Reference soil Colombia 13: Andosol

CO013

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 CO013: Andosols

CLIMATE: The climate may vary considerably over short distances because of varied topography. Calhoen (1971) gives the following information on general climate variations in the Pasto area: altitude (m) rainfall (mm) temperature (Celsius) 3100 9-12 2750 781 13 2670 700 13 1400 1392 20 ( 0 2849 26 ) The site is influenced by cold wet winds blowing from the "Laguna la Cocha". LAND USE AND VEGETATION: Crops grown in vicinity are Eucalyptus and Pinus. ADDITIONAL NOTES ON PROFILE DESCRIPTION: BC - the mottles occur along rootchannels Bir - placic; acts as a pan and upholds water, resulting in seepage just above the horizon.

Classification

WRB 2006

WRB 1998

Hydric-Silandic-Epivitric- Andosol (Hyperdystric Placic Thixotropic)

Sili-Vitric- Andosol (Hydric Umbrihumic)

0-30 cm	folic horizon
30-78 cm	umbric horizon
-	vitric
-	andic

0-30 cm	vitric horizon
0-30 cm	folic horizon
30-78 cm	umbric horizon
30-98 cm	andic horizon
-	strongly humic

FAO-UNESCO-ISRIC 1988

FAO-UNESCO-ISRIC 1974

Placi-Umbric Andosol

Humic Andosol

0-78 cm	umbric A horizon
-	andic
-	smeary consistence

0-78 cm	umbric A horizon
-	exchange complex dominated by amorphous material
-	smeary consistence

Other classification

USDA-NRCS (1999)

Typic Placudand

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
0-12	-	0.9	1.4	2.4	7.2	8.4	20.3	15.3	44.3	59.6	20.2
12-30	-	0.3	1.0	1.9	4.6	7.2	15.0	17.5	43.5	61.0	23.9
30-51	-	0.6	1.4	4.6	7.1	14.0	27.7	18.0	37.9	55.9	16.5
51-78	-	0.4	0.9	2.5	9.8	12.6	26.2	8.1	33.4	41.5	32.4
78-82	42	0.2	0.7	1.6	11.4	13.1	27.0	10.4	25.9	36.3	36.6
82-98	-	0.1	0.2	1.3	16.9	15.9	34.4	6.0	31.1	37.1	28.4
98-120	-	0.1	0.2	2.1	17.7	13.9	34.0	6.3	36.9	43.2	22.8
120-150	-	0.1	3.9	11.3	12.5	7.9	35.7	6.5	21.5	28.0	35.7

Water retention characteristics

Depth (cm)	Bulk density kg/dm³	Spec. Surf. Area m²/g	COLE cm/cm	Water disp. clay %	Clay % w/w
0-12	-	-	-	-	20.2
12-30	-	-	-	-	23.9
30-51	-	-	-	-	16.5
51-78	-	-	-	-	32.4
78-82	-	-	-	-	36.6
82-98	-	-	-	-	28.4
98-120	-	-	-	-	22.8
120-150	-	-	-	-	35.7

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
0-12	4.4	3.3	0.38	-	46.22	-	-	-	-	6.0	2.6	1.0	0.0	9.6
12-30	4.0	3.6	0.55	-	28.55	-	-	-	-	0.6	1.1	0.2	0.0	1.9
30-51	4.9	4.2	0.08	-	13.06	0.42	31	3.0	2.2	0.8	0.7	3.0	0.0	4.5
51-78	5.0	4.2	0.06	-	15.75	0.55	29	2.8	2.2	0.0	0.0	0.1	0.0	0.1
78-82	4.8	4.3	0.07	-	14.25	0.47	30	1.5	1.1	0.5	0.8	0.0	0.0	1.3
82-98	5.2	4.6	0.04	-	8.47	0.26	33	0.5	0.2	0.0	0.0	0.0	0.0	0.0
98-120	5.4	5.1	0.07	-	2.44	0.11	22	0.2	0	0.7	0.6	0.2	0.0	1.5
120-150	5.4	4.9	0.03	-	3.44	0.16	22	0.2	0	0.4	0.7	0.3	0.0	1.4

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 %
0-12	5	179.2	887	161.8	-	-	0
12-30	2	105.0	439	99.9	-	-	0
30-51	7	66.3	402	25.2	-	3	0
51-78	0	121.7	376	38.5	-	2	0
78-82	1	116.9	319	32.9	-	1	0
82-98	0	77.3	272	18.2	-	0	0
98-120	3	45.4	199	7.7	-	0	0
120-150	3	51.3	144	11.2	-	0	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
0-12	6.9	51	-	0.73	0.09	0.35	0.72	0.34	0.53	-	0.40
12-30	8.0	80	-	1.01	0.07	0.61	1.42	0.63	0.93	-	0.67
30-51	10.8	98	-	2.62	0.40	0.21	2.04	0.14	2.39	-	0.13
51-78	10.9	99	-	7.09	1.63	0.49	5.68	0.44	2.67	-	0.53
78-82	10.8	99	-	8.54	2.52	4.74	6.10	2.96	2.10	-	5.09
82-98	10.9	99	-	8.00	2.77	1.35	4.09	0.00	1.32	-	1.11
98-120	10.8	99	-	5.75	2.58	0.38	0.82	0.06	0.43	-	0.34
120-150	10.7	99	-	6.06	2.67	0.61	0.95	0.07	0.53	-	0.56

Profile description

Oa1 0-12 cm	dark reddish brown (5YR 2.5/2, moist)loam,very weak fine subangular blocky to massive,very friable non sticky non plastic moderately smeary,many fine tubular pores and many tubular pores,gradual wavy boundary to,
Oa2 12-30 cm	black (5YR 2.5/1, moist)loam,very weak fine subangular blocky to massive,very friable non sticky non plastic moderately smeary,many fine tubular pores and many tubular pores,gradual wavy boundary to,
30-51 cm	dark brown (7.5YR 3/2, moist)loam,very weak fine subangular blocky to massive,very friable non sticky non plastic moderately smeary,common fine pores and common pores,gradual wavy boundary to,
Bh 51-78 cm	very dark grey (10YR 3/1, moist)loam,very weak fine subangular blocky to massive,very friable non sticky non plastic moderately smeary,common fine pores and common pores,abrupt wavy boundary to,
Bsm 78-82 cm	reddish brown (5YR 4/3, moist)loam,strong medium platy,firm non sticky non plastic,no pores,abrupt wavy boundary to,
82-98 cm	very dark grey (10YR 3/1, moist)loam,massive,very friable non sticky non plastic moderately smeary,few medium faint diffuse mottles (10 YR 5/6),few fine pores,abrupt broken boundary to,
C1 98-120 cm	brownish yellow (10YR 6/6, moist)loam,massive,very friable non sticky non plastic moderately smeary,common medium distinct mottles (5 YR 5/8),abrupt wavy boundary to,
C2 120-150 cm	yellowish brown (10YR 5/4, moist)loam,massive,very friable non sticky non plastic moderately smeary,few medium distinct mottles (5 YR 5/8),

Kind 1 (parent material) ; Parker (eds), 1984	ejecta ash
Mode of accumulation or deposition of parent material	unconsolidated, unspecified
Remarks on Parent Materials	lava, ash, tuff

Land use or vegetation in the immediate vicinity of the site	(semi-)natural vegetation
Remarks on Land Use / Vegetation	VEGETATION: Bosque humido muy humido LANDUSE: In the vicinity Eucalyptus and Pinus are grown
Major vegetation type; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	closed forest

Altitude	3240m
Physiographic Unit	volcanic upland
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.	volcano
Slope	25%
Slope Aspect	north-east
Form of the slope surrounding the site	straight
Topography; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	steeply dissected

Drainage class ; FAO (2006) - Guidelines for soil description	moderately well
Kind of ground water table (USDA, 1979)	no groundwater table observed
Moist From - To	0-150cm
Estimated permeability (class) of least permeable part of the profile	high
Estimated run off (class)	very rapid

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 Colombia 13: Andosol

Characteristics

Reference soil CO013: Andosols

Classification