Reference soil Costa Rica 09: Acrisol

CR009

Acrisols occur dominantly in the wetter parts of the tropics and subtropics and the warm temperate regions in relatively young landscapes.

Characteristics

Soils having an argic horizon (a subsurface horizon with distinct higher clay content than the overlying horizon), which has a cation exchange capacity of less than 24 cmolc per kg in some part, either starting within 100 cm from the soil surface, or within 200 cm from the soil surface if the argic horizon is overlain by loamy sand or coarser textures throughout. They have a base saturation (total amount of Ca, Mg, K and Na with respect to the cation exchange capacity) of less than 50 percent in the major part between 25 and 100 cm from the soil surface

Distribution of Acrisols (rough estimation supplied by soilgrids)

Reference soil CR009: Acrisols

Brief soil description: Very deep, well drained, brown clay soil, strongly acid and having a very low sum of exchangeable bases. In the lower part of the soil monolith cemented remains of the parent material can be observed. Cementing material is probably silica. Parent material is of fluvio-laharic origin. The original texture is not known with certainty, but appears to be andesitic sand. Topsoil (0-23) is severely compacted. Profile was described in extremely dry period. Therfore cracks were visible which normally don't occur. Actual classification: FAO (1988): Haplic Ferralsol USDA (1992): Andic Haploperox

Classification

WRB 2006

WRB 1998

Haplic- Acrisol (Alumic Humic Clayic)

Alumi-Humic- Acrisol

110-140 cm	cambic horizon
23-110 cm	argic horizon

0-8 cm	ochric horizon
110-140 cm	cambic horizon
23-110 cm	argic horizon
-	strongly humic

FAO-UNESCO-ISRIC 1988

FAO-UNESCO-ISRIC 1974

Humi-Haplic Acrisol

Orthic Ferralsol

0-8 cm	ochric A horizon
110-140 cm	cambic B horizon
23-110 cm	argic B horizon
-	strongly humic

0-8 cm	ochric A horizon
110-140 cm	cambic B horizon
8-110 cm	oxic B horizon

Local classification:	Suelo Neguev

Other classification

USDA-SCS (1975)

Haplorthox perudic clayey gibbsitic 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
0-8	0	0.2	0.5	1.5	3.4	3.1	8.7	6.2	30.8	37.0	54.3
0-23	0	0.3	0.7	1.6	4.3	2.4	9.3	5.7	23.2	28.9	61.8
23-110	0	0.3	0.5	1.2	3.1	2.4	7.5	5.6	21.5	27.1	65.5
110-140	0	1.3	1.9	3.9	12.8	6.9	26.8	15.6	36.1	51.7	21.5

Water retention characteristics

Depth (cm)	Bulk density kg/dm³	Spec. Surf. Area m²/g	COLE cm/cm	Water disp. clay %	Clay % w/w
0-8	-	-	-	7.7	54.3
0-23	-	-	-	12.7	61.8
23-110	-	-	-	10.7	65.5
110-140	-	-	-	11.0	21.5

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
0-8	4.5	4.3	0.74	-	3.96	0.47	8	0.6	0.2	3.2	3.1	0.9	0.0	7.2
0-23	4.6	4.3	0.24	-	2.74	0.34	8	0.8	0.2	1.5	1.4	0.2	0.1	3.2
23-110	4.6	4.2	0.02	-	0.73	0.10	7	1.6	1.2	0.0	0.1	0.1	0.0	0.2
110-140	4.8	4.9	0.02	-	0.26	0.04	7	0.1	0	0.0	0.1	0.0	0.1	0.2

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 %
0-8	39	18.3	34	13.9	-	1	0
0-23	23	13.9	22	9.6	-	1	1
23-110	2	8.2	13	2.6	-	15	0
110-140	3	6.0	28	0.9	-	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
0-8	-	-	-	0.53	0.04	-	-	-	-	-	1.25
0-23	-	-	-	0.54	0.01	-	-	-	-	-	0.93
23-110	-	-	-	0.61	0.03	-	-	-	-	-	0.62
110-140	-	-	-	0.72	0.07	-	-	-	-	-	0.88

Clay mineralogy

Depth (cm)	Chlorite	Feldspar	Gibbsite	Goethite	Halloysite	Hematite	Kaolinite	Mica / illite	Mixed-layer	Quartz	Smec	Vermiculite
0-8	-	-	strong	-	-	-	medium to strong	-	-	very weak	weak	-
0-23	-	-	strong	-	-	-	medium to strong	-	-	very weak	very weak	-
23-110	-	-	strong	-	-	-	medium to strong	-	-	-	very weak	-
110-140	-	-	strong	-	-	-	weak	-	-	-	very weak	-

Profile description

Ah 0-8 cm	very dark greyish brown (10YR 3/2, moist)silty clay,strong medium prismatic parting to moderate fine subangular blocky,very hard firm slightly sticky slightly plastic,common fine continuous exped interstitial vertical pores and common continuous exped and inped tubular random pores highly porous (>60 vol%),clear smooth boundary to,
Bw1 8-23 cm	(dark) brown (10YR 4/3, moist)silty clay,moderate medium prismatic parting to moderate medium angular blocky,hard friable slightly sticky slightly plastic,common fine continuous exped interstitial vertical pores and common continuous exped and inped tubular random pores,clear smooth boundary to,
Bw2 23-110 cm	dark yellowish brown (10YR 3/4, moist)silty clay,weak fine subangular blocky to weak porous massive,very friable slightly sticky slightly plastic,many very fine continuous exped and inped tubular random pores and many continuous exped and inped tubular random pores,
Bw3 110-140 cm	dark brown (10YR 3/3, moist)silty clay,weak fine subangular blocky to weak porous massive,very friable slightly sticky slightly plastic,many very fine continuous exped and inped tubular random pores and many continuous exped and inped tubular random pores highly porous (>60 vol%),

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	fluvio-laharic origin
Soil Depth	140cm
Texture of parent material	clayey
Weathering Resistance	poor
General characterization of the status of weathering of solid rock	highly

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: Deforested approximately in 1975
Rotation scheme ; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	crop rotation scheme not relevant

Altitude	30m
Physiographic Unit	flat top of dissected terrace
Physiographic position of the site	flat
Regional landform; McDonald, R.C., Isbell, R.F. et all, 1984; Australian soil and land survey Field Handbook, Inkata Press, Melbourne.	alluvial terrace
Slope	0%
Topography; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	flat or almost flat

Drainage class ; FAO (2006) - Guidelines for soil description	well
Dry From - To	0-25cm
Flooding frequency (FAO, 1986)	never
Kind of ground water table (USDA, 1979)	no groundwater table observed
Moist From - To	25-140cm
Estimated permeability (class) of least permeable part of the profile	high
Estimated run off (class)	very slow

Evidence of alkali ; Soil Survey Manual USDA, 1951	non-alkaline
Surface cracking	small cracks (width less than 1 cm, or depth less than 50 cm)
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 09: Acrisol

Characteristics

Reference soil CR009: Acrisols

Classification