Reference soil Ecuador 20: Andosol

EC020

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 EC020: Andosols

EC20 is similar to profile Ecuador 4 in: part III - tourguide for Ecuador of the sixth inernational soil classification workshop (1984). In june 1987 the soil was resampled by G.del Posso, additionally two monoliths with a length of 140cm were taken.

Classification

WRB 2006

WRB 1998

Umbric-Vitric- Andosol (Endoeutric Endoskeletic)

Umbri-Vitric- Andosol (Endoskeletic Endoeutric)

0-47 cm	umbric horizon
-	vitric

0-47 cm	umbric horizon
0-47 cm	vitric horizon

FAO-UNESCO-ISRIC 1988

FAO-UNESCO-ISRIC 1974

Umbri-Vitric Andosol

Humic Andosol

0-47 cm	umbric A horizon
-	andic

0-47 cm	umbric A horizon
-	exchange complex dominated by amorphous material

Local classification:	Suelos cascajozos

Other classification

USDA-SCS (1975)

Vitrandept udic sandy-skeletal over loamy isomesic

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	1.5	6.1	12.0	19.8	11.2	50.6	14.6	25.4	40.0	9.6
25-47	25	8.5	13.6	17.0	18.7	9.5	67.3	10.6	15.2	25.8	6.9
47-65	42	17.6	29.5	27.7	16.6	3.8	95.2	1.3	2.5	3.8	1.0
65-85	68	29.3	37.4	25.7	4.3	0.5	97.2	0.0	2.1	2.1	0.8
85-147	75	33.0	44.5	16.9	2.0	0.4	96.8	0.6	2.2	2.8	0.3
147-170	42	2.1	5.1	6.6	15.1	13.1	42.0	17.6	28.1	45.7	12.4

Water retention characteristics

Depth (cm)	Bulk density kg/dm³	Spec. Surf. Area m²/g	COLE cm/cm	Water disp. clay %	Clay % w/w
0-25	-	-	-	8.9	9.6
5-20	1.040	-	-	-	-
25-47	-	-	-	6.3	6.9
45-60	0.930	-	-	-	-
47-65	-	-	-	1.0	1.0
65-85	-	-	-	0.0	0.8
85-147	-	-	-	0.0	0.3
147-170	-	-	-	12.5	12.4

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
5-20	1.040	58.3	56.6	50.6	47.6	46.2	43.9	29.9	25.3
45-60	0.930	58.0	53.1	38.5	30.0	26.6	24.2	6.7	6.4

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	5.9	4.9	0.08	-	3.78	0.30	13	0.1	0	4.2	0.8	0.5	0.2	5.7
25-47	6.2	4.9	0.03	-	2.27	0.19	12	0.1	0	2.0	0.3	0.2	0.0	2.5
47-65	6.2	4.9	0.02	-	0.45	0.04	11	0.1	0	0.4	0.1	0.0	0.0	0.5
65-85	6.4	4.9	0.01	-	0.14	0.01	14	0.1	0	0.7	0.2	0.0	0.0	0.9
85-147	6.5	4.9	0.01	-	0.05	0	-	0.1	0	0.5	0.2	0.1	0.0	0.8
147-170	6.6	4.9	0.02	-	0.75	0.10	-	0	0	2.8	0.7	0.6	0.3	4.4

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	43	13.4	140	13.2	-	0	1
25-47	38	6.5	94	8.1	-	0	0
47-65	33	1.5	150	1.8	-	0	0
65-85	56	1.6	200	0.4	-	0	0
85-147	57	1.4	467	0.4	-	0	0
147-170	56	7.8	63	2.6	-	0	4

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	10.5	82	-	1.20	0.40	0.90	0.60	0.50	0.50	-	0.80
25-47	10.5	71	-	1.10	0.50	0.70	0.50	0.30	0.40	-	0.50
47-65	9.8	27	-	0.40	0.20	0.20	0.10	0.00	0.10	-	0.10
65-85	8.1	16	-	0.20	0.10	0.30	0.00	0.00	0.10	-	0.10
85-147	7.8	9	-	0.10	0.10	0.20	0.00	0.00	0.00	-	0.10
147-170	8.9	37	-	0.40	0.30	0.80	0.20	0.20	0.10	-	0.70

Clay mineralogy

Depth (cm)	Chlorite	Feldspar	Gibbsite	Goethite	Halloysite	Hematite	Kaolinite	Mica / illite	Mixed-layer	Quartz	Smec	Vermiculite
0-25	-	medium to strong	-	-	-	-	-	-	weak	-	-	-
25-47	-	medium to strong	-	-	-	-	-	-	weak	-	-	-
47-65	-	medium to strong	-	-	-	-	-	-	weak	-	-	-
65-85	-	medium to strong	-	-	-	-	-	-	medium to strong	-	-	-
85-147	-	weak	-	-	weak	-	-	-	very weak	-	-	-

Profile description

Ah 0-25 cm	very dark brown (10YR 2/2, moist)loam,weak medium subangular blocky and moderate medium granular,friable slightly sticky slightly plastic,few very fine medium tubular pores,gradual wavy boundary to,
AC 25-47 cm	(10YR 2/3, moist)sandy loam slightly gravelly,weak medium subangular blocky,very friable slightly sticky non plastic,many very fine interstitial pores and common tubular pores,clear wavy boundary to,
2C1 47-65 cm	(dark) brown (10YR 4/3, moist)coarse sand gravelly,structureless single grain,loose non sticky non plastic,many medium interstitial pores,clear wavy boundary to,
2C2 65-85 cm	pale yellow (2.5Y 7/4, moist)coarse sand gravelly,structureless single grain,loose,many very fine medium interstitial pores,clear wavy boundary to,
2C3 85-147 cm	light grey (10YR 7/2, moist)coarse sand very gravelly,structureless single grain,loose,many very fine medium interstitial pores,abrupt wavy boundary to,
3Ab 170- cm	(10YR 3/2.5, moist)silt loam slightly gravelly,weak coarse subangular blocky,friable slightly sticky slightly plastic moderately smeary,few fine prominent clear mottles (2.5 YR 3/4) and common fine prominent mottles (5 YR 3/3),common very fine tubular pores,

Depth1	47cm
Kind 1 (parent material) ; Parker (eds), 1984	acidic ash
Kind 2 (parent material) (second entry); Parker (eds), 1984	acidic ash
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	ash and pumice deposits
Soil Depth	110cm
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

Major crops	perennial crops
Land use or vegetation in the immediate vicinity of the site	medium level mixed farming
Remarks on Land Use / Vegetation	VEGETATION: Kikuyu grass and Pinus radiata LANDUSE: Native vegetation: temperate forest

Altitude	2780m
Physiographic Unit	slope
Physiographic position of the site	upper slope
Regional landform; McDonald, R.C., Isbell, R.F. et all, 1984; Australian soil and land survey Field Handbook, Inkata Press, Melbourne.	mountain
Slope	25%
Slope Aspect	north
Form of the slope surrounding the site	convex
Topography; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	mountainous

Drainage class ; FAO (2006) - Guidelines for soil description	somewhat excessive
Flooding frequency (FAO, 1986)	never
Kind of ground water table (USDA, 1979)	no groundwater table observed
Moist From - To	0-170cm
Estimated permeability (class) of least permeable part of the profile	high
Estimated run off (class)	rapid

Evidence of alkali ; Soil Survey Manual USDA, 1951	non-alkaline
Surface cracking	no cracks observed
Slaking of aggregates by tillage, rainfall or frost (USDA/SCS, 1979)	no surface slaking/crusting observed
Rock outcrop class (FAO (2006) - Guidelines for soil description)	none
Evidence of salt; Soil Survey Manual USDA, 1951	non-saline
Surface stoniness class (FAO (2006) - Guidelines for soil description)	none

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Reference soil Ecuador 20: Andosol

Characteristics

Reference soil EC020: Andosols

Classification