LOCATION WAIKAPU HI

Established Series
Rev. RCH/JVP/MRK
03/2017

WAIKAPU SERIES

The Waikapu series consists of deep, well drained soils that formed in material weathered from old alluvium. Waikapu soils are on alluvial fans and have slopes of 0 to 15 percent. Mean annual rainfall is about 508 millimeters (20 inches) and mean annual temperature is about 23 degrees C. (73 degrees F.)

TAXONOMIC CLASS: Fine, kaolinitic, isohyperthermic Typic Haplotorrox

TYPICAL PEDON: Waikapu silty clay loam - cultivated. (Colors are for moist soil unless otherwise noted. All textures are "apparent field textures.")

Ap1--0 to 10 centimeters (0 to 4 inches); dark reddish brown (5YR 3/2) silty clay loam, dark reddish brown (5YR 3/3) dry; weak very fine granular structure; soft, very friable, sticky and plastic; few roots; many interstitial pores; common very fine vertical tubular pores; many fine black concretions; violent effervescence with hydrogen peroxide; strongly acid (pH 5.1); clear wavy boundary. (8 to 13 centimeters {3 to 5 inches} thick)

Ap2--10 to 31 centimeters (4 to 12 inches); dark reddish brown (5YR 3/2) light silty clay loam, reddish brown (5YR 4/4) dry; weak medium and fine subangular blocky structure, some pockets of weak very fine granular structure; soft, friable, sticky and plastic; many roots; many very fine and few fine tubular pores; common fine black concretions; violent effervescence with hydrogen peroxide; slightly acid (pH 6.1); gradual wavy boundary. (18 to 25 centimeters {7 to 10 inches} thick)

Bw--31 to 61 centimeters (12 to 24 inches); dark reddish brown (2.5YR 3/4) silty clay loam, reddish brown (2.5YR 4/4) dry; strong fine and very fine angular and subangular blocky structure; slightly hard, friable, sticky and plastic; firm in place; few roots; many very fine and fine and few medium tubular pores; patchy glaze on faces of peds; common fine black concretions; violent effervescence with hydrogen peroxide; common fine hard earthy lumps which break down slowly upon rubbing; neutral (pH 7.0); gradual wavy boundary. (25 to 36 centimeters (10 to 14 inches thick)

Bo1--61 to 86 centimeters (24 to 34 inches); dark reddish brown (2.5YR 3/4) moist and dry silty clay loam; moderate medium subangular blocky structure parting to strong fine and very fine angular blocky; soft, friable, sticky and plastic; moderately firm in place; many very fine and fine and few medium tubular pores; weakly expressed patchy pressure faces; many black concretions, commonly up to 2 mm. in diameter; violent effervescence with hydrogen peroxide; neutral (pH 7.2); gradual wavy boundary. (20 to 31 centimeters (8 to 12 inches thick)

Bo2--86 to 112 centimeters (34 to 44 inches); reddish brown (5YR 5/3) silty clay loam, dark reddish brown (5YR 3/4) dry; weak medium and fine subangular blocky structure; few weakly grooved slickensides; soft, very friable sticky and plastic; many very fine and fine and common medium tubular pores; many black concretions; violent effervescence with hydrogen peroxide; neutral (pH 7.2); clear wavy boundary. (20 to 31 centimeters (8 to 12 inches thick)

Bss--112 to 152 centimeters (44 to 60 inches); pale red (2.5YR 6/2) silty clay loam, dark reddish brown (2.5YR 3/4) dry; weak medium subangular blocky structure parting to moderate fine and very fine subangular blocky; few slickensides; soft, friable, sticky and plastic; many very fine and fine and common medium tubular pores; patchy glaze on some peds; common fine hard earthy lumps that are broken down by persistent rubbing; few fine black concretions; slight effervescence with hydrogen peroxide; neutral (pH 7.2).

TYPE LOCATION: Island of Lanai, Maui County, Hawaii; Island of Lanai, Maui County, Hawaii; Latitude 20 degrees 47 minutes 13 seconds N. and longitude 156 degrees 56 minutes 12 seconds W. Old Hawaiian datum; Dole Company plantation, 31 meters (100 feet) north of the south end of Block C-8 in field 5514.

RANGE IN CHARACTERISTICS: The mean annual soil temperature (MAST) is 23 to 26 degrees C. (73 to 79 degrees F.). The difference between the mean summer and winter temperature is less than 6 degrees C. Black concretions are throughout the solum and range in size from fine specks to 3 millimeters. Effervescence with hydrogen peroxide is strong to violent in the A and B horizons. Mean annual soil temperature is about 73 degrees F. The soil is dry below a depth of 25 centimeters (10 inches) for more than 6 months in most years. The solum has hue of 5YR or 2.5YR.

The A horizon
value and chroma of 2 or 3 moist and value of 3 or 4 dry.

The B horizon
value of 2 or 3 moist, 3 or 4 dry
chroma of 3 through 6 moist.
Slickensides are few to common in the lower part of the B horizon.

COMPETING SERIES: There are no competing series.

GEOGRAPHIC SETTING: The Waikapu soils are on gently to moderately sloping alluvial fans at elevations of 12 to 447 meter (39 to 1,467 feet). The soils formed in old alluvium from material washed from basic igneous rocks. Average annual rainfall is Average annual rainfall is 490 to 822 millimeters (19 to 32 inches).. Average January temperature is about 22 degrees C. (71 degrees F.), average July temperature is about 25 degrees C. (77 degrees F.), and the mean annual temperature is about 23 degrees C. (73 degrees F.)

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Holomua, Molokai and Uwala soils. Holomua soils lack pressure faces and slickensides. Molokai soils have prismatic structure in the B horizon and lack slickensides. Uwala soils are medium acid in the B horizon.

DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderate permeability.

USE AND VEGETATION: Used for growing pineapple, pasture and wildlife. Wild vegetation is lantana (Lantana camara), bermudagrass (Cynodon dactylon), illima (Sida fallax), and feather fingergrass (Chloris virgata).

DISTRIBUTION AND EXTENT: This soil is on the islands of Molokai and Lanai, Maui County, Hawaii. The series is not extensive.

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Davis, California

SERIES ESTABLISHED: Island of Maui, Maui County, Hawaii, 1949.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Umbric epipedon - the zone from a depth of 0 to 30 cm (Ap1 and Ap2 horizons)
Oxic horizon- the zone from a depth of 30 to 86 cm (Bo and Boss horizons)
Slickensides - the zone from a depth of 86 to 152 cm (Boss and Bss horizons)
Iron manganese concentrations- the zone from a depth of 0 to 152 cm.
OSED scanned by SSQA. Last revised by state on 3/01 until 3/17

National Cooperative Soil Survey
U.S.A.