Reference soil Ecuador 08: Andosol

EC008

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 EC008: Andosols

See also information of profile Ecuador 11 in partII: tour guide for Ecuador of the sixth international soil classification workshop(1984). The profile was resampled in May 1987 by G.del Posso, two additional monoliths of 140cm length were taken. In the A1 and A2 horizons about 1% fragments of brick, stone, artefacts and charcoal are present. The upper part of the 2C1 horizon has been stained black (10YR2/1).

Classification

WRB 2006

WRB 1998

Umbric-Mollic-Vitric- Andosol

Dystri-Mollic- Cambisol

0-25 cm	mollic horizon
25-57 cm	umbric horizon
57-84 cm	mollic horizon
-	vitric

0-25 cm	mollic horizon
25-57 cm	umbric horizon
57-84 cm	mollic horizon

FAO-UNESCO-ISRIC 1988

FAO-UNESCO-ISRIC 1974

Molli-Humic Cambisol

Humic Cambisol

0-25 cm	mollic A horizon
25-57 cm	umbric A horizon
57-84 cm	mollic A horizon
-	strongly humic

0-25 cm	mollic A horizon
25-57 cm	umbric A horizon
57-84 cm	mollic A horizon

Local classification:	Suelo Negro Andino

Other classification

USDA-SCS (1975)

Humitropept perudic coarse-loamy over sandy/sandy-skeletal mixed isohyperthermic

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
0-25	0	0.3	2.0	10.1	19.8	11.8	44.0	15.8	28.3	44.1	11.9
25-57	0	0.2	1.8	7.5	20.2	13.2	42.9	16.4	31.5	47.9	9.1
57-84	0	2.1	9.7	18.4	19.7	10.1	60.0	11.0	17.7	28.7	11.2
84-120	14	10.0	32.9	40.0	10.5	0.9	94.3	1.5	2.9	4.4	1.4
120-133	0	1.1	4.2	15.0	26.2	10.9	57.4	14.9	19.5	34.4	8.1

Water retention characteristics

Depth (cm)	Bulk density kg/dm³	Spec. Surf. Area m²/g	COLE cm/cm	Water disp. clay %	Clay % w/w
20-30	0.900	-	-	-	-
0-25	-	-	-	7.3	11.9
25-57	-	-	-	1.7	9.1
50-60	0.990	-	-	-	-
57-84	-	-	-	3.1	11.2
110-120	1.140	-	-	-	-
84-120	-	-	-	1.6	1.4
120-133	-	-	-	2.1	8.1

Other physical data

Depth (cm)	Bulk density kg/dm³	pF 0 % v/v	pF 1.0 % v/v	pF 1.5 % v/v	pF 2.0 % v/v	pF 2.3 % v/v	pF 2.7 % v/v	pF 3.4 % v/v	pF 4.2 % v/v
20-30	0.900	60.9	60.6	59.9	53.2	49.7	45.3	25.1	19.0
50-60	0.990	58.5	58.3	55.4	50.3	47.6	43.5	27.6	20.9
110-120	1.140	54.1	53.9	49.4	43.2	40.4	35.7	7.6	6.2

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
0-25	5.8	5.0	0.22	-	5.12	0.44	12	0.1	0	9.0	1.2	0.5	0.0	10.7
25-57	6.4	5.0	0.04	-	2.67	0.20	13	0.1	0	3.1	0.5	0.6	0.0	4.2
57-84	6.8	5.2	0.06	0.6	3.12	0.22	14	0.1	0	3.8	0.4	1.1	0.0	5.3
84-120	6.8	5.2	0.03	0.5	0.20	0.02	10	0.1	0	0.5	0.1	0.1	0.0	0.7
120-133	6.7	5.0	0.02	0.1	1.18	0.07	17	0	0	2.5	0.4	0.1	0.1	3.1

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 %
0-25	75	14.3	120	17.9	-	0	0
25-57	47	8.9	98	9.5	-	0	0
57-84	52	10.2	91	10.9	-	0	0
84-120	33	2.1	150	0.7	-	0	0
120-133	52	6.0	74	4.2	-	0	2

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
0-25	-	71	-	0.90	0.30	0.70	0.50	0.50	0.60	-	0.50
25-57	-	68	-	0.90	0.40	0.60	0.40	0.20	0.40	-	0.40
57-84	-	78	-	1.60	0.90	0.80	0.50	0.10	0.40	-	0.50
84-120	-	21	-	0.30	0.20	0.20	0.10	0.00	0.10	-	0.10
120-133	-	49	-	1.10	0.70	0.50	0.20	0.00	0.20	-	0.20

Clay mineralogy

Depth (cm)	Chlorite	Feldspar	Gibbsite	Goethite	Halloysite	Hematite	Kaolinite	Mica / illite	Mixed-layer	Quartz	Smec	Vermiculite
0-25	-	weak	-	-	-	-	-	-	weak	very weak	-	-
25-57	-	weak	-	-	-	-	weak	-	medium to strong	very weak	-	-
57-84	-	weak	-	-	-	-	very weak	-	-	very weak	-	-
84-120	-	weak	-	-	-	-	-	-	-	-	-	-
120-133	-	weak	-	-	-	-	-	-	very weak	-	-	-

Profile description

Ah1 0-25 cm	black (10YR 2/1, moist)loam,moderate medium and coarse subangular blocky parting to moderate moderate to strong granular,friable non sticky non plastic,many very fine tubular pores and common tubular pores,very few charcoal inclusions and very few pottery inclusions,very few fine gravel pumice fragments,gradual wavy boundary to,
Ah2 25-57 cm	black (10YR 2/1, moist)loam,weak medium and coarse subangular blocky parting to weak coarse granular,friable non sticky non plastic,many very fine tubular pores and common interstitial pores,very few charcoal inclusions and very few pottery inclusions,very few fine gravel pumice fragments,diffuse wavy boundary to,
Ah3 57-84 cm	(10YR 2/no, moist)loam,weak coarse subangular blocky,friable non sticky non plastic,patchy thin humus on pedfaces cutans,many very fine tubular pores and few interstitial pores,few fine gravel pumice fragments,clear wavy boundary to,
2C 84-120 cm	(dark) brown (10YR 4/3, moist)coarse sand gravelly,structureless single grain,loose non sticky non plastic,many very fine interstitial pores,frequent fine gravel pumice fragments,clear wavy boundary to,
3Ab 120-133 cm	very dark greyish brown (10YR 3/2, moist)loam,weak coarse subangular blocky,friable non sticky non plastic,many very fine tubular pores and common interstitial pores,very few fine gravel pumice fragments,

Depth1	84cm
Kind 1 (parent material) ; Parker (eds), 1984	pyroclastic, unconsolidated
Kind 2 (parent material) (second entry); Parker (eds), 1984	pyroclastic, unconsolidated
Mode of accumulation or deposition of parent material	ejecta ash
Mode of accumulation or deposition of parent material (second entry)	ejecta ash
Remarks on Parent Materials	multiple ash/pumice
Soil Depth	200cm
Texture of parent material	loamy
Texture of parent material (second entry)	sandy
Weathering Resistance	poor
Weathering Resistance (second entry)	poor
General characterization of the status of weathering of solid rock	slightly
General characterization of the status of weathering of solid rock (second entry)	slightly

Land use or vegetation in the immediate vicinity of the site	cultivated pasture
Remarks on Land Use / Vegetation	VEGETATION: forest cleared and planted with pasture LANDUSE:
Major vegetation type; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	evergreen forest

Altitude	1500m
Physiographic Unit	hillslope
Physiographic position of the site	slope
Regional landform; McDonald, R.C., Isbell, R.F. et all, 1984; Australian soil and land survey Field Handbook, Inkata Press, Melbourne.	mountain
Slope	45%
Slope Aspect	north-east
Form of the slope surrounding the site	convex
Topography; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	steeply dissected

Drainage class ; FAO (2006) - Guidelines for soil description	well
Flooding frequency (FAO, 1986)	never
Kind of ground water table (USDA, 1979)	no groundwater table observed
Estimated permeability (class) of least permeable part of the profile	high
Estimated run off (class)	rapid
Wet From To	0-200cm

Evidence of alkali ; Soil Survey Manual USDA, 1951	non-alkaline
Evidence of salt; Soil Survey Manual USDA, 1951	non-saline

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Reference soil Ecuador 08: Andosol

Characteristics

Reference soil EC008: Andosols

Classification