Reference soil Costa Rica 07: Andosol

CR007

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 CR007: Andosols

Brief soil description: Moderately deep, well drained, dark brown to brown loamy over sandy soil, well structured. On the boundary of Ah1 to Ah2 a 'panlike structure' is found altough no compaction was found. The structure can be recognized as a grey band with rust coloured edges. Abundant soil fauna: ants, earthworms, termites, jumptails, beetles. Actual classification: FAO (1988): Umbric Andosol USDA (1992): Acrudoxic Hapludand

Classification

WRB 2006

WRB 1998

Umbric-Aluandic-Vitric- Andosol (Dystric)

Pachi-Vitric- Andosol (Umbric Dystric)

0-80 cm	umbric horizon
-	andic
-	vitric

0-80 cm	andic horizon
0-80 cm	umbric horizon
80-135 cm	vitric horizon

FAO-UNESCO-ISRIC 1988

FAO-UNESCO-ISRIC 1974

Orthi-Umbric Andosol

Humic Andosol

0-80 cm	umbric A horizon
-	andic

0-80 cm	umbric A horizon
-	exchange complex dominated by amorphous material

Local classification:	Suelo Los Diamantes

Other classification

USDA-SCS (1975)

Dystrandept perudic coarse-loamy over sandy/sandy-skeletal 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	1.7	6.4	15.5	26.1	9.1	58.8	9.9	18.4	28.3	12.8
25-80	0	1.9	6.6	16.2	29.9	13.2	67.8	11.2	16.1	27.3	4.9
80-90	0	2.6	8.6	22.0	33.7	10.3	77.2	7.9	12.1	20.0	2.8
90-135	0	2.2	19.5	45.9	24.7	3.5	95.8	0.0	2.6	2.6	1.5

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	-	-	-	3.1	12.8
0-15	0.749	-	-	-	-
25-80	-	-	-	2.1	4.9
15-60	0.690	-	-	-	-
75-80	0.766	-	-	-	-
80-90	-	-	-	3.0	2.8
90-135	-	-	-	2.4	1.5

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
0-15	0.749	65.3	60.2	51.2	46.2	44.1	43.0	38.2	36.4
15-60	0.690	68.7	64.7	48.5	40.1	37.9	36.5	31.8	30.9
75-80	0.766	65.0	62.9	52.8	44.9	43.2	40.3	37.6	36.2

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	5.3	4.8	0.24	-	6.42	0.68	9	0.3	0	6.8	1.8	0.3	0.1	9.0
25-80	5.6	5.3	0.03	-	1.55	0.17	9	-	-	0.8	0.0	0.0	0.1	0.9
80-90	5.7	5.3	0.02	-	0.58	0.07	8	-	-	1.4	0.3	0.1	0.1	1.9
90-135	5.9	4.9	0.01	-	0.06	0.01	6	-	-	0.6	0.2	0.1	0.0	0.9

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	21.0	164	22.5	-	0	0
25-80	15	5.9	120	5.4	-	-	2
80-90	35	5.4	193	2.0	-	-	2
90-135	32	2.8	-	0.2	-	-	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
0-25	-	-	-	2.01	0.18	-	-	-	-	-	0.69
25-80	-	-	-	2.26	0.18	-	-	-	-	-	0.62
80-90	-	-	-	1.52	0.24	-	-	-	-	-	0.42
90-135	-	-	-	0.42	0.12	-	-	-	-	-	0.61

Clay mineralogy

Depth (cm)	Chlorite	Feldspar	Gibbsite	Goethite	Halloysite	Hematite	Kaolinite	Mica / illite	Mixed-layer	Quartz	Smec	Vermiculite
0-25	-	very weak	-	-	-	-	very weak	-	very weak	-	-	-
25-80	-	very weak	-	-	-	-	very weak	-	very weak	-	-	-
80-90	-	very weak	-	-	-	-	very weak	-	very weak	-	-	-
90-135	-	very weak	-	-	-	-	very weak	-	very weak	-	-	-

Profile description

Ah1 0-25 cm	very dark brown (10YR 2/2, moist)sandy loam,strong medium crumb,very friable non sticky non plastic,many fine to coarse continuous exped and inped tubular random pores highly porous (>60 vol%),clear smooth boundary to,
Ah2 25-80 cm	dark brown (10YR 3/3, moist)sandy loam,weak medium and coarse subangular blocky,very friable non sticky non plastic,many very fine continuous exped and inped tubular random pores and many continuous exped and inped tubular random pores highly porous (>60 vol%),gradual smooth boundary to,
B 80-90 cm	dark brown (10YR 3/3, moist)loamy sand,weak medium and coarse angular blocky,friable non sticky non plastic,many very fine continuous exped and inped tubular random pores and many continuous exped and inped tubular random pores highly porous (>60 vol%),abrupt smooth boundary to,
C 90-135 cm	very dark brown (10YR 2/2, moist)Description sand,structureless,loose loose non sticky non plastic,many fine continuous interstitial random pores highly porous (>60 vol%),abrupt wavy boundary to,
2Bb 135-150 cm	dark brown (10YR 3/3, moist)loamy sand,weak medium angular blocky,very friable non sticky non plastic,common very fine continuous exped and inped tubular random pores and common continuous exped and inped tubular random pores moderately porous (40-60 v,

Kind 1 (parent material) ; Parker (eds), 1984	fine-grained intermediate igneous rock
Mode of accumulation or deposition of parent material	fluvial
Remarks on Parent Materials	andesitic origin
Soil Depth	90cm
Texture of parent material	sandy
Texture of parent material (second entry)	sandy
Weathering Resistance	poor
General characterization of the status of weathering of solid rock	slightly

Main type of irrigation; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	no irrigation
Land use or vegetation in the immediate vicinity of the site	(semi-)natural vegetation
Remarks on Land Use / Vegetation	VEGETATION: Forest strip of 50m width along river
Rotation scheme ; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	crop rotation scheme not relevant
Status of vegetation; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	cut over
Major vegetation type; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	closed forest

Altitude	240m
Physiographic Unit	river terrace on alluvial fan
Physiographic position of the site	middle slope
Regional landform; McDonald, R.C., Isbell, R.F. et all, 1984; Australian soil and land survey Field Handbook, Inkata Press, Melbourne.	alluvial fan
Slope	3%
Slope Aspect	south
Form of the slope surrounding the site	straight
Topography; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	undulating

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	0-150cm
Estimated permeability (class) of least permeable part of the profile	high
Estimated run off (class)	slow

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
Micro relief type: small-scale differences in relief in the direct vicinity of the site (FAO, 1986)	level
Microrelief pattern	none
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 Costa Rica 07: Andosol

Characteristics

Reference soil CR007: Andosols

Classification