LOCATION ALAELOA HI
Established Series
Rev. JVP/CWS/SN/HI/MRK
07/2019
ALAELOA SERIES
The Alaeloa series consists of deep and very deep, well drained soils that formed in residuum weathered from basic igneous rock. Alaeloa soils are on low mountain slopes and have slopes of 0 to 35 percent. The mean annual rainfall is about 1219 millimeters (48 inches), and the mean annual temperature is about 22 degrees C. (72 degrees F.)
TAXONOMIC CLASS: Very-fine, parasesquic, isohyperthermic Ustic Palehumults
TYPICAL PEDON: Alaeloa silty clay--pasture. (Colors are for moist soil unless otherwise noted. All textures are apparent field textures.)
Ap--0 to 25 centimeters (0 to 10 inches); dark reddish brown (5YR 3/3) silty clay, reddish brown (5YR 4/3) dry; strong very fine and fine subangular blocky structure; hard, firm, moderately sticky and moderately plastic; many very fine, fine, and medium roots; many very fine and fine irregular and tubular pores; common worm holes and casts; some dark red material from B horizon mixed by cultivation; slightly effervescent with hydrogen peroxide; strongly acid (pH 5.4); abrupt wavy boundary. (23 to 25 centimeters {9 to 10 inches} thick)
Bt1--25 to 46 centimeters (10 to 18 inches); dark red (2.5YR 3/6) silty clay, red (2.5YR 4/6) dry; strong very fine subangular blocky structure; hard, friable, moderately sticky and moderately plastic; many roots; common very fine, fine, and medium tubular pores; few worm holes and casts; thin continuous clay films on peds; very strongly acid (pH 5.0); clear wavy boundary. (15 to 25 centimeters {6 to 10 inches} thick)
Bt2--46 to 74 centimeters (18 to 29 inches); dark red (2.5YR 3/6) silty clay, red (2.5YR 4/6) dry; strong very fine subangular blocky structure; hard, friable, moderately sticky and moderately plastic; many very fine roots, few fine tubular pores; thin continuous dark red and dark brown clay films on peds; very strongly acid (pH 4.8); gradual wavy boundary. (23 to 33 centimeters {9 to 13 inches} thick)
Bt3--74 to 122 centimeters (29 to 48 inches); coarse pattern of red (10R 4/6), dark red (2.5YR 3/6), and dark reddish brown (2.5YR 3/4) silty clay, red (10R 5/6) and red (2.5YR 4/6) dry; strong very fine and fine subangular blocky structure; hard, friable, moderately sticky and moderately plastic; few fine roots; many very fine and common fine tubular pores; thick continuous dark red clay films in vertical cracks; continuous films on peds; some granular material on peds; few soft rock fragments; very strongly acid (pH 4.9); clear wavy boundary. (46 to 66 centimeters {18 to 26 inches} thick)
Bt4--122 to 147 centimeters (48 to 58 inches); red (2.5YR 4/6) silty clay, red (2.5YR 4/6) dry; strong very fine and medium subangular blocky structure; hard, friable, moderately sticky and moderately plastic; few fine roots; many very fine and fine tubular pores; thick continuous clay films on peds; weak slickensides; many black specks; many highly weathered soft rock fragments; very strongly acid (pH 4.8). (20 to 30 centimeters {8 to 12 inches} thick)
C--147 to 178 centimeters (58 to 70 inches); red (2.5YR 4/6) stony silty clay.
TYPE LOCATION: Island of Oahu, Honolulu County, Hawaii; from the junction of Kailua Road and Kalanianaole Highway near Olomana, 2.1 miles southeast toward Waimanalo along the old highway to the entrance of a pasture on the west side of the highway; l00 feet west of the old highway. Koko Head Quadrangle - 21 degrees 21 minutes 38.65 seconds north latitude and 157 degrees 44 minutes 17.04 seconds west longitude (WGS84).
RANGE IN CHARACTERISTICS: Depth to the soft highly weathered rock ranges from 101 (40 inches) to more than 152 centimeters (60 inches). Elevations between 30 and 457 meters (100 and 1500 feet) may be isothermic.
The A horizon has hue of 5YR or 2.5YR, and moist value and chroma of 2 or 3.
The Bt horizon has hue of 2.5YR or 10R, value of 2 through 5 moist or dry and chroma of 6 through 8 dry, and 4 through 6 moist. Texture ranges from silty clay to silty clay loam. There are few to many slickensides and organic stains.
COMPETING SERIES: This is the
Ioleau series. Ioleau soils have an ochric epipedon; and, the A horizon has hue of 7.5YR or 10YR and is silty clay loam.
GEOGRAPHIC SETTING: Alaeloa soils formed in residuum weathered from basic igneous rock on low elevation mountain slopes at elevations from 0 to 457 meters (0 to 1,500 feet). Slopes range from 0 to 35 percent. Median annual rainfall is 889 to 1,524 millimeters (35 to 60 inches). Average January temperature is about 21 degrees C. (70 degrees F.), average July temperature is about 24 degrees C. (75 degrees F.), and average annual temperature is about 22 degrees C. (72 degrees F.) Annual pan evaporation is 1,524 to 1,778 millimeters (60 to 70 inches).
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Honolua,
Kahana,
Kaneohe,
Lolekaa, and
Papaa soils. Honolua soils have 5YR or 7.5YR hue in the Bt horizon. Kahana soils do not have an argillic horizon. Kaneohe soils have weak structure in the upper part of the argillic horizon and thin patchy clay films throughout the B horizon. Lolekaa soils have 10YR hue throughout the solum and thick continuous clay films in the upper part of the argillic horizon. Papaa soils have clay texture in the control section and distinct slickensides in the C horizon.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; slow to very rapid runoff depending on slope; saturated hydraulic conductivity is high..
USE AND VEGETATION: Used mainly for pasture. A small acreage is used for growing truck crops and orchards. Vegetation is guava (Psidium guajava), Java plum (Eugenia cumini), christmasberry (Schinus terebinthifolius), Japanese tea (Cassia leschenaultiana), sensitive plant (Mimosa pudica), hilograss (Paspalum conjugatum), and honohono (Commelina diffusa).
DISTRIBUTION AND EXTENT: Islands of Oahu, Maui, and Molokai. The series is of small extent, comprising about 8,700 acres.
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Davis, California.
SERIES ESTABLISHED: Soil Survey, Territory of Hawaii, 1949.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon- the zone from the surface to 25 centimeters (10 inches) (Ap)
Argillic horizon- the zone from 25 to 147 centimeters (10 to 58 inches) (Bt1, Bt2, Bt3, Bt4)
FCC Classification: Cdhx-.
Edit Log: 5/19 MRK. Particle size family classification changed from fine to very-fine. Competing series updated and other minor edits. 3/17 MRK. Minor edits to Geographic Setting and format. 12/03 SN. Changed horizon pH using lab data; added pan evaporation data; updated Competing Series. 9/01 SN. Classification changed from Fine kaolinitic, isohyperthermic Ustic Palehumults.
ADDITIONAL DATA: Alaeloa NSSL sample S89HI-003-007 (formerly S89HI-007-007). Data for pedon S89HI-003-007 suggests particle size control section has greater than 60 percent clay. <50% kaolinite plus mica (46% est.) Needmore mineralogy (DTA) data. Bulk density data needed.
National Cooperative Soil Survey
U.S.A.