LOCATION AKAKA                   HI

Established Series
Rev. CWS/SN/HI/PGN/AMS
05/2012

AKAKA SERIES

The Akaka series consists of deep and very deep, moderately well drained soils that formed in material weathered from volcanic ash. Akaka soils are in ash fields on mid elevation, windward slopes of Mauna Kea volcano. Slopes range from 0 to 10 percent. The mean annual precipitation is about 5840 millimeters (230 inches) and the mean annual temperature is about 16 degrees C (60 degrees F).

TAXONOMIC CLASS: Hydrous, ferrihydritic, isothermic Acrudoxic Hydrudands

TYPICAL PEDON: Akaka highly organic silty clay loam, on an east facing 4 percent slope under a cover of low stature ohia forest with uluhe understory at an elevation of 530 meters (1740 feet). When described the soil was moist from 0 to 97 centimeters (0 to 38 inches) and saturated from 97 to 124 centimeters (38 to 49 inches). (Colors are for moist, crushed, soil unless otherwise noted).

A--0 to 18 centimeters (0 to 7 inches); dark brown (7.5YR 3/3) highly organic hydrous silty clay loam, dark brown (7.5YR 3/2) crushed, dry; moderate fine subangular blocky parting to moderate fine granular structure; soft, very friable, slightly sticky, slightly plastic; strongly smeary; common very fine and fine roots throughout; common very fine, fine, and medium dendritic tubular pores; 1 percent very fine, prominent, irregular, dark red (2.5YR 3/6) masses of oxidized iron with sharp boundaries between peds; 1 percent fine, prominent, cylindrical, weakly cemented, dark red (2.5YR 3/6) masses of oxidized iron with sharp boundaries lining pores; very strongly acid, pH 4.5 by pH meter 1:1 water; abrupt smooth boundary. (13 to 25 centimeters {5 to 10 inches} thick)

Bw1--18 to 26 centimeters (7 to 10 inches); dark brown (7.5YR 3/4) hydrous silty clay loam, dark brown (7.5YR 3/2) crushed, dry; weak fine subangular blocky structure; slightly hard, very friable, slightly sticky, slightly plastic; strongly smeary; few very fine roots throughout; common very fine, and few fine dendritic tubular pores; 2 percent very fine, prominent, irregular, dark red (2.5YR 3/6) masses of oxidized iron with sharp boundaries between peds and lining pores; very strongly acid, pH 4.7 by pH meter 1:1 water; abrupt smooth boundary. (8 to 51 centimeters {5 to 20 inches} thick)

Bs1--26 to 33 centimeters (10 to 13 inches); dark reddish brown (5YR 3/4) hydrous silty clay loam, dark reddish brown (5YR 3/2) crushed, dry; massive; slightly hard, very friable, slightly sticky, slightly plastic; strongly smeary; few very fine roots throughout; common very fine and few fine dendritic tubular pores; 12 percent fine and medium, distinct, yellowish red (5YR 4/6), moist ironstone nodules throughout; very strongly acid, pH 4.7 by pH meter 1:1 water; abrupt smooth boundary. (7 to 15 centimeters {3 to 6 inches} thick)

Bw2--33 to 43 centimeters (13 to 17 inches); very dark brown (7.5YR 2.5/3) hydrous silty clay loam, dark brown (7.5YR 3/2) crushed, dry; massive; slightly hard, very friable, slightly sticky, slightly plastic; strongly smeary; few very fine roots throughout; common very fine and few fine dendritic tubular pores; 2 percent fine, prominent, cylindrical, weakly cemented, dark red (2.5YR 3/6) moist masses of oxidized iron with sharp boundaries lining pores; 10 percent gravel sized weathered cinders; very strongly acid, pH 5.1 by pH meter 1:1 water; abrupt smooth boundary. (10 to 20 centimeters {4 to 8 inches} thick)

Bw3--43 to 58 centimeters (17 to 23 inches); dark reddish brown (5YR 3/3) hydrous silty clay loam, dark reddish brown (5YR 3/3) crushed, dry; moderate medium angular blocky structure; slightly hard, very friable, slightly sticky, slightly plastic; strongly smeary; few fine roots throughout; common very fine and few fine dendritic tubular pores; 10 percent gravel sized weathered cinders; strongly acid, pH 5.3 by pH meter 1:1 water; abrupt smooth boundary. (15 to 26 centimeters {6 to 11 inches} thick)

Bs2--58 to 66 centimeters (23 to 26 inches) dark reddish brown (5YR 3/4) hydrous silty clay loam, dark reddish brown (5YR 3/2) crushed, dry; massive; slightly hard, very friable, slightly sticky, slightly plastic; strongly smeary; few very fine roots throughout; common very fine and few fine dendritic tubular pores; 10 percent fine and medium, distinct, yellowish red (5YR 4/6), moist ironstone nodules throughout; strongly acid, pH 5.3 by pH meter 1:1 water; abrupt smooth boundary. (8 to 15 centimeters {3 to 6 inches} thick)

Bw4--66 to 125 centimeters (26 to 49 inches); dark brown (7.5YR 3/4) hydrous silty clay loam, dark brown (7.5YR 3/3) crushed, dry; weak course angular blocky structure; slightly hard, very friable, slightly sticky, slightly plastic; strongly smeary; few very fine roots in cracks; few very fine dendritic tubular pores; 5 percent fine, distinct, dendritic, very dark brown (10YR 2/2), moist masses of manganese concentrations with sharp boundaries lining pores and 15 percent very fine, distinct, irregular, very dark brown (10YR 2/2), moist masses of manganese concentrations with sharp boundaries between peds; strongly acid, pH 5.3 by pH meter 1:1 water; abrupt smooth boundary. (22 to 60 centimeters {9 to 24 inches} thick)

2R--125 centimeters (49 inches); highly weathered basalt.

TYPE LOCATION: Island of Hawaii; just past mile marker 8 on Hwy 19 (Mamalahoa Hwy) turn due west (mauka) on Indian Tree Road. Follow road 0.7 miles through locked gate and then proceed on pasture road 3.7 miles to 19 degrees 47 minutes 30.1 seconds North latitude, 155 degrees 8minutes 54.2 seconds West longitude. Park and walk 0.1 miles due west on forest trail. Turn due north and follow trail downhill to Kaieie stream. Cross stream to open bog area. Type location is just north of the bog; Akaka Falls Quandrangle 19 degrees 47 minutes 48.2 seconds North latitude and 155 degrees 09 minutes 19.4 seconds West longitude, (Old Hawaiian Datum, 6 ft., measured by GPSmap 76CSx).

RANGE IN CHARACTERISTICS:
Depth to bedrock: 105 to over 150 centimeters (41 to over 60 inches).
Soil moisture: The soil is typically moist in the surface and can be saturated beginning at a depth from 25 to 75 centimeters (10 to 30 inches).
Rock fragments: 5 to 15 percent gravel.
Soil temperature: 16 to 20 degrees C (60 to 68 degrees F).

A horizon
Hue: 5YR or 10YR.
Value: 2 to 3 moist.
Chroma: 2 to 4 moist.
Texture: highly organic hydrous silty clay loam or hydrous silty clay loam.
Redoximorphic features: 0 to 2 percent masses of oxidized iron 2.5YR 3/4 or 2.5YR 3/6.

Bw horizons
Hue: 5YR or 10YR.
Value: 2.5 to 3 moist.
Chroma: 1 to 6 moist.
Redoximorphic features: 0 to 15 percent masses or nodules of oxidized iron 2.5YR 3/4, 2.5YR 3/6, or manganese concentrations 10YR 2/2, between peds or in root channels or pores.

Bs horizons
Hue: 2.5YR or 5YR.
Chroma: 3 or 4 moist.
Redoximorphic features: 0 to 15 percent masses of oxidized iron or ironstone nodules 2.5YR 3/4, 2.5YR 3/6, or 5YR 4/6 between peds or in root channels or pores.
Moist consistency: Very friable to firm.

COMPETING SERIES: These are the Kaiwiki, Honokaa, Honomanu, Kehena, Maile, and Ohia soils. Kaiwiki soils are well drained. Honokaa and Maile soils are well drained and have a udic moisture regime. Honomanu and Kahena soils are moderately deep to bedrock. Ohia soils are well drained and found on younger Mauna Loa lava flows.

GEOGRAPHIC SETTING: Akaka soils are in ash fields on mid-elevation windward slopes of Mauna Kea volcano at elevations of 335 to 1615 meters (1100 to 5300 feet). Soils are formed from weathered volcanic ash underlain by 100 to 300 thousand year old pahoehoe and `a`a lava flows. They are found at footslopes and toeslopes in the hillslope profile. Slopes are 0 to 10 percent. Mean annual precipitation is 5000 to over 6000 millimeters (200 to over 240 inches). The mean annual temperature is 15 to 21 degrees C (59 to 69 F). The mean summer soil temperature and the mean winter soil temperature differ by less than 6 degrees C (11 degrees F)

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Kaiwiki and Onomea soils. The Kaiwiki soils are typically found in the summit, shoulder or backslope position and are well drained. Onomea soils are found at toeslopes or in depressions and are very poorly drained.

DRAINAGE AND PERMEABILITY: Moderately well drained. Runoff is low to high. Permeability is moderately slow in the soil and very slow in the underlying bedrock.

USE AND VEGETATION: These soils are used for forestland, livestock grazing, wildlife habitat, and orchard crops. Vegetation is ohia lehua (Metrosideros polymorpha), hapuu or treefern (Cibotium chammisoi), uluhe fern or false staghorn fern (Gleichenia linearis), or strawberry guava (Psidium catleianum).

DISTRIBUTION AND EXTENT: The soils are moderately extensive with a total of about 25,000 acres. MLRA is 159A.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California

SERIES ESTABLISHED: Soil Survey, Territory of Hawaii, 1949.

REMARKS:
Diagnostic horizons and features recognized in this pedon include: Perudic Moisture Regime.
Isothermic Temperature Regime.
Andic soil properties- 0 to 125 centimeters (0 to 50 inches) (A, Bw, Bs, Bw2, Bw3, Bs2 and Bw4 horizons).
Umbric epipedon- 0 to 18 centimeters (0 to 7 inches) (A horizon).
Cambic horizon- 18 to 125 centimeters (7 to 49 inches) (Bw, Bs, Bw2, Bw3, Bs2 and Bw4 horizons).
Lithic contact- 125 centimeters (49 inches) (2R horizon).

ADDITIONAL DATA:
NSSL pedons sampled as Akaka: 61HI-001-002 (formerly S61Ha-1-2), 87HI-001-005, and 07HI-001-002, S09HI001003 USER SITE ID: 08HI602319
Fertility Capability Classification: Caekx.

Edit Log:
12/03 SN. Changed rainfall RV from 225 inches to 200, changed horizon designations, added FCC, plus minor edits.
8/00 SN. Classification changed from Thixotropic, isomesic Typic Hydrandepts due to changes in Taxonomy.
02/09 PGN. Revision to OSD to better reflect drainage and mapping in update of the Island of Hawaii soil survey.
Type location moved from lat. 19 degrees 44 minutes 52 seconds N. and long. 155 degrees 10 minutes 25 seconds W. (Old Hawaiian Datum) to current.

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National Cooperative Soil Survey
U.S.A.