LOCATION HULUA HIEstablished Series
TAXONOMIC CLASS: Hydrous, amorphic, isothermic Placic Petraquepts
TYPICAL PEDON: Hulua gravelly silty clay - brush and scrubby ohia. (Colors are for moist soils unless otherwise noted. All textures are "apparent field textures".)
01--1 inch to 0; uluhe fern litter. Undecomposed laye of stems and leaves of the uluhe fern.
A1g--0 to 10 inches; black (5Y 2/1) gravelly silty clay, dark gray (2.5Y 4/1) dry; massive; very hard, firm, slightly sticky, plastic, and weakly smeary; many roots; irregular shaped ironstone pebbles 0.3 to 0.5 inches across; very many small glistening particles; strongly acid (pH 5.2); clear wavy boundary. (7 to 12 inches thick)
A2--10 to 16 inches; dark grayish brown (2.5Y 4/2) silty clay, reddish yellow (7.5YR 6/6) dry; coatings of brown (10YR 4/3) mottles of wghite (10YR 8/2) and strong brown (7.5YR 5/8) dry; massive; hard, firm, sticky, plastic, and weakly smeary; common roots; few very fine pores; strongly acid (pH 5.2); abrupt smooth boundary. (3 to 8 inches thick)
B2ir--16 to 18 inches; very dark brown (7.5YR 2/2 and 2/4) and brown (7.5YR 4/4) strongly cemented ironstone sheet; some fine pores contain a whitish soft material; ironstone sheet is laminated and has a troweled upper surface; clear wavy boundary. (1/2 to 3 inches thick)
C1--18 to 30 inches; yellowish red (5YR 5/6) clay loam, reddish yellow (7.5YR 6/6) dry; appearance of original rock structure but with pores coated with material of strong brown (7.5YR 5/6), red (2.5YR 4/8), and yellowish red (5YR 5/8) colors; fracture faces have coatings of reddish black (10R 2/1), dark red (10R 3/6), and black (N 2/) moist; hard, firm, sticky, plastic and smeary; many fine pores; this layer consists of hard and soft matrial; hard material can be broken down, when moist, with difficulty; very strongly acid (pH 4.8); gradual smooth boundary. (11 to 14 inches thick)
C2--30 to 60 inches; very dusky red (2.5YR 2/2) clay loam, weak red (2.5YR 4/2) dry; many fine mottles of reddish yellow (7.5YR 7/6), dark red (7.5YR 3/6), and yellowish red (5YR 5/6), red (2.5YR 5/6) Aand reddish yellow (7.5YR 7/6) dry; hard, firm, sticky and plastic; common medium and fine pores; appearance of the original rock structure but the pores are all filled with illuvial material; very strongly acid (pH 4.5).
TYPE LOCATION: Island of Kauai, Kauai County, Hawaii; 21 degrees 58 feet 16.6 inches N. latitude and 159 degrees 30 feet 21.3 inches W. longitude.
RANGE IN CHARACTERISTICS: Depth to the ironstone sheet is 10 to 20 inches. Thickness of the ironstone sheet ranges from a thin (1/32 inches) cap to 2 or 3 inches. The mean annual soil temperature is about 66 degrees F.. The A horizon has moist hue of 2.5Y or 5Y, and moist value of 2 or 3. The A2 horizon shows rapid oxidationwhen exposed to the air, changing from a hue of 2.5Y to 7.5YR and a chroma of 2 to 6. The material below the ironstone sheet has hue of 10R through 7.5YR, value of 2 through 5, and chroma of 2 through 8.
COMPETING SERIES: These are the Amalu, Koolau, Kunuweia, and Olokui series. Amalu soils have a histic epipedon and have a mean annual soil temperature os less than 59 degrees F. Koolau soils lack a spodic horizon. Kunuweia soils are well drained, lack an albic horizon, and have no spodic horizon. Olokui soils have mean annua soil temperature of less than 59 degrees F. and have moderate structure in the albic horizon.
GEOGRAPHIC SETTING: The Hulua soils are on uplands. Slope is 3 to 70 percent, dominantly 20 to 35 percent. Elevation ranges from 400 to 2,400 feet. The soils formed in residuum from basic igneous rock. The annual rainfall is 100 to 200 inches. The average January temperature is about 64 degrees F.; the average July temperature is about 68 degrees F.; and the mean annual temperature is about 66 degrees F.
GEOGRAOHICALLY ASSOCIATED SOILS: These are the Halii, Koolau, and Pooku soils. Koolau and Pooku soils lack a continuous cemented ironstone sheet.
DRAINAGE AND PERMEABILITY: Poorly drained; rapid runoff; moderately rapid permeability, except for the ironstone sheet which is nearly impermeable.
USE AND VEGETATION: Used for watershed. Vegetation is mainly false staghorn fern, scrub ohia lehua, ukiuki, club moss, hilograss, and associated plants.
DISTRIBUTION AND EXTENT: Island of Kauai, Hawaii. This series is inextensive, with a total of approximately 5,300 acres.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Kauai County, Hawaii, 1978.