Reference soil Kenya 07: Ferralsol

KE007

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 KE007: Ferralsols

Ferralsol

Classification

WRB 2006

WRB 1998

Haplic- Ferralsol (Humic Dystric Clayic)

Hyperdystri-Humic- Ferralsol (Rhodic)

120-190 cm	ferralic horizon
19-120 cm	cambic horizon

FAO-UNESCO-ISRIC 1988

FAO-UNESCO-ISRIC 1974

Rhodi-Humic Ferralsol

Humic Ferralsol

0-19 cm	ochric A horizon
120-190 cm	ferralic B horizon
19-120 cm	cambic B horizon
-	strongly humic

0-19 cm	ochric A horizon
19-190 cm	oxic B horizon
-	high organic matter content in B horizon

Other classification

USDA-SCS (1975)

Haplohumox 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
0-19	-	0.1	0.5	2.4	4.8	2.8	10.6	3.9	13.8	17.7	71.6
19-43	-	0.0	0.5	1.9	4.3	2.3	9	0.4	4.6	5	85.9
43-60	-	0.1	0.4	1.6	3.7	2.3	8.1	3.0	5.1	8.1	83.9
60-75	-	0.0	0.5	1.4	3.5	2.3	7.7	2.8	5.7	8.5	83.8
75-120	-	0.1	0.4	1.1	2.9	2.1	6.6	0.4	6.2	6.6	87.6
120-150	-	0.1	0.3	1.1	2.7	2.0	6.2	2.0	5.4	7.4	86.4
150-190	-	0.0	0.0	0.1	0.2	0.2	0.5	3.1	8.1	11.2	88.3

Water retention characteristics

Depth (cm)	Bulk density kg/dm³	Spec. Surf. Area m²/g	COLE cm/cm	Water disp. clay %	Clay % w/w
13-18	1.07	-	-	-	-
0-19	-	108	-	31.5	71.6
56-61	0.92	-	-	-	-
19-43	-	101	-	26.8	85.9
138-143	0.98	-	-	-	-
43-60	-	100	-	17.6	83.9
60-75	-	101	-	19.0	83.8
75-120	-	102	-	15.0	87.6
120-150	-	102	-	3.5	86.4
150-190	-	105	-	0.5	88.3

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
13-18	1.07	54.1	53.9	46.4	35.5	33.1	31.7	27.1	25.7
56-61	0.92	59.9	58.0	51.1	37.0	30.7	26.4	23.3	21.9
138-143	0.98	58.8	57.5	53.5	43.5	35.5	29.7	25.7	24.4

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
0-19	6.1	5.0	0.09	-	2.31	0.15	15	1.4	1.5	4.9	4.3	1.4	0.0	10.6
19-43	5.3	4.1	0.04	-	1.31	0.09	15	2.5	2.9	1.9	1.2	0.8	0.0	3.9
43-60	4.7	4.0	0.04	-	1.20	0.08	15	2.0	2.3	1.2	0.4	0.4	0.0	2
60-75	4.7	4.0	0.03	-	1.12	0.08	14	2.0	2.4	1.4	0.7	0.4	0.0	2.5
75-120	4.9	4.1	0.02	-	0.96	-	-	2.0	2.4	1.2	0.4	0.2	0.0	1.8
120-150	4.8	4.1	0.02	-	0.80	-	-	2.2	2.2	1.0	0.3	0.1	0.0	1.4
150-190	4.8	4.1	0.02	-	0.68	-	-	2.4	2.4	1.2	0.3	0.2	0.0	1.7

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 %
0-19	50	21.0	29	8.1	-	7	0
19-43	21	18.6	22	4.6	-	16	0
43-60	12	16.4	20	4.2	-	14	0
60-75	16	15.5	18	3.9	-	15	0
75-120	12	15.1	17	3.4	-	16	0
120-150	9	14.9	17	2.8	-	15	0
150-190	11	15.4	17	2.4	-	16	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
0-19	-	-	-	0.26	0.04	3.21	0.36	-	-	-	0.18
19-43	-	-	-	0.31	0.04	3.29	0.47	-	-	-	0.17
43-60	-	-	-	0.32	0.03	3.40	0.50	-	-	-	0.16
60-75	-	-	-	0.31	0.03	3.40	0.59	-	-	-	0.16
75-120	-	-	-	0.32	0.04	3.52	0.49	-	-	-	0.17
120-150	-	-	-	0.32	0.04	3.49	0.44	-	-	-	0.18
150-190	-	-	-	0.35	0.04	3.58	0.49	-	-	-	0.20

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
60-75	42.6	32.6	8.4	0.02	0.12	0.35	0.09	1.40
75-120	42.2	32.1	8.6	0.03	0.12	0.33	0.06	1.51

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
60-75	0.05	0.09	13.8	99.52	2.2	13.5	1.9	6.1
75-120	0.05	0.09	13.8	98.89	2.2	13	1.9	5.8

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
0-19	27.7	0.20	5.2	0.53	0.20	0.14	45.4	1.57
19-43	29.6	0.06	4.9	0.45	0.14	0.11	44.5	1.57
43-60	30.4	0.03	5.3	0.41	0.11	0.10	45.3	1.51
60-75	29.4	0.04	5.4	0.41	0.12	0.09	45.7	1.61
75-120	30.7	0.02	5.4	0.39	0.11	0.08	44.5	1.63
120-150	30.8	0.02	5.5	0.36	0.11	0.07	44.5	1.55
150-190	31.2	0.02	5.8	0.35	0.12	0.04	43.1	1.59

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
0-19	8.3	15.0	0.15	0.10	2.8	23.2	2.5
19-43	9.5	14.0	0.07	0.08	2.6	24.2	2.3
43-60	9	14.0	0.06	0.07	2.5	22.7	2.3
60-75	8.5	13.8	0.08	0.07	2.6	22.5	2.4
75-120	8.9	14.1	0.06	0.07	2.5	21.9	2.2
120-150	8.8	13.7	0.06	0.07	2.5	21.5	2.2
150-190	8.4	13.8	0.06	0.06	2.3	19.8	2.1

Clay mineralogy

Depth (cm)	Chlorite	Feldspar	Gibbsite	Goethite	Halloysite	Hematite	Kaolinite	Mica / illite	Mixed-layer	Quartz	Smec	Vermiculite
0-19	-	-	-	weak	-	-	medium to strong	very weak	very weak to weak	-	-	-
19-43	-	-	-	weak	-	-	medium to strong	very weak	very weak to weak	-	-	-
43-60	-	-	-	weak	-	-	medium to strong	very weak	very weak to weak	-	-	-
60-75	-	-	-	weak	-	-	medium to strong	very weak	very weak to weak	-	-	-
75-120	-	-	-	weak	-	-	medium to strong	very weak	very weak to weak	-	-	-
120-150	-	-	-	weak	-	-	medium to strong	very weak	very weak to weak	-	-	-
150-190	-	-	-	weak	-	-	medium to strong	very weak	very weak to 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
75-120	3.2	12	96.8	96	-	88

Minerals

Depth (cm)	Anatase % w/w	Andalusite % w/w	Apatite % w/w	Augite % w/w	Biotite % w/w	Hornblende (basaltic) % w/w
75-120	-	-	-	-	-	1

Depth (cm)	Brookite % w/w	Chloritic % w/w	Disthene % w/w	Epidote % w/w	Garnet % w/w	Glaucophane % w/w
75-120	-	-	21	12	-	-

Depth (cm)	Grenate % w/w	Grossular % w/w	Muscovite % w/w	Rutile % w/w	Sillimanite % w/w	Spinel % w/w
75-120	1	-	-	14	3	-

Profile description

Ah 0-19 cm	dusky red (2.5YR 3/2, moist)clay,moderate medium subangular blocky to crumb,very friable sticky plastic,many fine roots,non calcareous,clear smooth boundary to,
Bo1 43-109 cm	dark reddish brown (2.5YR 3/4, moist)dark red (2.5YR 3/6, moist),clay,clay,weak medium subangular blocky,weak to moderate fine and medium subangular blocky,very friable slightly sticky slightly plastic,very friable sticky plastic,common very fine and fine pores,many very fine pores,few fine roots,many fine roots,non calcareous,non calcareous,gradual smooth boundary to,gradual smooth boundary to,
Bo2 109-149 cm	dark red (2.5YR 3/6, moist)clay,moderate medium and coarse angular blocky,friable slightly sticky slightly plastic,patchy thin clay cutans,many very fine and fine pores,few fine roots,non calcareous,

Kind 1 (parent material) ; Parker (eds), 1984	fine-grained intermediate igneous rock
Mode of accumulation or deposition of parent material	residual material
Remarks on Parent Materials	phonolite
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
Major vegetation type; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	deciduous shrub

Altitude	1325m
Physiographic Unit	volcanic plain, slightly to moderately dissected
Physiographic position of the site	slope
Regional landform; McDonald, R.C., Isbell, R.F. et all, 1984; Australian soil and land survey Field Handbook, Inkata Press, Melbourne.	plateau
Slope	3%
Topography; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	undulating

Drainage class ; FAO (2006) - Guidelines for soil description	well
Flooding frequency (FAO, 1986)	never
Depth to groundwater table	0cm
Kind of ground water table (USDA, 1979)	no groundwater table observed
(Estimated) minimum (upper) depth to groundwater table	0cm
Estimated permeability (class) of least permeable part of the profile	slow
Estimated run off (class)	medium

Evidence of alkali ; Soil Survey Manual USDA, 1951	non-alkaline
Slaking of aggregates by tillage, rainfall or frost (USDA/SCS, 1979)	no surface slaking/crusting observed
Microrelief Height: variation in height	0
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

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Reference soil Kenya 07: Ferralsol

Characteristics

Reference soil KE007: Ferralsols

Classification