Reference soil Côte d'Ivoire 02: Acrisol

CI002

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 CI002: Acrisols

PARENT ROCK: Hard migmatite, rich in biotite; Precambrian Basement System. ADDITIONAL NOTES ON PROFILE DESCRIPTION: O - 2 to 3 leaves thick (rapidly decomposing). Ahcs - nodules: with black patina. Bcs1 - color interior concretions: 5YR3/2; nodules: with black patina. Bcs2 - nodules: with black patina. 2Bws - color interior concretions: 2.5YR4/6. Gravel: iron concretions up to 5cm in diameter, irregular.

Classification

WRB 2006

WRB 1998

Pisoplinthic-Vetic- Acrisol (Hyperdystric Profondic Clayic)

Veti-Pisoplinthic- Acrisol (Profondic Hyperdystric)

0-70 cm	pisoplinthic horizon
10-150 cm	argic horizon
40-150 cm	ferralic horizon

FAO-UNESCO-ISRIC 1988

FAO-UNESCO-ISRIC 1974

Veti-Ferric Acrisol skeletic

Ferric Acrisol petric

0-10 cm	ochric A horizon
10-150 cm	argic B horizon
40-150 cm	ferralic B horizon
-	ferric

0-10 cm	ochric A horizon
10-150 cm	argillic B horizon
40-150 cm	oxic B horizon
-	ferric

Local classification:	Sol ferrallitique, see remarks

Other classification

USDA-NRCS (1999)	Typic Kandiudult
USDA-SCS (1975)	Typic Tropudult udic clayey-skeletal oxidic 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
0-10	75	8.5	3.4	17.2	27.0	12.4	68.5	8.9	5.2	14.1	17.0
10-30	71	12.1	4.2	10.0	21.3	10.1	57.7	9.0	4.7	13.7	28.6
40-70	63	6.8	2.8	6.0	10.3	5.8	31.7	9.3	6.0	15.3	52.8
80-100	5	3.8	3.0	5.0	9.1	5.5	26.4	12.2	15.6	27.8	45.8
110-150	2	2.0	1.5	4.1	8.5	5.0	21.1	13.0	17.2	30.2	48.7

Water retention characteristics

Depth (cm)	Bulk density kg/dm³	Spec. Surf. Area m²/g	COLE cm/cm	Water disp. clay %	Clay % w/w
0-10	-	-	-	2.4	17.0
10-30	-	-	-	13.4	28.6
40-70	-	-	-	0.5	52.8
80-100	1.49	-	-	0.5	45.8
110-150	-	-	-	0.0	48.7

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
80-100	1.49	45.2	43.7	40.7	37.7	36.4	34.9	32.1	30.2

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
0-10	5.6	4.2	0.14	-	3.45	0.22	16	0.4	0.2	3.3	1.3	0.2	0.3	5.1
10-30	4.7	3.8	0.06	-	1.08	0.09	12	1.4	1.1	0.2	0.3	0.1	0.2	0.8
40-70	4.6	3.8	0.03	-	0.79	0.06	13	2.0	1.8	0.0	0.1	0.0	0.2	0.3
80-100	4.6	3.8	0.03	-	0.43	0.04	11	2.1	1.8	0.0	0.1	0.0	0.2	0.3
110-150	4.5	3.7	0.03	-	0.22	-	-	2.3	1.8	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 %
0-10	53	9.6	56	12.1	-	2	3
10-30	15	5.4	19	3.8	-	20	-
40-70	6	5.1	10	2.8	-	35	4
80-100	6	5.1	11	1.5	-	35	4
110-150	4	4.8	10	0.8	-	38	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
0-10	-	-	-	0.08	0.01	3.50	0.31	-	-	-	0.23
10-30	-	-	-	0.14	0.02	3.72	0.42	-	-	-	0.37
40-70	-	-	-	0.18	0.03	5.69	0.70	-	1	-	0.22
80-100	-	-	-	0.15	0.02	6.14	0.65	-	1	-	0.15
110-150	-	-	-	0.17	0.03	5.87	0.53	-	-	-	0.14

Elemental composition of the clay

Depth (cm)	SiO2 % w/w	Al2O3 % w/w	Fe2O3 % w/w	CaO % w/w	MgO % w/w	K2O % w/w	Na2O % w/w	TiO2 % w/w
0-10	38.8	32.8	13.0	0.08	0.21	0.16	-	1.63
10-30	37.5	33.3	14.1	0.00	0.13	0.11	-	1.57
40-70	36.0	33.4	14.9	0.02	0.12	0.06	-	1.64
80-100	36.3	33.2	15.0	0.00	0.11	0.07	-	1.58
110-150	36.0	32.8	15.2	0.00	0.11	0.08	-	1.64

Depth (cm)	MnO2 % w/w	P2O5 % w/w	Ign.Loss clay % w/w	Total Clay % w/w	SiO2/Al2O3 mol/mol	SiO2/Fe2O3 mol/mol	SiO2 / R mol/mol	Al2O3/Fe2O3 mol/mol
0-10	0.07	0.36	14.1	101.21	2	7.9	1.6	4
10-30	0.03	0.29	13.9	100.93	1.9	7.1	1.5	3.7
40-70	0.03	0.18	13.9	100.25	1.8	6.4	1.4	3.5
80-100	0.03	0.23	13.8	100.32	1.9	6.4	1.4	3.5
110-150	0.03	0.18	13.9	99.94	1.9	6.3	1.4	3.4

Elemental composition of the soil

Depth (cm)	Al2O3 % w/w	CaO % w/w	Fe2O3 % w/w	K2O % w/w	MgO % w/w	Na2O % w/w	SiO2 % w/w	TiO2 % w/w
0-10	7.4	0.07	8.7	0.04	0.09	-	75.3	0.75
10-30	11.5	0.00	9.8	0.04	0.07	-	70.5	0.94
40-70	20.9	0.00	14.1	0.04	0.10	-	52.6	1.34
80-100	24.7	0.00	14.9	0.07	0.06	-	48.4	1.42
110-150	25.7	0.00	14.2	0.08	0.07	-	49.8	1.44

Depth (cm)	Al2O3/Fe2O3 mol/mol	LOI % w/w	MnO2 % w/w	P2O5 % w/w	SiO2 / Al2O3 mol/mol	SiO2/Fe2O3 mol/mol	SiO2 / R mol/mol
0-10	1.3	9.0	0.04	0.05	17.3	23.0	9.9
10-30	1.8	7.0	0.02	0.04	10.4	19.1	6.7
40-70	2.3	10.2	0.03	0.05	4.3	9.9	3
80-100	2.6	11.0	0.02	0.03	3.3	8.6	2.4
110-150	2.8	10.8	0.02	0.03	3.3	9.3	2.4

Clay mineralogy

Depth (cm)	Chlorite	Feldspar	Gibbsite	Goethite	Halloysite	Hematite	Kaolinite	Mica / illite	Mixed-layer	Quartz	Smec	Vermiculite
0-10	very weak to weak	-	weak	weak to medium	-	-	very strong	-	-	-	-	-
10-30	weak	-	weak	weak to medium	-	-	very strong	-	-	-	-	very weak
40-70	weak	-	weak	weak to medium	-	-	very strong	-	-	-	-	-
80-100	weak	-	weak	weak to medium	-	-	very strong	-	-	-	-	-
110-150	weak	-	very weak to weak	weak to medium	-	-	very strong	-	-	-	-	-

Profile description

Ahoc 0-10 cm	dark brown (7.5YR 3/4, moist)very gravelly sandy loam,weak fine subangular blocky,very friable slightly sticky slightly plastic,many micro to medium interstitial pores and many micro to medium tubular pores,many fine many coarse roots,frequent medium spherical hard ferruginous concretions and nodules,non calcareous,clear smooth boundary to,
Boc1 10-30 cm	yellowish red (5YR 5/6, moist)very gravelly sandy clay loam,moderate fine subangular blocky,friable sticky plastic,many micro to fine tubular common pores and common fine and medium interstitial pores,few fine roots,very frequent medium spherical hard ferruginous concretions and nodules,non calcareous,gradual smooth boundary to,
Boc2 30-80 cm	red (2.5YR 4/8, moist)very gravelly clay,moderate fine subangular blocky,friable sticky plastic,many very fine and fine tubular pores and many very fine and fine interstitial pores,few fine roots,very frequent medium spherical hard ferruginous concretions and nodules,non calcareous,diffuse smooth boundary to,
Bto 80-150 cm	red (2.5YR 4/6, moist)slightly gravelly clay,moderate fine angular blocky and moderate medium angular blocky,friable sticky plastic,few (2-5%) fine prominent clear mottles (10 YR 6/8),broken moderately thick clay and sesquioxide cutans around nodules,common very fine and fine interstitial common very fine and fine tubular pores,few fine roots,few medium angular hard ferruginous concretions and few medium angular hard argillaceous concretions,non calcareous,

Kind 1 (parent material) ; Parker (eds), 1984	metamorphic rock
Mode of accumulation or deposition of parent material	residual material
Remarks on Parent Materials	Precambriuan migmatite rich in biotite. saprolite
Texture of parent material	clayey
Weathering Resistance	moderate
General characterization of the status of weathering of solid rock	highly

Intensity of the soil erosion type	slight
Soil erosion type	sheet

Land use or vegetation in the immediate vicinity of the site	nature and game preservation
Remarks on Land Use / Vegetation	Tropical lowland forest, national park
Status of vegetation; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	primary
Major vegetation type; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	evergreen forest

Altitude	173m
Physiographic Unit	slope of dissected peneplain
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.	peneplain
Slope	5%
Slope Aspect	south-west
Form of the slope surrounding the site	convex
Topography; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	rolling

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	0-80cm
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	4
Surface cracking	no cracks observed
Slaking of aggregates by tillage, rainfall or frost (USDA/SCS, 1979)	no surface slaking/crusting observed
Microrelief Height: variation in height	60
Micro relief type: small-scale differences in relief in the direct vicinity of the site (FAO, 1986)	termite/ant mounds
Microrelief pattern	isolated
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 Côte d'Ivoire 02: Acrisol

Characteristics

Reference soil CI002: Acrisols

Classification