The Hoesu series are members of the medial, ferrihydritic, thermic family of Typic Hapludands [Umbric Aluandic Andosols (Dystric Siltic) classified by WRB]. These soils have very dark brown gravelly silt loam Ap horizons, dark brown gravelly silt loam AB horizons, dark brown gravelly silt loam Bw1 horizons, dark brown gravelly silt loam Bw2 horizons, and brown gravelly silt loam BC horizons. They occur on lava plains and are derived from pyroclastic materials.

Typifying Pedon: Hoesu gravelly silt loam-wild grass (Colors are for moist soil).

  Slope: 7-15%

  Elevation: 250 m above m.s.l.

  Soil moisture regime: Udic

  Soil temperature regime: Thermic

  Parent material: Pyroclastic materials

  Diagnostic features: An umbric epipedon from a depth of 0 to 42 cm, a cambic horizon from a depth of 42 to 101 cm, and an andic soil properties from a depth of 0 to 160 cm (An umbric horizon from a depth of 0 to 42 cm, a cambic horizon from a depth of 42 to 101 cm, and an andic properties from a depth of 0 to 160 cm by WRB).

  Described by: Song, K. C., D. C. Noh, and B. K. Hyun,  24 Feb., 2012.

Morphological properties of typifying pedon.

A - 0 to 13 cm. Very dark brown (10YR 2/2) gravelly silt loam; moderate fine to medium granular structure; friable, slightly sticky and slightly plastic; many fine to medium roots; few medium pores; 10% gravels; gradual wavy boundary.

AB - 13 to 42 cm. Dark brown (7.5YR 3/2) gravelly silt loam; weak coarse subangular blocky structure; friable, slightly sticky and slightly plastic; common fine to medium roots; few medium pores; 10% gravels; gradual wavy boundary.

Bw1 - 42 to 72 cm. Dark brown (7.5YR 3/3) gravelly silt loam; moderate medium subangular blocky structure; friable, slightly sticky and slightly plastic; thin patch clay cutans; few fine to medium roots; few medium pores; 15% gravels; clear wavy boundary.

Bw2 - 72 to 101 cm. Dark brown (7.5YR 3/3) gravelly silt loam; moderate medium to coarse subangular blocky structure; friable, sticky and plastic; thin continuous clay cutans; few fine to medium roots; few medium pores; 25% gravels; abrupt wavy boundary.

BC - 101 to 160 cm. Brown (7.5YR 4/3) silty clay loam; weak coarse platy structure; slightly firm, sticky and plastic; thin continuous clay cutans; few fine roots; few medium pores; 5% gravels.

  The typifying pedon has an umbric epipedon from a depth of 0 to 42 cm and a cambic horizon from a depth of 42 to 101 cm. That contains oxalate extractable (Al + 1/2Fe) content equal to 2.0 or more, phosphate retention of 85% or more, and bulk density of 0.90 Mg/m³ or less from a depth of 0 to 160 cm. Therefore it has an andic soil properties at that depth. It can be classified as Andisol. It has an udic soil moisture regime, and can be classified as Udand. Also it meets the requirements of Typic Hapludand.

  It has a fine-earth fraction that has a water content at 1,500 kPa tension of 12% or more on air-dried samples, and has less than 35% (by volume) rock fragments. Thus its substitute for particle-size class is medial. It has a sum of 8 times the Si (percent by weight extracted by ammonium oxalate from the fine-earth fraction) plus 2 times the Fe (percent by weight extracted by ammonium oxalate from the fine-earth fraction) of 5 or more, and 8 times the Si is more than 2 times the Fe. it has ferrihydritic mineralogy class and mesic soil temperature class. Therefore it can be classified as medial, ferrihydritic, thermic family of Typic Hapland.

Type Location: About 300 meters north-east of the Hoesu Cemetery, Hoesu Dong, Seogwipo city, Jeju Do (126° 27' 10.0'', 33° 16' 29.2'').

Range in Characteristics: These soils have umbric epipedons, cambic horizons, and andic soil properties. Solum thickness ranges from 100 to 150 cm and depth to hard rock is more than 2 meters. Reaction is medium to slightly acid. Base saturation is less than 50 percent. A horizons are dark brown or very dark brown gravelly silt loam. B horizons are dark brown, dark grayish brown, or dark yellowish brown gravelly silt loam or silty clay loam.

Competing Series and Their Differentiae: These are the Udo, Songag, and Ora soils. The Udo soils lack coarse fragments throughout the profiles. The Songag soils occur on cinder cones. The Ora soils are belonged to Andic Humudepts.

Setting: The Hoesu soils are developed on lava plains and are derived from pyroclstic materials.  Slope ranges from 2 to 30 percent and 2 to 15 percent slopes are predominant.

Principal Associated Soils: The Andeog, Jungmun, and Jeongbang, and Ara soils are associated at similar physiographic positions.

Drainage and Permeability: Well drained. Permeability is moderately rapid. Runoff is medium.

Use and Vegetation: Most of these soils are used for upland crops such as barley, sweet potato, oil vegetables, potato, and the remaining areas are grass land growing grass and shrub.

Distribution and Extent: The Hoesu soils are of moderate extent and are distributed on lava plains in Jeju Do.

Series Established: Seogwipo city, Jeju Do, 2012..

Laboratory data sheets of typifying pedon.

Depth (cm)	Horizon	( --- Total ---)			(-- Clay --)		(-- Silt --)		(------- Sand -------)
		Clay	Silt	Sand	Fine	Coarse	Fine	Coarse	VF	F	M	C	VC
		LT	.002	.05	LT	LT	.002	.02	.05	.10	.25	.5	1
		.002	- .05	- 2	.0002	.002	- .02	- .05	- .10	- .25	- .50	- 1	- 2
		- - - - - - - - - - - Pct of ˂ 2mm (3A1) - - - - - - - - - - -
0-13	A	25.6	65.5	8.9			40.4	25.1	2.8	3.3	1.7	0.9	0.3
13-42	BA	28.1	64.4	7.5			36.8	27.6	2.6	2.9	1.2	0.6	0.2
42-72	Bw1	27.8	64.5	7.7			35.2	29.3	2.8	2.8	1.3	0.6	0.2
72-101	Bw2	27.5	65.4	7.1			34.7	30.7	2.5	2.4	1.2	0.7	0.3
101-160	BC	38.9	58.1	3.0			26.6	31.5	1.2	1.2	0.4	0.2	0

Depth (cm)

Coarse Fractions(mm)

˃2mm

Orgn

Total

Extr

Total

(-- Dith -Cit --)

Weight

Wt

C

N

P

S

Extractable

2-5

5-20

20-75

.1-75

Pct of

Fe

Al

Mn

Whole

6A1c

6B3a

6S3

6R3a

6C2b

6G7a

6D2a

Pct of ˂ 75mm (3B1)

Soil

Pct ˂ 2mm

g/kg

Pct of ˂ 2mm

0-13

4.25

13-42

3.51

42-72

3.47

72-101

3.79

101-160

1.36

Depth (cm)

Ratio/Clay

Atterberg

( Bulk Density )

COLE

(- Water Content -)

WRD

CEC

1500

Limits

Field

33

Oven

Whole

Field

10

33

1500

Whole

kPa

LL

PI

Moist

kPa

Dry

Soil

Moist

kPa

kPa

kPa

Soil

8D1

8D1

4P1

4P

4A3a

4A1d

4A1h

4D1

4B4

4B1c

4B1c

4B2a

4C1

Pct ˂0.4mm

- - g/cc - -

cm/cm

-- Pct of ˂2mm --

cm/cm

0-13

1.2

0.67

64.6

13-42

1.0

0.80

62.0

42-72

1.0

0.78

68.8

72-101

1.0

101-160

0.6

Depth (cm)	( NH4OAc Extractable Bases )					Acid-	Extr	(----- CEC -----)			Al
	Ca	Mg	K	Na	Sum	ity	Al	Sum	NH4-	Bases	Sat
	5B5a	5B5a	5B5a	5B5a	Bases			Cats	OAc	+ Al
	6N2e	6O2d	6Q2b	6P2b		6H5a	6G9a	5A3a	5A8b	5A3b	5G1
	- - - - - - - - - - - - meq / 100g - - - - - - - - - - - -										Pct
0-13	2.3	0.9	0.8	0.17	4.2	34.3	0.3	38.4	30.3	4.5	7.1
13-42	1.9	1.1	0.2	0.1	3.3	34.8	0.6	38.2	28.7	3.7	14.7
42-72	2.1	1.2	0.2	0.1	3.6	34.9	0.4	38.5	28.8	4.0	9.6
72-101	1.9	1.2	0.2	0.1	3.4	38.3	0.3	41.7	28.8	3.7	8.1
101-160	2.9	1.7	0.1	0.3	5.0	26.6	0	31.5	24.8	5.0	0

Depth (cm)	(Base Sat)		CO3 as	Res	P Ret	(------ pH ------)				Acid Oxalate Extraction
	Sum	NH4-	CaCO3			NaF	KCl	CaCl2	H2O	Opt	Al	Fe	Si
		OAc	˂2mm					.01M		Den
	5C3	5C1	6E1g	8E1		8C1d		8C1f	8C1f	8J	6G12	6C9a	6V2
	---- Pct ----			ohms/cm	Pct		1: 1	1: 2	1: 1		- Pct of ˂2mm -
0-13	10.8	13.7			95.5		4.6	5.0	5.7		2.31	2.20	0.41
13-42	8.7	11.6			93.0		4.6	4.9	5.8		2.25	2.25	0.40
42-72	9.4	12.6			94.9		4.6	5.0	5.9		2.24	2.21	0.38
72-101	8.2	11.9			96.7		4.6	5.0	5.9		2.29	2.27	0.39
101-160	15.8	20.1			91.6		4.6	5.2	6.4		1.68	2.26	0.35