Reference soil Côte d'Ivoire 01: Acrisol

CI001

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 CI001: Acrisols

Extremely deep, somewhat excessively drained, red, very gravelly clay soil derived from Precambrian migmatites. The forest surface has a very thin, rapidly decomposing, litter layer and a what irregular surface. PARENT ROCK: Hard, rich in biotite, with a high mineralogical content of kaolinite, iron and aluminium (hydr-)oxides. Precambrian basement system. ADDITIONAL NOTES ON PROFILE DESCRIPTION: O - 3 to 4 types of leaves, various stages of decomposition; Gravel: concretions, ironstone; from 0-70cm angular; from 70cm+ spherical.

Classification

WRB 2006

WRB 1998

Pisoplinthic-Vetic- Acrisol (Hyperdystric Profondic Clayic)

Veti-Pisoplinthic- Acrisol (Profondic Hyperdystric)

0-100 cm	pisoplinthic horizon
50-160 cm	ferralic horizon
7-160 cm	argic horizon

FAO-UNESCO-ISRIC 1988

FAO-UNESCO-ISRIC 1974

Veti-Ferric Acrisol skeletic

Orthic Ferralsol petric

0-7 cm	ochric A horizon
50-160 cm	ferralic B horizon
7-160 cm	argic B horizon
-	ferric

0-7 cm	ochric A horizon
7-160 cm	oxic B horizon
-	ferric

Local classification:	Sol ferrallitique

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
0-7	76	4.9	2.9	17	29.2	12.7	66.7	8.5	5.3	13.8	19.4
7-20	75	3.0	1.8	11.6	22.6	11.2	50.2	9.5	6.9	16.4	33.4
20-45	77	3.5	2.5	7.5	12.5	7.6	33.6	9.3	7.0	16.3	50.1
50-70	75	4.8	1.5	4.0	6.6	4.4	21.3	6.4	7.5	13.9	64.8
80-100	71	5.4	1.6	3.9	6.4	4.2	21.5	5.8	10.2	16	62.5
115-135	8	1.3	1.1	3.9	6.3	4.2	16.8	9.9	16.0	25.9	57.2
135-150	7	0.9	0.6	3.3	5.7	4.3	14.8	9.5	18.3	27.8	57.5

Water retention characteristics

Depth (cm)	Bulk density kg/dm³	Spec. Surf. Area m²/g	COLE cm/cm	Water disp. clay %	Clay % w/w
0-7	-	-	-	5.3	19.4
120-135	1.37	75	-	-	-
7-20	-	-	-	14.5	33.4
20-45	-	-	-	27.2	50.1
50-70	-	-	-	0.5	64.8
80-100	-	-	-	0.5	62.5
115-135	-	-	-	0.0	57.2
135-150	-	-	-	0.0	57.5

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
120-135	1.37	48.7	47.4	44.3	41.3	40.0	38.8	33.6	33.0

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	5.9	4.8	0.16	-	3.11	0.16	19	0.1	0.0	5.3	1.0	0.1	0.0	6.4
7-20	4.9	3.8	0.05	-	1.32	0.01	132	1.2	1.1	0.8	0.5	0.0	0.1	1.4
20-45	4.4	3.6	0.03	-	1.05	0.02	53	2.9	2.7	0.0	0.2	0.0	0.1	0.3
50-70	4.6	3.7	0.02	-	0.68	0.07	10	2.9	2.4	0.0	0.2	0.0	0.0	0.2
80-100	4.7	3.8	0.02	-	0.40	-	-	2.1	2.0	0.0	0.1	0.0	0.0	0.1
115-135	4.6	3.8	0.02	-	0.26	-	-	2.2	2.0	0.0	0.1	0.0	0.2	0.3
135-150	4.7	3.8	0.02	-	0.21	-	-	2.3	2.3	0.0	0.0	0.0	0.0	-

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	72	8.9	46	10.9	-	0	0
7-20	27	5.1	15	4.6	-	22	2
20-45	5	5.9	12	3.7	-	46	2
50-70	4	5.3	8	2.4	-	45	0
80-100	3	3.9	6	1.4	-	51	0
115-135	8	3.9	7	0.9	-	51	5
135-150	-	3.5	6	0.7	-	66	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	-	-	-	0.07	0.01	2.66	0.36	-	-	-	0.23
7-20	-	-	-	0.09	0.01	3.67	0.57	-	-	-	0.36
20-45	-	-	-	0.11	0.01	4.37	0.79	-	-	-	0.22
50-70	-	-	-	0.12	0.02	5.53	0.92	-	-	-	0.18
80-100	-	-	-	0.12	0.02	5.30	0.82	-	-	-	0.18
115-135	-	-	-	0.09	0.02	5.21	0.69	7.29	0.87	-	0.13
135-150	-	-	-	0.10	0.03	5.44	0.74	-	-	-	0.13

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
0-7	38.1	32.6	12.9	0.05	0.20	0.17	-	1.64
7-20	38.4	33.5	13.6	0.00	0.15	0.13	-	1.64
20-45	36.7	33.4	14.3	0.00	0.15	0.10	-	1.58
50-70	36.5	33.6	14.6	0.01	0.13	0.08	-	1.53
80-100	37.0	33.9	14.8	0.00	0.11	0.06	-	1.56
115-135	36.4	33.9	14.8	0.00	0.12	0.09	-	1.60
135-150	37.8	33.6	14.9	0.00	0.10	0.10	-	1.63

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
0-7	0.05	0.40	14.0	100.11	2	7.8	1.6	4
7-20	0.03	0.34	13.4	101.19	1.9	7.5	1.5	3.9
20-45	0.03	0.26	23.7	110.22	1.9	6.8	1.5	3.7
50-70	0.04	0.22	13.6	100.31	1.8	6.6	1.4	3.6
80-100	0.04	0.23	13.7	101.4	1.9	6.6	1.4	3.6
115-135	0.04	0.22	13.8	100.97	1.8	6.5	1.4	3.6
135-150	0.04	0.23	13.7	102.1	1.9	6.7	1.5	3.5

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
0-7	7.2	0.22	7.7	0.04	0.08	-	75.9	0.78
7-20	11.8	0.01	8.6	0.05	0.08	-	70.1	1.05
20-45	18.1	0.00	11.5	0.06	0.10	-	60.0	1.36
50-70	23.3	0.00	14.2	0.05	0.09	-	49.2	1.5
80-100	23.8	0.00	13.9	0.05	0.11	-	49.4	1.44
115-135	26.0	0.00	12.5	0.08	0.10	-	48.3	1.47
135-150	25.9	0.00	11.9	0.09	0.10	-	49.4	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
0-7	1.5	8.3	0.03	0.06	17.9	26.2	10.6
7-20	2.2	7.5	0.02	0.05	10.1	21.7	6.9
20-45	2.5	9.5	0.03	0.07	5.6	13.9	4
50-70	2.6	11.1	0.03	0.08	3.6	9.2	2.6
80-100	2.7	10.7	0.03	0.06	3.5	9.4	2.6
115-135	3.3	10.9	0.03	0.05	3.2	10.3	2.4
135-150	3.4	10.9	0.03	0.06	3.2	11	2.5

Clay mineralogy

Depth (cm)	Chlorite	Feldspar	Gibbsite	Goethite	Halloysite	Hematite	Kaolinite	Mica / illite	Mixed-layer	Quartz	Smec	Vermiculite
0-7	weak	-	weak to medium	weak to medium	-	-	very strong	-	-	-	-	-
7-20	weak	-	weak to medium	weak to medium	-	-	very strong	-	-	-	-	-
20-45	weak	-	weak to medium	weak to medium	-	-	very strong	-	-	-	-	-
50-70	weak to medium	-	weak to medium	weak to medium	-	-	very strong	-	-	-	-	-
80-100	weak to medium	-	weak to medium	weak to medium	-	-	very strong	-	-	-	-	-
115-135	weak to medium	-	weak to medium	weak to medium	-	-	very strong	-	-	-	-	-
135-150	weak	-	weak to medium	weak to medium	-	-	very strong	-	-	-	-	-

Profile description

Ahoc 0-7 cm	dark brown (7.5YR 3/4, moist)very gravelly sandy loam,moderate fine and medium subangular blocky,friable slightly sticky slightly plastic,many very fine and fine interstitial and few micro fine tubular pores,many fine many coarse roots,dominant medium angular hard ferruginous concretions,very few medium gravel quartz fragments,non calcareous,clear smooth boundary to,
BAoc 7-20 cm	yellowish red (5YR 5/8, moist)very gravelly sandy clay loam,moderate fine and medium subangular blocky,friable sticky plastic,many very fine and fine interstitial and few micro to fine tubular pores,common fine common coarse roots,dominant medium angular hard ferruginous concretions,very few medium gravel quartz fragments,non calcareous,gradual smooth boundary to,
Boc1 20-45 cm	red (2.5YR 4/8, moist)very gravelly clay,moderate medium angular blocky,friable sticky plastic,pressure on rock fragments cutans,many very fine and fine interstitial pores and few micro and very fine tubular pores,few fine roots,dominant medium angular hard ferruginous concretions,very few medium gravel quartz fragments,non calcareous,diffuse smooth boundary to,
Boc2 45-115 cm	red (2.5YR 4/8, moist)very gravelly clay,moderate medium angular blocky,friable sticky plastic,pressure on rock fragments cutans,common very fine and fine interstitial pores and few micro and very fine tubular pores,few very fine roots,dominant medium spherical hard ferruginous concretions,very few medium gravel quartz fragments,non calcareous,gradual smooth boundary to,
Boc3 115-135 cm	red (2.5YR 4/6, moist)slightly gravelly clay,slightly gravelly clay,moderate very fine and fine angular blocky,moderate fine subangular blocky,friable sticky plastic,friable sticky plastic,pressure on rock fragments cutans,broken thin clay and sesquioxide cutans,common to many and very fine fine tubular pores,few very fine tubular pores,few very fine roots,few very fine roots,few medium spherical hard ferruginous concretions and few large spherical hard ferruginous concretions,very few medium spherical hard ferruginous concretions,non calcareous,non calcareous,clear smooth boundary to,

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

Land use or vegetation in the immediate vicinity of the site	nature and game preservation
Remarks on Land Use / Vegetation	Tropical 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	177m
Physiographic Unit	slope of dissected peneplain
Physiographic position of the site	upper slope
Regional landform; McDonald, R.C., Isbell, R.F. et all, 1984; Australian soil and land survey Field Handbook, Inkata Press, Melbourne.	peneplain
Slope	10%
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	somewhat excessive
Flooding frequency (FAO, 1986)	never
Kind of ground water table (USDA, 1979)	no groundwater table observed
Moist From - To	0-160cm
Estimated permeability (class) of least permeable part of the profile	moderate
Estimated run off (class)	medium

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
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 01: Acrisol

Characteristics

Reference soil CI001: Acrisols

Classification