Reference soil Kenya 06: Ferralsol

KE006

Ferralsols occur in tropical and subtropical regions of the world, mainly on old and stable land surfaces.

Characteristics

Soils having a ferralic horizon (strongly weathered horizon with low-activity clays and very low amounts of weatherable minerals) between 25 and 200 cm from the soil surface. They lack a nitic horizon (a horizon with strongly developed, nut-shaped structure) and do not have a layer which fulfils the requirements of an argic horizon and which has, in the upper 30 cm, 10 percent or more water-dispersible clay.

Distribution of Ferralsols (rough estimation supplied by soilgrids)

Reference soil KE006: Ferralsols

thin surface sealing, 3 mm thick

Classification

WRB 2006

WRB 1998

Mollic- Ferralsol (Humic Eutric Clayic)

Rhodi-Mollihumic- Ferralsol

0-32 cm	mollic horizon
60-190 cm	ferralic horizon

FAO-UNESCO-ISRIC 1988

FAO-UNESCO-ISRIC 1974

Rhodi-Humic Ferralsol

Rhodic Ferralsol

0-32 cm	mollic A horizon
60-190 cm	ferralic B horizon
-	strongly humic

0-32 cm	mollic A horizon
60-190 cm	oxic B horizon
-	high organic matter content in B horizon

Other classification

USDA-SCS (1975)

Eutrustox ustic clayey kaolinitic thermic

More images

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
0-16	-	0.3	1.6	8.6	16.7	6.7	33.9	4.1	7.7	11.8	54.3
16-32	-	0.2	1.0	7.2	15.7	6.1	30.2	4.8	4.4	9.2	60.7
32-60	-	0.2	0.9	6.2	15.9	6.1	29.3	4.7	3.8	8.5	62.2
60-90	-	0.3	0.9	5.1	14.3	6.2	26.8	4.4	4.5	8.9	64.2
90-120	-	0.1	0.9	4.3	12.7	6.3	24.3	4.4	4.5	8.9	66.8
120-160	-	0.4	0.9	3.5	11.1	6.3	22.2	5.5	4.9	10.4	67.5
160-190	-	0.4	0.8	3.0	9.8	6.1	20.1	6.3	5.2	11.5	68.4

Water retention characteristics

Depth (cm)	Bulk density kg/dm³	Spec. Surf. Area m²/g	COLE cm/cm	Water disp. clay %	Clay % w/w
8-13	1.00	91	-	-	-
0-16	-	91	-	17.1	54.3
16-32	-	91	-	20.0	60.7
85-90	1.04	89	-	-	-
170-175	1.04	94	-	-	-
32-60	-	89	-	16.3	62.2
60-90	-	89	-	4.5	64.2
90-120	-	93	-	1.5	66.8
120-160	-	92	-	4.0	67.5
160-190	-	94	-	2.0	68.4

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
8-13	1.00	55.5	55.2	43.6	29.6	26.5	24.4	20.6	16.3
85-90	1.04	55.4	53.4	46.6	35.7	26.9	20.7	19.9	-
170-175	1.04	55.9	55.9	50.5	39.1	33.0	28.7	24.0	22.9

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
0-16	5.6	4.8	0.10	-	2.59	0.13	20	0.1	0.0	6.2	2.2	0.7	0.0	9.1
16-32	5.3	4.5	0.08	-	1.67	0.10	17	0.1	0.2	10.1	1.4	0.5	0.0	12
32-60	5.3	4.8	0.06	-	1.04	0.07	15	0.1	0.2	3.5	1.1	0.4	0.0	5
60-90	5.2	5.0	0.06	-	0.74	0.04	19	0.0	0.2	2.9	0.7	0.3	0.0	3.9
90-120	4.8	4.6	0.05	-	0.64	0.05	13	0.1	0.2	2.7	0.7	0.2	0.0	3.6
120-160	5.1	5.1	0.05	-	0.54	0.03	18	0.0	0.2	2.5	1.0	0.3	0.0	3.8
160-190	5.2	5.2	0.05	-	0.52	0.03	17	0.0	0.2	2.7	1.2	0.2	0.0	4.1

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 %
0-16	57	15.9	29	9.1	-	0	0
16-32	94	12.8	21	5.8	-	2	0
32-60	59	8.5	14	3.6	-	2	0
60-90	53	7.4	12	2.6	-	3	0
90-120	49	7.4	11	2.2	-	3	0
120-160	51	7.4	11	1.9	-	3	0
160-190	53	7.7	11	1.8	-	3	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
0-16	-	-	-	0.26	0.10	4.60	0.32	0.09	0.10	-	0.25
16-32	-	-	-	0.30	0.10	4.89	0.35	0.10	0.19	-	0.30
32-60	-	-	-	0.29	0.10	4.90	0.36	0.05	0.13	-	0.29
60-90	-	-	-	0.31	0.10	5.15	0.41	0.02	0.09	-	0.28
90-120	-	-	-	0.30	0.10	5.44	0.45	0.02	0.09	-	0.31
120-160	-	-	-	0.30	0.10	5.63	0.44	0.01	0.08	-	0.32
160-190	-	-	-	0.28	0.10	5.47	0.44	0.01	0.07	-	0.33

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
60-90	37.2	34.0	13.3	0.03	0.13	0.31	-	1.24
120-160	38.4	34.7	13.9	0.03	0.14	0.29	-	1.31

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
60-90	0.09	0.11	13.9	100.31	1.9	7.4	1.5	4
120-160	0.07	0.09	13.7	102.63	1.9	7.3	1.5	3.9

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
0-16	18.6	0.26	8.2	0.55	0.16	-	59.4	1.02
16-32	20.6	0.17	8.6	0.51	0.14	-	57.9	1.04
32-60	21.5	0.13	9.0	0.49	0.11	-	57.9	1.07
60-90	22.8	0.12	9.6	0.48	0.14	-	55.9	1.13
90-120	23.4	0.09	9.9	0.48	0.12	-	55.3	1.16
120-160	24.1	0.10	10.3	0.47	0.13	-	53.3	1.20
160-190	25.1	0.09	10.7	0.46	0.13	-	52.8	1.22

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
0-16	3.6	11.3	0.14	0.10	5.4	19.3	4.2
16-32	3.8	10.5	0.12	0.08	4.8	17.9	3.8
32-60	3.7	9.8	0.09	0.08	4.6	17.1	3.6
60-90	3.7	9.7	0.09	0.05	4.2	15.5	3.3
90-120	3.7	10.0	0.08	0.05	4	14.9	3.2
120-160	3.7	10.1	0.07	0.05	3.8	13.8	2.9
160-190	3.7	10.5	0.08	0.05	3.6	13.1	2.8

Clay mineralogy

Depth (cm)	Chlorite	Feldspar	Gibbsite	Goethite	Halloysite	Hematite	Kaolinite	Mica / illite	Mixed-layer	Quartz	Smec	Vermiculite
0-16	-	-	weak to medium	weak	-	-	strong	-	weak	-	-	-
16-32	-	-	weak to medium	weak	-	-	strong	-	weak	-	-	-
32-60	-	-	weak to medium	weak	-	-	strong	-	weak	-	-	-
60-90	-	-	weak to medium	weak	-	-	strong	-	weak	-	-	-
90-120	-	-	weak to medium	weak	-	-	strong	-	weak	-	-	-
120-160	-	-	weak to medium	weak	-	-	strong	-	weak	-	-	-
160-190	-	-	weak to medium	weak	-	-	strong	-	weak	-	-	-

Sand mineralogy

Depth (cm)	Heavy Frac. sand % w/w	K-Feldspar % w/w	Light Fra. sand % w/w	Opaque % w/w	Plagioclase % w/w	Quartz % w/w
120-160	0.5	6	99.5	91	1	93

Minerals

Depth (cm)	Anatase % w/w	Andalusite % w/w	Apatite % w/w	Augite % w/w	Biotite % w/w	Hornblende (basaltic) % w/w
120-160	-	-	-	-	-	4

Depth (cm)	Brookite % w/w	Chloritic % w/w	Disthene % w/w	Epidote % w/w	Garnet % w/w	Glaucophane % w/w
120-160	-	-	1	9	-	-

Depth (cm)	Grenate % w/w	Grossular % w/w	Muscovite % w/w	Rutile % w/w	Sillimanite % w/w	Spinel % w/w
120-160	2	-	-	5	1	-

Profile description

Ah 0-32 cm	dusky red (2.5YR 3/2, moist)clay,weak to moderate very fine and fine subangular blocky,friable slightly sticky slightly plastic,common very fine and fine pores,many fine and common medium roots,non calcareous,clear smooth boundary to,
32-60 cm	dark red (2.5YR 3/6, moist)dark reddish brown (2.5YR 3/4, moist),clay,clay,moderate medium subangular blocky,moderate medium subangular blocky,friable sticky plastic,very friable slightly sticky slightly plastic,many very fine to medium pores,many very fine and fine pores,few fine roots,many fine and few medium roots,non calcareous,non calcareous,gradual smooth boundary to,gradual smooth boundary to,
Bo2 122-140 cm	dark red (2.5YR 3/6, moist)clay,weak fine subangular blocky,very friable slightly sticky slightly plastic,common very fine and fine pores,few fine roots,non calcareous,

Kind 1 (parent material) ; Parker (eds), 1984	gneiss
Mode of accumulation or deposition of parent material	residual material
Remarks on Parent Materials	Precambrian basement complex
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	semi-natural grassland, grazed
Remarks on Land Use / Vegetation	VEGETATION: Bushed wooded grassland
Rotation scheme ; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	crop rotation scheme not relevant
Major vegetation type; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	deciduous shrub

Altitude	1260m
Physiographic Unit	basement system
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.	pediplain
Slope	1%
Topography; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	flat or almost flat

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
Estimated permeability (class) of least permeable part of the profile	slow
Estimated run off (class)	slow

Evidence of alkali ; Soil Survey Manual USDA, 1951	non-alkaline
Slaking of aggregates by tillage, rainfall or frost (USDA/SCS, 1979)	surface slaked; sorted sand/silt, some clay films
Micro relief type: small-scale differences in relief in the direct vicinity of the site (FAO, 1986)	termite/ant mounds
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

You are here

Reference soil Kenya 06: Ferralsol

Characteristics

Reference soil KE006: Ferralsols

Classification