Reference soil Côte d'Ivoire 1: Acrisol

CI001

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+ sphericalReference soil

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 1974:

Veti-

Ferric Acrisol

skeletic phase

Orthic Ferralsol

petric phase

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

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

Location:

Tai Forest Reserve, parcelle de Fred Vooren, layon LS2, near hill top

Study of the iron forms occurring in the soils of a typical migmatite catena in the Taï region, south-west Côte d'Ivoire

Physical

Depth (cm)		Gravel (%)	Very Coarse Sand (%)	Coarse Sand (%)	Medium Sand (%)	Fine Sand (%)	Very Fine Sand (%)	Total Sand (%)	Coarse Silt (%)	Fine Silt (%)	Total Silt (%)	Clay (%)
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)	pF 0 (% w/v)	pF 1.0 (% w/v)	pF 1.5 (% w/v)	pF 2.0 (% w/v)	pF 2.3 (% w/v)	pF 2.7 (% w/v)	pF 3.4 (% w/v)	pF 4.2 (% w/v)	pF 2.5 (%)
120-135	:	1.37	48.7	47.4	44.3	41.3	40.0	38.8	33.6	33.0	-

Other physical data

Depth (cm)		Bulk Density (kg/dm³)	Spec. Surf. Area (m2/g)	COLE (cm/cm)	Water Disp. Clay (%)	Clay (%)
0-7	:	-	-	-	5.3	19.4
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

Chemical characteristics:

Depth (cm)		pH H2O	pH KCl	EC 1 : 2.5 (mS/cm)	CaCO3 (%)	Org. C (%)	Org. N (%)	C / N	Exch. Acid (cmol/kg)	Exch. Al (cmol/kg)	Ca (cmol/kg)	Mg (cmol/kg)	K (cmol/kg)	Na (cmol/kg)	Sum Cations (cmol/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)		CEC Soil (cmol/kg)	CEC Clay (cmol/kg)	CEC Org (cmol/kg)	ECEC (cmol/kg)	Base sat. (%)	Al sat. (%)	ESP (%)
0-7	:	8.9	-	10.9	-	72	-	0
7-20	:	5.1	-	4.6	-	27	-	2
20-45	:	5.9	-	3.7	-	5	-	2
50-70	:	5.3	-	2.4	-	4	-	0
80-100	:	3.9	-	1.4	-	3	-	0
115-135	:	3.9	-	0.9	-	8	-	5
135-150	:	3.5	-	0.7	-	-	-	0

Depth (cm)		pH NaF	P Retention (%)	ODOE	Melanic Index	Fe o (wt%)	Al o (wt%)	Si o (wt%)	Fe d (wt%)	Al d (wt%)	Fe p (wt%)	Al p (wt%)	C p (wt%)
0-7	:	-	-	-	-	0.23	0.07	0.01	2.66	0.36	-	-	-
7-20	:	-	-	-	-	0.36	0.09	0.01	3.67	0.57	-	-	-
20-45	:	-	-	-	-	0.22	0.11	0.01	4.37	0.79	-	-	-
50-70	:	-	-	-	-	0.18	0.12	0.02	5.53	0.92	-	-	-
80-100	:	-	-	-	-	0.18	0.12	0.02	5.30	0.82	-	-	-
115-135	:	-	-	-	-	0.13	0.09	0.02	5.21	0.69	7.29	0.87	-
135-150	:	-	-	-	-	0.13	0.10	0.03	5.44	0.74	-	-	-

Elemental composition of the clay:

Depth (cm)		SiO2 (wt%)	Al2O3 (wt%)	Fe2O3 (wt%)	CaO (wt%)	MgO (wt%)	K2O (wt%)	Na2O (wt%)	TiO2 (wt%)
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

Elemental composition of the clay:

Depth (cm)		MnO2 (wt%)	P2O5 (wt%)	Ign.Loss clay (wt%)	Total clay (%)	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)		SiO2 (wt%)	Al2O3 (wt%)	Fe2O3 (wt%)	CaO (wt%)	MgO (wt%)	K2O (wt%)	Na2O (wt%)	TiO2 (wt%)
0-7	:	75.9	7.2	7.7	0.22	0.08	0.04	-	0.78
7-20	:	70.1	11.8	8.6	0.01	0.08	0.05	-	1.05
20-45	:	60.0	18.1	11.5	0.00	0.10	0.06	-	1.36
50-70	:	49.2	23.3	14.2	0.00	0.09	0.05	-	1.5
80-100	:	49.4	23.8	13.9	0.00	0.11	0.05	-	1.44
115-135	:	48.3	26.0	12.5	0.00	0.10	0.08	-	1.47
135-150	:	49.4	25.9	11.9	0.00	0.10	0.09	-	1.44

Elemental composition of the soil:

Depth (cm)		MnO2 (wt%)	P2O5 (wt%)	LOI (wt%)	SiO2 / Al2O3 (mol/mol)	SiO2 / Fe2O3 (mol/mol)	SiO2 / R (mol/mol)	Al2O3 / Fe2O3 (mol/mol)
0-7	:	0.03	0.06	8.3	17.9	26.2	10.6	1.5
7-20	:	0.02	0.05	7.5	10.1	21.7	6.9	2.2
20-45	:	0.03	0.07	9.5	5.6	13.9	4	2.5
50-70	:	0.03	0.08	11.1	3.6	9.2	2.6	2.6
80-100	:	0.03	0.06	10.7	3.5	9.4	2.6	2.7
115-135	:	0.03	0.05	10.9	3.2	10.3	2.4	3.3
135-150	:	0.03	0.06	10.9	3.2	11	2.5	3.4

Clay mineralogy:

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

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, moderate fine subangular blocky, friable sticky plastic, pressure on rock fragments cutans, common to many and very fine fine tubular pores, few very fine roots, few medium spherical hard ferruginous concretions and few large spherical hard ferruginous concretions, non calcareous, clear smooth boundary to,
2Bto 135-160 cm	slightly gravelly clay, moderate very fine and fine angular blocky, friable sticky plastic, broken thin clay and sesquioxide cutans, few very fine tubular pores, few very fine roots, very few medium spherical hard ferruginous concretions, non calcareous,

The main parent rock/ material over which the soil has been formed (1st entry)	metamorphic rock
Mode of Accumulation or deposition of parent material (1st entry)	residual material
Texture of parent material (1st entry)	clayey
Weathering status of solid rock (1st entry)	highly
Resistance against weathering (solid rock) (1st entry)	moderate
Depth1 of lithological boundary	cm
The main parent rock/ material over which the soil has been formed (2nd entry)
Resistance against weathering (solid rock) (2nd entry)
Soil Depth; depth to which roots can easily penetrate throughout the year	cm
Remarks on Parent Materials	Precambrian migmatite rich in biotite

Current land use at the site	nature and game preservation
Major crops
Main type of irrigation
Rotation scheme
Vegetation Type;The natural vegetation at the site	evergreen forest
Status of vegetation	primary
Remarks on Land Use / Vegetation	Tropical forest, national park

The altitude of the soil profile relative to mean sea level, specified in meters	177 m asl
Regional landform	peneplain
Topography of the surrounding country	rolling
Physiographic Unit in the immediate surrounding of the site	slope of dissected peneplain
The slope refers to the inclination of the land immediately surrounding the site. The measured or estimated slope angle is specified to the nearest per cent	10 %
The physiographic position of the site where the profile is located	upper slope
Form of the slope surrounding the site	convex
Slope Aspect of the site	south-west

Depth of groundwater table	cm
Groundwater Top	cm
Groundwater Bottom	cm
Kind of groundwater table	no groundwater table observed
Top Stagnating Layer	cm
Bottom Stagnating Layer	cm
Runoff	medium
Flooding frequency	never
Estimated permeablity (class) of least permeable part of the profile	moderate
Drainage Class	somewhat excessive
To Drainage Class
Moisture conditions of the profile: dry from -to	cm
Moisture conditions of the profile: moist from -to	0-160 cm
Wet From - To	cm

Microrelief type: small-scale differences in relief in the direct vicinity of the site		termite/ant mounds
Microrelief Pattern		isolated
Microrelief Height		60
Rockiness		none
Stoniness		none
Average size of stones
Shape of stones (on average)
Cracks		no cracks observed
Slaking of aggregates by tillage, rainfall or frost		no surface slaking/crusting observed
Evidence of salt		non-saline
Evidence of alkali		non-alkaline

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Reference soil Côte d'Ivoire 1: Acrisol