LOCATION PAKINI                  HI

Established Series
Rev. MRK-RTG
06/2012

PAKINI SERIES

The Pakini series consists of deep and very deep, well drained soils formed in basic volcanic ash. Slopes are dominantly 2 to 10 percent and range to 70 percent. The mean annual rainfall is about 640 millimeters (25 inches), and the mean annual temperature is about 23 degrees C. (74 degrees F.)

TAXONOMIC CLASS: Medial, amorphic, isohyperthermic Typic Haplotorrands

TYPICAL PEDON: Pakini medial very fine sandy loam, on a south facing, linear, 3 percent slope under pasture at an elevation of 122 meters (400 feet). (Colors are for dry soil unless otherwise noted. All textures are "apparent field textures". pH measured with electrode in 1:1 water. When described on April 8, 1965 the soil was dry throughout.)

Ap--0 to 8 centimeters (0 to 3 inches); dark grayish brown (10YR 4/2) medial very fine sandy loam, very dark brown (10YR 2/2) moist; weak medium platy structure; slightly hard, very friable, nonsticky and nonplastic; many fine roots; 5 percent gravel; neutral (pH 7.1); abrupt smooth boundary. (5 to 10 centimeters {2 to 4 inches) thick}

A1--8 to 20 centimeters (3 to 8 inches); dark yellowish brown (10YR 4/4) medial very fine sandy loam, dark brown (7.5YR 3/3) moist; weak medium and coarse prismatic structure; slightly hard, friable, nonsticky and nonplastic; many fine roots; 5 percent gravel; neutral (pH 7.1); clear wavy boundary. (10 to 13 centimeters {4 to 5 inches} thick)

A2--20 to 41 centimeters (8 to 16 inches); yellowish brown (10YR 5/4) medial very fine sandy loam, brown (7.5YR 4/4) moist; weak coarse prismatic structure; slightly hard, friable, nonsticky and nonplastic; common fine roots; 5 percent gravel; neutral (pH 7.2); clear wavy boundary. (18 to 25 centimeters {7 to 10 inches} thick)

Bw1--41 to 74 centimeters (16 to 29 inches); strong brown (7.5YR 5/6) medial loam, brown (7.5YR 4/4) moist; weak coarse prismatic structure; slightly hard, friable, slightly sticky and slightly plastic; few fine roots; common olivine sand; slightly alkaline (pH 7.6); gradual wavy boundary. (25 to 46 centimeters {10 to 18 inches} thick)

Bw2--74 to 114 centimeters (29 to 45 inches); yellowish brown (10YR 5/6) medial loam, brown (7.5YR 5/4) moist; weak coarse prismatic structure; slightly hard, friable, slightly sticky and slightly plastic; few fine roots; 2 percent gravel; few distinct, white, calcium carbonate coatings on vertical prism faces and in pores; slightly alkaline (pH 7.7); gradual wavy boundary. (31 to 51 centimeters {12 to 20 inches} thick)

Ck--114 to 152 centimeters (45 to 60 inches); yellowish brown (10YR 5/6) medial very fine sandy loam, brown (7.5YR 5/4) moist; massive; slightly hard, friable, nonsticky and nonplastic; slightly effervescent, few pockets are violently effervescent; calcium carbonate increases with depth; slightly alkaline (pH 7.7).

TYPE LOCATION: Island of Hawaii, Hawaii County, Hawaii; about 274 meters (900 feet) east of the old tracking station near South Point, Ka`u. Ka Lae Quadrangle; lat. 18 degrees 56 minutes 30 seconds N. and long. 155 degrees 40 minutes and 57 seconds W. (Old Hawaiian Datum).

RANGE IN CHARACTERISTICS:
Depth to bedrock: 102 to 152 centimeters (40 to 60 inches) or more.
Depth to Ck horizon: 76 to 140 centimeters(30 to 55 inches).
Mean annual soil temperature: 22 to 24 degrees C. (72 to 76 degrees F.)
Rock fragments: 0 to 15 percent by volume of the pedon and range in size from gravel to cobbles.
Sand: Thin layers high in olivine are common at depths of 25 to 125 centimeters (10 to 50 inches).

A horizon
Hue: 7.5YR or 10YR.
Value: 2 to 4 moist and 4 or 5 dry.
Chroma: 2 to 4 moist or dry.
Structure: Weak platy or weak prismatic.
Soil reaction: Neutral or slightly alkaline.

Bw horizon
Value: 3 to 5 moist or dry.
Chroma: 4 to 6 moist or dry.

Ck horizon
Effervescence: Slightly to violently effervescent.

COMPETING SERIES: These are the Oanapuka and Puako series. Oanapuka soils have a mollic epipedon and do not have olivine sand. Puako soils formed in alluvium and do not have carbonates in the subsoil.

GEOGRAPHIC SETTING: Pakini soils are on south and east slopes on the coastal uplands low elevation, windward slopes of Mauna Loa and Kilauea volcanoes at elevations from sea level to 305 meters (0 to 1000 feet). The soils are on all hillslope positions of nearly level to very steep lava flows that are greater than 10,000 years old. Slope gradients are dominantly 2 to 10 percent and range to 70 percent. The soils formed in basic volcanic ash and contain much olivine sand. The mean annual rainfall ranges from 380 to 760 millimeters (15 to 30 inches). The mean annual pan evaporation ranges from 2030 to 2290 millimeters (80 to 90 inches). The mean annual temperature ranges from 22 to 24 degrees C. (72 to 76 degrees F.) The mean summer and the mean winter soil temperatures differ by less than 6 degrees C. (11 degrees F.)

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Kaalualu and Kanohina series. Kaalualu soils are medial-skeletal and are noncalcareous throughout. Kanohina soils are shallow over pahoehoe lava.

DRAINAGE AND PERMEABILITY: Well drained. Runoff is low to medium on gentle slopes and medium to high on steeper slopes. Permeability is moderately rapid.

USE AND VEGETATION: These soils are used for grazing and wildlife habitat. Vegetation is sandbur (Cenchrus echinatus), cocklebur (Xanthium saccharatum), lantana (Lantana camara), bermudagrass (Cynodon dactylon), and piligrass (Heteropogon contortus).

DISTRIBUTION AND EXTENT: Ka`u District, Island Of Hawaii; MLRA 157. The series is of small extent.

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 are:
Ochric epipedon - from 0 to 20 centimeters (0 to 8 inches) (Ap, A1 and A2 horizons).
Cambic horizon - from 20 to 114 centimeters (8 to 45 inches).
Andic soil properties - from 0 to 152 centimeters (0 to 60 inches).
Soil moisture - dry in all parts for more than half of the cumulative days per year and are moist in some or all parts for less than 90 consecutive days (Aridic/Torric moisture regime).

ADDITIONAL DATA: NASIS User Pedon ID 00HI602002. Type location, SSIR-29, p.53, NSSL sample S65HI-001-009. Erodibility of Selected Hawaii Soils by Rainfall Simulation, ARS W-35, 1976.

Edit Log: 12/03 MRK. Added "medial" modifiers to textures.
10/99 MRK. Classification revised due to changes in Soil Taxonomy. Old classification: Medial, isohyperthermic Entic Eutrandepts. Competing series updated. 4/09 MRK. Minor edits made.

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National Cooperative Soil Survey
U.S.A.