Reference soil Costa Rica 06: Andosol

CR006

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 CR006: Andosols

Brief soil description: Moderately deep, well drained, dark brown to brown coarse loamy over sandy soil, well structured. Some pot splinters were found at about 30 cm depth indicating former indian activity at site. Between 30 and 60 cm abundant small balls of dung (?) were found originating from dung beetles. Actual classification: FAO (1988): Umbric Andosol USDA (1992): Vitric Hapludand

Classification

WRB 2006

WRB 1998

Umbric-Aluandic-Vitric- Andosol (Dystric)

Pachi-Vitric- Andosol (Umbric Dystric)

0-70 cm	umbric horizon
70-100 cm	calcic horizon
-	andic
-	vitric

0-70 cm	andic horizon
0-70 cm	umbric horizon
70-100 cm	cambic horizon
70-115 cm	vitric horizon
-	strongly humic

FAO-UNESCO-ISRIC 1988

FAO-UNESCO-ISRIC 1974

Humi-Umbric Andosol

Humic Andosol

0-70 cm	umbric A horizon
70-100 cm	cambic B horizon
-	andic
-	strongly humic

0-70 cm	umbric A horizon
70-100 cm	cambic B horizon
-	exchange complex dominated by amorphous material
-	thixotropy

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
0-7	0	1.2	4.2	15.8	28.2	12.1	61.5	8.5	27.9	36.4	2.1
7-20	0	1.3	3.7	12.7	34.2	11.2	63.1	9.2	26.6	35.8	1.2
20-70	0	0.8	2.0	14.5	38.4	15.6	71.3	8.2	20.6	28.8	0.0
70-100	0	1.1	3.6	15.2	47.5	12.6	80	8.2	8.6	16.8	3.1
100-115	0	0.2	1.3	16.9	59.2	11.6	89.2	4.5	3.6	8.1	2.7

Water retention characteristics

Depth (cm)	Bulk density kg/dm³	Spec. Surf. Area m²/g	COLE cm/cm	Water disp. clay %	Clay % w/w
0-7	-	-	-	1.6	2.1
5-10	0.563	-	-	-	-
50-55	0.849	-	-	-	-
7-20	-	-	-	3.7	1.2
82-87	1.014	-	-	-	-
20-70	-	-	-	2.5	0.0
70-100	-	-	-	0.0	3.1
100-115	-	-	-	2.4	2.7

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
5-10	0.563	71.9	63.9	56.8	53.5	52.3	48.9	35.1	34.6
50-55	0.849	60.9	59.2	49.4	39.2	37.0	33.2	27.4	26.9
82-87	1.014	54.6	52.7	41.3	32.2	30.9	28.1	20.7	20.1

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
0-7	4.2	4.7	0.18	-	5.10	0.65	8	0.4	0	6.0	2.5	0.3	0.3	9.1
7-20	5.5	4.8	0.08	-	3.99	0.46	9	-	-	4.7	1.1	0.1	0.1	6.0
20-70	5.8	5.1	0.03	-	1.76	0.18	10	-	-	3.0	0.7	0.2	0.3	4.2
70-100	6.0	5.3	0.02	-	0.53	0.04	13	-	-	1.9	0.3	0.2	0.1	2.5
100-115	6.2	5.2	0.02	-	0.20	0.02	10	-	-	1.9	0.4	0.1	0.0	2.4

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 %
0-7	53	17.1	814	17.9	-	0	2
7-20	37	16.2	-	14.0	-	-	1
20-70	47	9.0	-	6.2	-	-	3
70-100	45	5.5	177	1.9	-	-	2
100-115	53	4.5	167	0.7	-	-	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
0-7	10.0	80	-	1.77	0.14	-	-	0.40	0.60	-	1.01
7-20	10.7	73	-	1.72	0.08	-	-	0.40	0.60	-	0.81
20-70	10.8	72	-	2.08	0.18	-	-	0.10	0.40	-	0.59
70-100	10.3	48	-	1.06	0.08	-	-	0.00	0.20	-	0.45
100-115	9.8	34	-	0.81	0.17	-	-	0.00	0.10	-	0.58

Clay mineralogy

Depth (cm)	Chlorite	Feldspar	Gibbsite	Goethite	Halloysite	Hematite	Kaolinite	Mica / illite	Mixed-layer	Quartz	Smec	Vermiculite
70-100	-	-	-	-	-	-	very weak	-	-	-	-	-
100-115	-	very weak	-	-	-	-	very weak	-	-	-	-	-

Profile description

Ah1 0-7 cm	very dark greyish brown (10YR 3/2, moist)loam,strong fine subangular blocky,slightly hard friable non sticky non plastic,no cutans,common very fine continuous exped tubular vertical pores and common continuous exped interstitial vertical pores,no inclusions,no fragments,clear smooth boundary to,
Ah2 7-20 cm	dark brown (10YR 3/3, moist)loam,moderate fine subangular blocky and moderate fine angular blocky,slightly hard friable non sticky non plastic,no cutans,common very fine continuous exped and inped tubular vertical pores and common continuous exped and inped interstitial vertical pores,no inclusions,no fragments,gradual smooth boundary to,
Ah3 20-70 cm	dark brown (10YR 3/3, moist)sandy loam,weak medium angular blocky,soft very friable non sticky non plastic,no cutans,common very fine continuous exped and inped tubular random pores,no inclusions,no fragments,frequent coprogenic elements,clear smooth boundary to,
B 70-100 cm	(dark) brown (10YR 4/3, moist)loamy sand,weak medium angular blocky,loose very friable non sticky non plastic,few very fine continuous exped and inped tubular random pores,clear smooth boundary to,
C 100-115 cm	dark brown (10YR 3/3, moist)Description sand,structureless,loose loose non sticky non plastic,many fine continuous interstitial random pores highly porous (>60 vol%),clear smooth boundary to,
2B 115-140 cm	dark yellowish brown (10YR 4/4, moist)loamy sand,weak medium angular blocky,slightly hard 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	100cm
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	cultivated pasture
Remarks on Land Use / Vegetation	VEGETATION: Forest cut approximately in 1963
Rotation scheme ; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	crop rotation scheme not relevant

Altitude	250m
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	east
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	well
Flooding frequency (FAO, 1986)	never
Kind of ground water table (USDA, 1979)	no groundwater table observed
Moist From - To	0-130cm
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
Average size of stone	50
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
Shape of stones (on average)	(sub-)rounded
Surface stoniness class (FAO (2006) - Guidelines for soil description)	very few stones

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Reference soil Costa Rica 06: Andosol

Characteristics

Reference soil CR006: Andosols

Classification