5Y 3/2), extremely gravelly ashy fine sandy loam; massive; loose, loose, nonsticky, nonplastic; 60 percent subangular 2 to 75 millimeter (.08 to 3 inches) cinder fragments; slightly acid, pH 6.3 by 1:1 H2O; abrupt wavy boundary. 0 to 13 centimeters thick (0 to 5 inches). Lab sample # 00P1288
3A--10 to 23 cm (4 to 9 inches); very dark grayish brown (2.5Y 3/2), gravelly ashy loam; weak fine subangular blocky structure; soft, friable, nonsticky, nonplastic; weakly smeary; 20 percent subangular 2 to 75 millimeter (.08 to 3 inches) cinder fragments; slightly acid, pH 6.5 by 1:1 H2O; clear wavy boundary. 0 to 23 centimeters thick (0 to 9 inches)
4A--23 to 38 cm (9 to 15 inches); very dark brown (10YR 2/2), ashy loam; weak fine subangular blocky structure; soft, friable, nonsticky, nonplastic; moderately smeary; 20 percent spherical 2 to 20 millimeter (.08 to 0.8 inches) very weakly cemented tuff masses; 10 percent subangular 2 to 5 millimeter (.08 to .20 inches) cinder fragments; neutral, pH 6.9 by 1:1 H2O; abrupt wavy boundary. 0 to 30 centimeters thick (0 to 12 inches)
5Bw--38 to 56 cm (15 to 22 inches); lithochromic brown (10YR 4/3), ashy loamy fine sand; weak medium subangular blocky and weak fine subangular blocky structure; soft, friable, nonsticky, nonplastic; weakly smeary; 25 percent angular very weakly cemented tuff masses; slightly alkaline, pH 7.4 by 1:1 H2O; clear wavy boundary. 15 to 38 centimeters thick (6 to 15 inches)
5BC--56 to 69 cm (22 to 27 inches); lithochromic olive brown (2.5Y 4/3), ashy loamy fine sand, light olive brown (2.5Y 5/3), dry; weak medium subangular blocky and weak fine subangular blocky structure; soft, friable, nonsticky, nonplastic; 1 percent subangular 2 to 20 millimeter (.08 to .80 inches) cinder fragments; alkaline, pH 7.6 by 1:1 H2O; abrupt irregular boundary. 0 to 25 centimeters thick (0 to 10 inches)
6Cr--69 to 97 cm (27 to 38 inches); lithochromic dark grayish brown (2.5Y 4/2) tuff bedrock.
TYPE LOCATION: Island of Pagan, Commonwealth of the Northern Marianas, approximately 3000 feet southeast of the weather station, lat. 18 degrees, 07 minutes and 8.18 seconds N., long. 145 degrees, 45 minutes, and 38.09 seconds E., NAD83, GPS/PLGR.
RANGE IN CHARACTERISTICS:
The soil moisture control section is moist in some part from July through November and much drier from December through June.
Depth to paralithic contact: 58 to 102 centimeters (27 to 38 inches)
Depth to tuff masses: 23 to 69 centimeters (9 to 27 inches)
Particle-size control section (weighted average):
Rock fragments: 5 to 30 percent gravel cinders
Pararock fragments: 5 to 20 percent tuff masses
A horizons:
Hue: 7.5YR, 10YR or 2.5Y
Value: 2 or 3
Chroma: 1 or 2
Texture: non-gravelly to extremely gravelly ashy coarse sands to ashy loams
Rock fragments: 12 to 65 percent gravel cinders
Reaction: moderately acid to neutral
B horizon:
Hue: 10YR or 2.5Y
Value: 2 to 4
Chroma: 1 to 4
Texture: non-gravelly to very gravelly ashy coarse sands to ashy silt loams
Rock fragments: 0 to 30 percent gravel cinders
Reaction: neutral to slightly alkaline
Seasonally cemented 2B horizons occur in some pedons between 35 and 100 centimeters (14 to 40 inches(
COMPETING SERIES: There are no other soils in the same family.
GEOGRAPHIC SETTING:
Parent material: basaltic and andesitic volcanic ash and cinders
Landform: dissected backslopes of coalescent remnant caldera rims and cinder covered `a`a lava plains
Slopes: 0 to 50 percent
Elevation: 3 to 250 meters (10 to 820 feet)
Mean annual temperature: 26 to 30 degrees C (79 to 86 degrees F)
Mean annual precipitation: 1778 to 2286 millimeters (70 to 90 inches)
Precipitation pattern: Monsoonal characterized by a wet season from July through November when moderate to torrential rains occur, and a dry season with substantially less precipitation from December through June.
Frost-free period: 365 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Shomoshon soils. Shomoshon soils have a skeletal family texture.
DRAINAGE AND PERMEABILITY: Well drained, low to high runoff, and moderate permeability.
USE AND VEGETATION: These soils are used for wildlife habitat. Native and naturalized vegetation includes short grasses, coconut palms, hibiscus, and mango trees.
DISTRIBUTION AND EXTENT: Northern Mariana Islands. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES PROPOSED: Island of Pagan, Commonwealth of the Northern Mariana Islands, 1999.
REMARKS:
Diagnostic horizons and features recognized in this pedon are: Ochric epipedon, Andic soil properties, Paralithic contact.
Particle-size control section: The zone from 0 to 69 centimeters (0 to 27 inches).
Ochric epipedon: The zone from 0 to 38 centimeters (0 to 15 inches).
Paralithic contact: The contact with volcanic tuff at 69 centimeters (27 inches). (Cr horizon)
Ustic moisture regime.
Taxonomic Version: Second edition Soil Taxonomy, 1999
ADDITIONAL DATA: National Soil Survey Laboratory sample # 99MP090-081