LOCATION PAAUHAU HI
Established Series
Rev. CWS-SN-MRK
06/2012
PAAUHAU SERIES
The Paauhau series consists of deep, well drained soils that formed in basic volcanic ash over pahoehoe lava. Paauhau soils are on ash fields and have slopes of 0 to 70 percent. The mean annual rainfall is about 1,778 millimeters (70 inches), and the mean annual temperature is about 23 degrees C. (73 degrees F.)
TAXONOMIC CLASS: Medial over hydrous, amorphic, isohyperthermic Dystric Haplustands
TYPICAL PEDON: Paauhau medial silt clay loam, on a north facing, 10 percent slope under grass pasture at an elevation of 129 meters (425 feet). (Colors are for moist soil unless otherwise noted. All textures are "apparent field textures.") ph measured with electrode in 1:1 soil to water. When described on July 8, 2009 the soil was slightly moist in the surface and dry below.)
A--0 to 13 centimeters (0 to 5 inches); very dark brown (10YR 2/2) medial silty clay loam, dark yellowish brown (10YR 3/4) dry; moderate medium granular structure; firm, hard, moderately sticky and moderately plastic; moderately smeary, many fine roots; many fine interstitial and few fine tubular pores; 5 percent gravel; moderately acid (pH 5.7); clear smooth boundary. (10 to 15 centimeters {4 to 6 inches} thick)
AB--13 to 25 centimeters (5 to 10 inches); very dark brown (10YR 2/2) medial silty clay loam, dark yellowish brown (10YR 3/4) dry; weak fine granular structure; friable, slightly hard, moderately sticky, and moderately plastic; moderately smeary; many fine roots; common fine interstitial and tubular pores; 5 percent gravel; moderately acid (pH 5.6); clear smooth boundary. (10 to 15 centimeters {4 to 6 inches} thick)
Bw1--25 to 43 centimeters (10 to 17 inches); dark brown (10YR 3/3) hydrous silty clay loam, dark yellowish brown (10YR 3/6) dry; moderate medium subangular blocky structure; friable, slightly hard, very sticky, and moderately plastic; moderately smeary; many fine roots; common fine interstitial and tubular pores; 5 percent gravel; moderately acid (pH 5.6); clear smooth boundary. (15 to 20 centimeters {6 to 8 inches} thick)
Bw2--43 to 61 centimeters (17 to 24 inches); dark brown (10YR 3/3) hydrous silty clay loam, dark yellowish brown (10YR 3/4) dry; weak medium subangular blocky structure; friable, slightly hard, very sticky, and very plastic; moderately smeary; few fine roots; few fine tubular pores; 10 percent gravel and 2 percent cobbles; moderately acid (pH 6.0); diffuse wavy boundary. (15 to 20 centimeters {6 to 8 inches} thick)
Bw3--61 to 76 centimeters (24 to 30 inches); dark yellowish brown (10YR 3/4) hydrous silty clay loam, dark yellowish brown (10YR 3/6) dry; weak medium subangular blocky structure; friable, slightly hard, slightly sticky, and slightly plastic; moderately smeary; common fine roots; common very fine interstitial and few very fine tubular pores; 10 percent gravels; slightly acid (pH 6.4); clear wavy boundary. (15 to 20 centimeters {6 to 8 inches} thick)
Bw4--76 to 104 centimeters (30 to 41 inches); dark brown (7.5YR 3/4) hydrous silty clay loam, brown (7.5YR 4/4) dry; weak fine subangular blocky structure; very firm, hard, slightly sticky, and slightly plastic; moderately smeary; common fine roots; common very fine tubular and common medium irregular pores; 5 percent cobbles; slightly acid (pH 6.4); clear smooth boundary. (25 to 35 centimeters {10 to 14 inches} thick)
2Cr--104 to 117 centimeters (41 to 46 inches); black (7.5YR 2.5/1) very gravelly silt loam, dark brown (7.5YR 3/2) dry; massive parting to weak medium subangular blocky structure; very firm, hard, nonsticky, and nonplastic; nonsmeary; few very fine and fine roots; common fine tubular pores; 40 percent gravel and 2 percent cobbles; neutral (pH 6.6); abrupt wavy boundary. (10 to 15 centimeters {4 to 6 inches} thick)
2R--117 centimeters (46 inches); hard bedrock.
TYPE LOCATION: Island of Hawaii, Hawaii County, Hawaii; from Honokaa Town, at the junction of Plumeria St. and Highway 240, drive about 2.9 miles northwest on Highway 240. Turn right and pass through gate entrance, drive about 0.7 miles torward the ocean. Turn right (east) and drive about 0.5 miles. Turn left into field between Ironwood windbreaks and turn left again. Pedon is located about 6 meters (20 feet) east of highway at an elevation of 129 meters (425 feet). Kukuihaele Quadrangle; latitude 20 degrees 06 minutes 34.3 seconds north and longitude 155 degrees 30 minutes 13.6 seconds west (old Hawaiian datum.)
RANGE IN CHARACTERISTICS:
Depth to bedrock: 102 to greater than 152 centimeters (40 to 60 inches). Mean annual soil temperature: 22 to 24 degrees C (72 to 75 degrees F.)
The A horizon Hue: 5YR to 10YR. Value: 2 or 3 Chroma: 2 or 3 Texture: Medial or hydrous, silty clay loam or silt loam. Structure: Weak to moderate, very fine to medium, granular or subangular blocky.
Smeariness: Weakly to moderately smeary
The Bw horizon Hue: 5YR to 10YR. Value: 2 to 4 Chroma: 2 to 4 Texture: Medial or hydrous, silty clay loam or silt loam. Structure: Weak to moderate, very fine to medium, subangular blocky.
Smeariness: Weakly to moderately smeary
The Bw horizon is more smeary as elevation and rainfall increase.
The Bw horizon dehydrates irreversibly into dark brown or black, very hard sand- and silt-size aggregates.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Paauhau soils are on northwest low elevation, windward slopes of Muana Kea shield volcano at elevations from 0 to 335 meters (0 to 1,100 feet). These soils are on all hillslope positions of gently sloping to steep ash fields and gulches on lava flows. Slope gradients range from 0 to 70 percent. The soils formed in basic volcanic ash over basaltic lava. The mean annual rainfall ranges from 1,524 to 2,032 millimeters (60 to 80 inches), with most of the rainfall occurring from October through April. The mean annual temperature ranges from 21 to 23 degrees C. (70 to 74 degrees 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
Kukaiau and
Ookala soils. Kukaiau soils have a udic soil moisture regime and are isothermic. Ookala soils have a udic soil moisture regime.
DRAINAGE AND PERMEABILITY: Well drained; low to high runoff; moderate to moderately rapid permeability.
USE AND VEGETATION: These soils are used for grazing and vegetable crops. They were used extensively for irrigated sugarcane (Saccharum spp.) in the past. Natural vegetation is bermudagrass (Cynodon dactylon), hilograss (paspalum congugatum), and kaimi clover (Desmodium incanum).
DISTRIBUTION AND EXTENT: Hamakua District, Island of Hawaii. It is inextensive with about 7,000 acres. MLRA 158.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.
SERIES ESTABLISHED: Soil Survey, Territory of Hawaii, 1949.
REMARKS: Diagnostic horizons and feature in this pedon are:
Umbric epipedon - from the surface to 25 centimeters (0 to 10 inches) (A and AB horizons).
Andic soil properties - from 0 to 104 centimeters (0 to 41 inches) (A, AB, and Bw horizons).
Cambic Horizon - from 25 to 104 centimeters (10 to 41 inches) (Bw horizons).
Paralithic contact - from 104 to 117 centimeters (41 to 46 inches) (2C horizon).
Lithic contact - at 117 centimeters (46 inches) (2R horizon).
ADDITIONAL DATA: NASIS User Pedon ID 09HI603002. NSSL samples S87-HI-001-004 and S05-HI-001-002.
Edit Log: 5/01 SN. Initial entry in OSD file. Classification changed from Thixotropic, isohyperthmic Hydric Dystrandepts due to changes in Taxonomy. 11/09 MRK. Soil moisture regime changed to ustic and classification changed. Range in characteristics, competing series and geographic setting updated. Other minor edits.
National Cooperative Soil Survey
U.S.A.