Reference soil Kenya 45: Ferralsol

KE045

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 KE045: Ferralsols

Augerhole: 260 - 370. The topsoil is eroded. Slides: 10,052 -10,053 and 10,060 -10,063.

Classification

WRB 2006

WRB 1998

Haplic- Ferralsol (Eutric Clayic Rhodic)

Rhodic- Ferralsol

130-250 cm	ferralic horizon
35-250 cm	ferralic horizon

FAO-UNESCO-ISRIC 1988

FAO-UNESCO-ISRIC 1974

Orthi-Rhodic Ferralsol

Rhodic Ferralsol

0-35 cm	ochric A horizon
35-250 cm	ferralic B horizon

0-35 cm	ochric A horizon
35-250 cm	oxic B horizon

Other classification

USDA-NRCS (1999)	Rhodic Eutrustox
USDA-SCS (1975)	Rhodic Eutrorthox ustic very fine isothermic

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
0-35	-	0.4	0.3	0.6	1.2	0.8	3.3	0.8	8.6	9.4	87.4
35-80	-	0.2	0.3	0.4	0.8	0.6	2.3	0.5	6.5	7	90.8
80-130	-	0.4	0.3	0.5	0.9	0.7	2.8	0.5	9.1	9.6	87.7
130-160	-	3.0	4.0	2.7	2.1	1.0	12.8	3.4	14.3	17.7	69.3

Water retention characteristics

Depth (cm)	Bulk density kg/dm³	Spec. Surf. Area m²/g	COLE cm/cm	Water disp. clay %	Clay % w/w
0-35	-	-	-	25.9	87.4
35-80	-	-	-	10.9	90.8
80-130	-	-	-	0.5	87.7
130-160	-	-	-	-	69.3

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
0-35	5.6	4.8	0.08	-	1.56	0.20	8	0.3	0.0	6.4	3.1	1.2	0.0	10.7
35-80	5.3	4.6	0.05	-	0.76	0.15	5	0.2	0.0	3.9	2.7	0.6	0.0	7.2
80-130	5.1	4.4	0.03	-	0.51	0.10	5	0.1	0.0	3.9	3.3	0.1	0.0	7.3
130-160	4.8	4.0	0.02	-	0.31	0.06	5	0.5	0.2	1.9	1.6	0.1	0.0	3.6

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 %
0-35	82	13.0	15	5.5	-	0	0
35-80	65	11.0	12	2.7	-	0	0
80-130	82	8.9	10	1.8	-	0	0
130-160	47	7.6	11	1.1	-	5	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
0-35	-	-	-	0.3	0.1	5.0	0.5	-	-	-	0.3
35-80	-	-	-	0.3	0.1	5.1	0.4	-	-	-	0.3
80-130	-	-	-	0.2	0.1	5.1	0.5	-	-	-	0.2
130-160	-	-	-	0.2	0.1	7.8	0.9	-	-	-	0.2

Clay mineralogy

Depth (cm)	Chlorite	Feldspar	Gibbsite	Goethite	Halloysite	Hematite	Kaolinite	Mica / illite	Mixed-layer	Quartz	Smec	Vermiculite
0-35	-	-	-	weak	-	-	strong	-	very weak to weak	-	-	-
35-80	-	-	-	weak	-	-	strong	-	very weak to weak	-	-	-
80-130	-	-	-	weak	-	-	strong	-	very weak to weak	very weak	-	-
130-160	-	-	-	weak	-	-	strong	-	very weak to weak	weak	-	-

Profile description

Ah 0-35 cm	dark reddish brown (5YR 3/4, dry) dark reddish brown (2.5YR 3/4, moist)silty clay,moderate fine crumb and moderate fine subangular blocky,hard very friable slightly sticky slightly plastic,continuous thin clay cutans,many very fine pores and common fine pores,many very fine roots,non calcareous,gradual smooth boundary to,
Bt 35-130 cm	dark reddish brown (2.5YR 3/4, dry) dark reddish brown (2.5YR 3/4, moist)silty clay,weak angular blocky parting to strong medium subangular blocky,slightly hard very friable slightly sticky slightly plastic,broken moderately thick clay cutans,common very fine and few fine pores,common very fine roots,non calcareous,abrupt smooth boundary to,
2Btoc 130-250 cm	dark red (2.5YR 3/6, dry) dark red (2.5YR 3/6, moist)very gravelly silty clay,weak medium subangular blocky,soft very friable slightly sticky slightly plastic,patchy thin clay cutans,common very fine and few fine pores,dominant medium spherical hard ferruginous concretions,non calcareous,abrupt smooth boundary to,
Auger 250-300 cm	dark yellowish brown (10YR 4/6, moist)silty clay,many (15-40%) coarse faint diffuse mottles (10 YR 5/8),non calcareous,abrupt smooth boundary to,
Auger 300-350 cm	yellowish brown (10YR 5/4, moist)silty clay,non calcareous,abrupt smooth boundary to,
C3 350-370 cm	yellowish brown (10YR 5/8, moist)silty clay,many (15-40%) coarse faint diffuse mottles (10 YR 4/6),non calcareous,

Kind 1 (parent material) ; Parker (eds), 1984	basic volcanic breccia
Kind 2 (parent material) (second entry); Parker (eds), 1984	basic volcanic breccia
Mode of accumulation or deposition of parent material	colluvial
Mode of accumulation or deposition of parent material (second entry)	residual material
Remarks on Parent Materials	phonolite/lahar
Soil Depth	80cm
Texture of parent material	clayey
Texture of parent material (second entry)	clayey
Weathering Resistance	poor
Weathering Resistance (second entry)	moderate
General characterization of the status of weathering of solid rock	highly
General characterization of the status of weathering of solid rock (second entry)	highly

Occurrence of soil aggradation (McDonald et al., 1984)	absent
Intensity of the soil erosion type	slight
Intensity of the soil erosion type (second entry)	slight
Soil erosion type	sheet
Soil erosion type (second entry)	rill
Slope stability	stable

Major crops	coffee
Land improvements ; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	terracing
Main type of irrigation; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	no irrigation
Land use or vegetation in the immediate vicinity of the site	medium level arable farming
Remarks on Land Use / Vegetation	LAND USE: Pasture/grazing around the pit
Rotation scheme ; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	crop rotation scheme not relevant

Altitude	1380m
Physiographic Unit	minor valley, mount. footridge
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.	plateau
Slope	10%
Form of the slope surrounding the site	straight
Topography; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	hilly

Drainage class ; FAO (2006) - Guidelines for soil description	well
Dry From - To	0-250cm
Flooding frequency (FAO, 1986)	never
Kind of ground water table (USDA, 1979)	no groundwater table observed
Moist From - To	250-370cm
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 pattern	none
Rock outcrop class (FAO (2006) - Guidelines for soil description)	little rocky
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 45: Ferralsol

Characteristics

Reference soil KE045: Ferralsols

Classification