Reference soil Costa Rica 02: Umbrisol

CR002

Umbrisols occur mainly in regions where precipitation exceeds considerably the evapotranspiration. They are dominantly associated with acid parent materials.

Characteristics

Soils having an umbric horizon (deep, brownish or blackish surface horizon with a significant accumulation of organic matter and low base saturation). They have no diagnostic horizons other than an anthropedogenic horizon less than 50 cm thick, or an albic or cambic horizon.

Distribution of Umbrisols (rough estimation supplied by soilgrids)

Reference soil CR002: Umbrisols

A 'raised bed' technique was applied some years ago, with the result that about 30 cm soil was put on top of the original profile. At present the site is drained with drain ditches. Brief description of the soil: Very deep, moderately well to well drained, dark brown sandy clay soil. Stratification of alluvial deposits well visible thoughout the profile. The soil horizons (thickness and gravel content) varies at short distance. The four walls of the pit show different sequences. The wall from which the monliths were taken, was described. Other walls had higher gravel content. Actual classification FAO (1988): Umbric Cambisol

Classification

WRB 2006

WRB 1998

Cambic-Fluvic- Umbrisol (Humic Endoeutric Drainic)

Humic- Umbrisol

0-30 cm	umbric horizon
45-135 cm	cambic horizon
-	fluvic

0-30 cm	umbric horizon
45-135 cm	cambic horizon
-	fluvic
-	strongly humic

FAO-UNESCO-ISRIC 1988

FAO-UNESCO-ISRIC 1974

Fluvi-Humic Cambisol

Humic Cambisol

0-30 cm	umbric A horizon
45-135 cm	cambic B horizon
-	fluvic
-	strongly humic

0-30 cm	umbric A horizon
45-135 cm	cambic B horizon

Local classification:	Serie Instituto

Other classification

USDA-SCS (1975)

Eutropept udic loamy mixed 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
0-30	0	5.0	7.2	7.3	9.2	3.9	32.6	11.1	22.2	33.3	34.1
30-45	0	5.5	7.6	7.8	8.8	4.6	34.3	10.0	22.1	32.1	33.6
45-80	0	6.4	8.0	9.2	12.4	4.7	40.7	9.1	18.7	27.8	31.5
80-110	0	8.5	10.5	7.5	7.5	4.6	38.6	9.3	19.6	28.9	32.6
110-135	0	7.3	8.5	7.5	10.1	4.6	38	11.0	20.4	31.4	30.6
135-170	0	1.0	1.8	2.4	4.7	3.3	13.2	9.5	30.6	40.1	46.7

Water retention characteristics

Depth (cm)	Bulk density kg/dm³	Spec. Surf. Area m²/g	COLE cm/cm	Water disp. clay %	Clay % w/w
0-30	-	-	-	17.6	34.1
30-45	-	-	-	19.3	33.6
45-80	-	-	-	16.5	31.5
80-110	-	-	-	3.6	32.6
110-135	-	-	-	3.4	30.6
135-170	-	-	-	1.8	46.7

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
0-30	5.3	4.2	0.04	-	2.54	0.23	11	1.0	0.7	5.5	1.0	0.7	0.0	7.2
30-45	5.7	4.6	0.03	-	2.45	0.23	11	-	-	9.2	1.4	0.4	0.0	11.0
45-80	5.8	4.7	0.04	-	0.78	0.06	13	-	-	6.3	1.1	0.5	0.1	8.0
80-110	5.9	4.8	0.03	-	0.33	0.04	8	-	-	6.5	1.1	0.1	0.1	7.8
110-135	6.0	4.9	0.03	-	0.22	0.03	7	-	-	6.7	0.7	0.2	0.1	7.7
135-170	5.9	4.9	0.02	-	0.26	0.06	4	-	-	6.9	2.1	0.3	0.2	9.5

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 %
0-30	39	18.6	55	8.9	-	4	0
30-45	57	19.4	58	8.6	-	-	0
45-80	58	13.9	44	2.7	-	-	1
80-110	60	13.1	40	1.2	-	-	1
110-135	59	13.1	43	0.8	-	-	1
135-170	70	13.5	29	0.9	-	-	1

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
0-30	-	-	-	0.65	0.17	-	-	-	-	-	0.82
30-45	-	-	-	0.61	0.15	-	-	-	-	-	0.90
45-80	-	-	-	0.53	0.17	-	-	-	-	-	0.68
80-110	-	-	-	0.52	0.19	-	-	-	-	-	0.41
110-135	-	-	-	0.46	0.16	-	-	-	-	-	0.52
135-170	-	-	-	0.30	0.09	-	-	-	-	-	0.37

Clay mineralogy

Depth (cm)	Chlorite	Feldspar	Gibbsite	Goethite	Halloysite	Hematite	Kaolinite	Mica / illite	Mixed-layer	Quartz	Smec	Vermiculite
0-30	-	very weak	weak	weak	-	-	medium to strong	-	-	-	-	-
30-45	-	very weak	weak	weak	-	-	medium to strong	-	-	-	weak	-
45-80	-	very weak	weak	weak	-	-	medium to strong	-	-	-	weak	-
80-110	-	very weak	weak	weak	-	-	medium to strong	-	-	-	-	-
110-135	-	very weak	weak	weak	-	-	medium to strong	-	-	-	-	-
135-170	-	very weak	weak	weak	-	-	medium to strong	-	-	-	weak	-

Profile description

Ap 0-30 cm	dark brown (7.5YR 3/2, moist)sandy clay loam,moderate very fine subangular blocky,slightly hard very friable sticky slightly plastic,many very fine pores and few pores,clear smooth boundary to,
Ahb 30-45 cm	very dark brown (7.5YR 2/2, moist)sandy clay loam,strong fine subangular blocky,hard firm sticky slightly plastic,common very fine pores and few pores,clear smooth boundary to,
Bw1 45-80 cm	dark reddish brown (5YR 3/4, moist)sandy clay,moderate fine subangular blocky,hard friable sticky plastic,many very fine pores,gradual smooth boundary to,
Bw2 80-110 cm	(dark) brown (10YR 4/3, moist)sandy clay loam,moderate very fine subangular blocky,friable sticky slightly plastic,many very fine pores and few pores,gradual wavy boundary to,
Bg 110-135 cm	dark yellowish brown (10YR 4/4, moist)sandy clay,moderate fine subangular blocky,friable sticky slightly plastic,few medium distinct mottles,many very fine pores,abrupt smooth boundary to,
Cg 135-170 cm	dark yellowish brown (10YR 4/4, moist)clay,weak fine subangular blocky,friable sticky plastic,many medium clear mottles,many very fine pores,

Kind 1 (parent material) ; Parker (eds), 1984	sediment, unconsolidated
Mode of accumulation or deposition of parent material	fluvial
Remarks on Parent Materials	partly colluvial?
Soil Depth	150cm
Texture of parent material	sandy clay
Weathering Resistance	moderate
General characterization of the status of weathering of solid rock	slightly

Land improvements ; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	draining
Land use or vegetation in the immediate vicinity of the site	high level arable farming
Remarks on Land Use / Vegetation	LANDUSE: Experimental fields CATIE

Altitude	590m
Physiographic Unit	terrace of Reventazón river
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.	intermontane basin
Slope	1%
Topography; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	flat or almost flat

Drainage class ; FAO (2006) - Guidelines for soil description	moderately well
Dry From - To	0-80cm
Kind of ground water table (USDA, 1979)	no groundwater table observed
Moist From - To	80-170cm
Estimated permeability (class) of least permeable part of the profile	moderate
Estimated run off (class)	slow
Drainage class - intergrade; FAO (2006) - Guidelines for soil description	well

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 Costa Rica 02: Umbrisol

Characteristics

Reference soil CR002: Umbrisols

Classification