Reference soil United States of America 06: Andosol

US006

Andosols occur throughout the world where volcanic activity is common, especially in the circum-Pacific region and along the mid-Atlantic Ridge.

Characteristics

Soils with a vitric or andic horizon (slightly to moderately weathered horizons in pyroclastic deposits dominated by short-range-order minerals, notably allophane and imogolite) starting within 25 cm from the soil surface. In addition, they may have a histic, fulvic, melanic, mollic, umbric, ochric, duric, or cambic horizon. Other diagnostic horizons (unless buried deeper than 50 cm by volcanic deposits) are absent.

Distribution of Andosols (rough estimation supplied by soilgrids)

Reference soil US006: Andosols

LAND USE: formerly sugarcane, presently under experimental maize and vegetable crops

Classification

WRB 1998

Hyperdystri-Hydric- Andosol

FAO-UNESCO-ISRIC 1988

FAO-UNESCO-ISRIC 1974

Hyperdystri-Haplic Andosol

Ochric Andosol

Local classification:	Kukaiau silty clay loam

Other classification

USDA-NRCS (1999)	Typic Hydrudand
USDA-SCS (1975)	Typic Dystrandept udic thixotropic isothermic

Physical characteristics

Particle size distribution

Depth (cm)	Gravel % v/v	very coarse sand % w/w	coarse sand % w/w	medium sand % w/w	fine sand % w/w	very fine sand % w/w	Total sand % w/w	coarse silt % w/w	fine silt % w/w	Total silt % w/w	Clay % w/w
0-17	-	0.7	1.3	1.5	4.5	4.9	12.9	11.7	34.3	46	41
17-31	-	0.5	0.7	0.6	1.6	1.8	5.2	10.9	38.5	49.4	45.4
31-49	-	0	0.1	0.1	0.3	0.6	1.1	4.7	39.2	43.9	55
49-60	-	0	0	0.1	0.2	0.2	0.5	6.6	35.6	42.2	57.1
60-76	-	0	0.1	0.1	0.4	0.3	0.9	5.5	35	40.5	58.8
76-94	-	0	0	0.1	0.3	0.3	0.7	4.5	37.7	42.2	57.2
94-113	-	0	0.1	0.1	0.3	0.3	0.8	6	31.3	37.3	61.9
113-150	-	0	0	0.1	0.6	0.6	1.3	3.7	29.2	32.9	65.8

Water retention characteristics

Depth (cm)	Bulk density kg/dm³	Spec. Surf. Area m²/g	COLE cm/cm	Water disp. clay %	Clay % w/w
0-17	-	-	-	-	41
17-31	-	-	-	-	45.4
31-49	-	-	-	-	55
49-60	-	-	-	-	57.1
60-76	-	-	-	-	58.8
76-94	-	-	-	-	57.2
94-113	-	-	-	-	61.9
113-150	-	-	-	-	65.8

Chemical data

Depth (cm)	pH H2O	pHKCl	EC 1: 2.5 dS/m	CaCO3 % w/w	C % w/w	N %	C / N	Exch. Acid cmol(c)/kg	Exch. Al cmol(c)/kg	Ca cmol(c)/kg	Mg cmol(c)/kg	K cmol(c)/kg	Na cmol(c)/kg	Sum Cations cmol(c)/kg
0-17	5.1	4.8	0.12	-	9.21	-	-	-	0.3	0.3	0.0	0.2	0.0	0.5
17-31	5.2	5.0	0.09	-	7.91	-	-	-	0.1	0.0	0.0	0.1	0.0	0.1
31-49	5.9	5.5	0.07	-	5.73	-	-	-	0.1	0.5	0.0	0.1	0.0	0.6
49-60	6.1	5.6	0.06	-	5.96	-	-	-	0	0.5	0.0	0.1	0.0	0.6
60-76	6.1	5.7	0.07	-	5.35	-	-	-	0.1	1.0	0.0	0	0.0	1.0
76-94	6.2	5.7	0.07	-	4.83	-	-	-	0.1	1.0	0.0	0.1	0.0	1.1
94-113	6.2	5.6	0.07	-	3.11	-	-	-	0.1	1.7	0.0	0.3	0.0	2
113-150	6.1	5.6	0.08	-	4.40	-	-	-	0.1	2.0	0.0	0.1	0.0	2.1

Depth (cm)	Base sat. %	CEC soil cmol(c)/kg	CEC clay cmol(c)/kg	CEC org cmol(c)/kg	ECEC cmol(c)/kg	Al sat. %	ESP %
0-17	1	60.3	147	32.2	-	0	-
17-31	0	58.3	128	27.7	-	0	-
31-49	1	65.6	119	20.1	-	0	-
49-60	1	69.6	122	20.9	-	0	-
60-76	1	70.8	120	18.7	-	0	-
76-94	2	60.1	105	16.9	-	0	-
94-113	5	41.1	66	10.9	-	0	-
113-150	3	66.5	101	15.4	-	0	-

Depth (cm)	pH NaF	P Retention %	ODOE	Al o % w/w	Si o % w/w	Fe d % w/w	Al d % w/w	Fe p % w/w	Al p % w/w	C p % w/w	Fe o % w/w
0-17	10.3	99	-	5.99	0.93	8.04	4.61	1.82	1.9	-	7.05
17-31	10.4	100	-	5.49	1.01	9.38	5.13	2.48	1.9	-	7.18
31-49	10.4	84	-	7.44	1.98	9.56	4.99	1.33	1.04	-	7.95
49-60	10.5	100	-	9.69	2.86	9.93	5.49	0.78	0.91	-	8.1
60-76	10.5	100	-	9.75	2.75	10.7	5.21	0.68	0.79	-	8.36
76-94	10.4	100	-	8.23	2.1	10.6	5.57	1.09	0.76	-	9.29
94-113	10.3	100	-	5.78	1.44	12.1	5.07	2.39	1.02	-	7.65
113-150	10.4	100	-	8.59	2.57	6.65	5.3	0.96	0.81	-	7.45

Clay mineralogy

Depth (cm)	Chlorite	Feldspar	Gibbsite	Goethite	Halloysite	Hematite	Kaolinite	Mica / illite	Mixed-layer	Quartz	Smec	Vermiculite
0-17	-	-	strong	-	-	-	weak to medium	very weak to weak	-	weak to medium	weak to medium	-
31-49	-	-	strong	-	-	-	weak to medium	weak	-	medium to strong	weak to medium	-
60-76	-	-	strong	-	-	-	weak	weak	-	medium to strong	weak to medium	-
94-113	-	-	strong	-	-	-	weak to medium	weak	-	medium to strong	weak to medium	-

Profile description

Ap1 0-17 cm	dark reddish brown (5YR 3/3, moist)silty clay loam,weak fine and medium subangular blocky,friable slightly sticky slightly plastic,many very fine pores,many very fine roots,clear smooth boundary to,
Ap2 17-31 cm	(5YR 3/3.5, moist)silty clay loam,weak fine and medium subangular blocky,friable slightly sticky slightly plastic,many very fine pores,many very fine roots,abrupt smooth boundary to,
Bw1 31-49 cm	dark reddish brown (5YR 3/3, moist)silty clay loam,weak fine and medium subangular blocky,friable sticky plastic weakly smeary,continuous moderately thick humus in root channels and pores cutans,many very fine pores and few medium pores,common very fine roots,gradual smooth boundary to,
Bw2 49-60 cm	dark reddish brown (5YR 3/3, moist)silty clay loam slightly gravelly,moderate fine and medium subangular blocky,friable slightly sticky plastic weakly smeary,continuous moderately thick humus in root channels and pores cutans,many very fine pores and few medium pores,few very fine roots,few medium and coarse gravel weathered cinders fragments,clear smooth boundary to,
Bw3 60-76 cm	(5YR 3/3.5, moist)silty clay loam,moderate fine and medium subangular blocky,friable sticky plastic weakly smeary,continuous moderately thick humus in root channels and pores cutans,many very fine pores and few pores,few very fine roots,clear smooth boundary to,
Bw4 76-94 cm	dark reddish brown (5YR 3/4, moist)silty clay loam,moderate fine and medium subangular blocky and moderate coarse subangular blocky,friable sticky plastic weakly smeary,continuous moderately thick humus in root channels and pores cutans,many very fine pores and few pores,few very fine roots,clear smooth boundary to,
Bw5 94-113 cm	(5YR 3/3.5, moist)silty clay loam,moderate fine and medium subangular blocky,friable sticky plastic weakly smeary,continuous moderately thick humus in root channels and pores cutans,many very fine pores and few pores,few very fine roots,clear smooth boundary to,
Bw6 113-150 cm	yellowish red (5YR 4/6, moist)silt loam,moderate fine and medium subangular blocky,friable slightly sticky slightly plastic moderately smeary,broken thin humus on pedfaces cutans,many very fine pores and few pores,few very fine roots,gradual smooth boundary to,

Kind 1 (parent material) ; Parker (eds), 1984	andesite
Mode of accumulation or deposition of parent material	ejecta ash
Remarks on Parent Materials	andesitic ash
Texture of parent material (second entry)	loamy
Weathering Resistance	poor
General characterization of the status of weathering of solid rock	partially or moderately

Major crops	maize
Land use or vegetation in the immediate vicinity of the site	arable farming

Altitude	395m
Regional landform; McDonald, R.C., Isbell, R.F. et all, 1984; Australian soil and land survey Field Handbook, Inkata Press, Melbourne.	volcano
Slope	6%
Topography; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	rolling

Drainage class ; FAO (2006) - Guidelines for soil description	well
Flooding frequency (FAO, 1986)	never
Moist From - To	0-163cm
Estimated permeability (class) of least permeable part of the profile	high
Estimated run off (class)	rapid

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Reference soil United States of America 06: Andosol

Characteristics

Reference soil US006: Andosols

Classification