Reference soil Kenya 14: Phaeozem

KE014

Phaeozems occur all over the world, but especially on the more moist side of the steppe regions, bordering Chernozems.

Characteristics

Soils having a mollic horizon (deep, brownish or blackish surface horizon with a significant accumulation of organic matter and high base saturation); a base saturation of 50 percent or more between 25 and 100 cm from the soil surface; a calcium carbonate-free soil matrix at least to a depth of 100 cm from the soil surface, or to a contrasting layer between 25 and 100 cm; no diagnostic horizons other than an albic, argic, cambic or vertic horizon, or a petrocalcic horizon in the substratum.

Distribution of Phaeozems (rough estimation supplied by soilgrids)

Reference soil KE014: Phaeozems

A strongly calcareous, moderately well drained soil derived from fine-grained sandstones, with common moderate clay cutans below 30 cm and a weak surface sealing (5 mm); inactive termite mounds (5-10 m diameter, 1-2 m height) appear. (R3 pg 215)

Classification

WRB 2006

WRB 1998

Luvic- Phaeozem (Calcaric)

Calcari-Luvic- Phaeozem

0-30 cm	mollic horizon
30-110 cm	argic horizon
-	calcaric

FAO-UNESCO-ISRIC 1988

FAO-UNESCO-ISRIC 1974

Calcari-Luvic Phaeozem

Luvic Phaeozem

0-30 cm	mollic A horizon
30-110 cm	argic B horizon
-	calcareous

0-30 cm	mollic A horizon
30-110 cm	argillic B horizon

Other classification

USDA-NRCS (1999)	Typic Argiustoll
USDA-SCS (1975)	Typic Argiustoll ustic

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
0-30	-	0.2	0.3	0.4	8.1	37.4	46.4	24.9	8.8	33.7	19.9
30-50	-	0.6	0.4	0.3	0.6	28.4	30.3	17.6	7.1	24.7	45.1
50-84	-	2.1	2.1	2.1	6.8	24.2	37.3	21.8	11.0	32.8	30.0
84-110	10	-	-	-	-	-	-	-	-	-	-

Water retention characteristics

Depth (cm)	Bulk density kg/dm³	Spec. Surf. Area m²/g	COLE cm/cm	Water disp. clay %	Clay % w/w
33-38	1.44	-	-	-	-
0-30	-	-	-	4.5	19.9
30-50	-	-	-	10.8	45.1
55-60	1.56	-	-	-	-
50-84	-	-	-	8.5	30.0

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
33-38	1.44	40.8	40.8	39.4	35.2	32.6	29.4	21.7	19.6
55-60	1.56	40.3	40.0	40.3	37.6	35.7	33.3	18.7	16.7

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
0-30	6.7	5.6	0.61	0.8	1.08	0.08	14	-	-	6.5	2.9	1.2	0.0	10.6
30-50	6.7	5.3	0.22	0.5	0.52	0.05	10	-	-	8.2	7.2	0.7	0.1	16.2
50-84	7.9	6.9	0.29	0.32	0.32	0.04	8	-	-	14.4	7.8	0.4	0.1	22.7
84-110	8.1	6.8	0.10	-	-	-	-	-	-	-	-	-	-	-

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 %
0-30	100	10.6	53	3.8	-	-	0
30-50	99	16.4	36	1.8	-	-	1
50-84	132	17.2	57	1.1	-	-	1
84-110	-	15.6	-	-	-	-	-

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
0-30	-	-	-	0.08	0.00	0.84	0.13	0.10	0.16	-	0.10
30-50	-	-	-	0.15	-	1.85	0.27	0.11	0.29	-	0.14
50-84	-	-	-	0.08	0.05	1.42	0.20	0.07	0.17	-	0.08
84-110	-	-	-	0.04	-	1.07	0.13	0.02	0.03	-	0.04

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
0-30	11.0	0.41	2.8	1.91	0.56	-	76.1	0.56
30-50	17.0	0.38	5.1	1.73	0.90	-	67.5	0.68
50-84	16.5	1.15	5.3	1.99	1.73	-	66.7	0.75
84-110	14.1	4.10	5.0	1.92	2.41	-	62.3	0.73

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
0-30	6.2	6.3	0.06	0.07	11.7	72.4	10.1
30-50	5.2	5.5	0.04	0.03	6.7	35.2	5.7
50-84	4.9	5.9	0.12	0.04	6.9	33.5	5.7
84-110	4.4	4.2	0.12	0.09	7.5	33.1	6.1

Clay mineralogy

Depth (cm)	Chlorite	Feldspar	Gibbsite	Goethite	Halloysite	Hematite	Kaolinite	Mica / illite	Mixed-layer	Quartz	Smec	Vermiculite
0-30	-	-	-	weak to medium	-	-	medium to strong	weak	weak to medium	very weak to weak	-	-
30-50	-	-	-	weak to medium	-	-	weak to medium	weak	weak to medium	very weak	-	-
50-84	-	-	-	weak to medium	-	-	weak to medium	very weak to weak	strong	very weak	-	-
84-110	-	-	-	weak	-	-	weak to medium	very weak to weak	strong	very weak	-	-

Profile description

Ap 0-30 cm	dark brown (10YR 3/3, moist)loam,weak fine and medium angular blocky,slightly hard firm slightly sticky slightly plastic,slightly calcareous (0-2%),clear smooth boundary to,
Btk1 30-50 cm	yellowish brown (10YR 5/4, moist)clay loam,moderate medium and coarse angular blocky,hard firm sticky plastic,broken moderately thick clay cutans,common fine medium pores,calcareous concretions,slightly calcareous (0-2%),clear smooth boundary to,
Btk2 50-110 cm	yellowish brown (10YR 5/4, moist)clay loam,moderate medium and coarse angular blocky,hard firm sticky plastic,calcareous concretions,moderately calcareous (2-10%),abrupt smooth boundary to,
C 110-110 cm	massivemoderately calcareous (2-10%),

Kind 1 (parent material) ; Parker (eds), 1984	sandstone
Mode of accumulation or deposition of parent material	residual material
Remarks on Parent Materials	Mariakani sandstones (fine-grained)
Texture of parent material	loamy
Weathering Resistance	moderate
General characterization of the status of weathering of solid rock	partially or moderately

Major crops	maize
Land use or vegetation in the immediate vicinity of the site	arable farming

Altitude	170m
Physiographic Unit	coastal uplands
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.	plain
Slope	5%
Topography; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	undulating

Drainage class ; FAO (2006) - Guidelines for soil description	moderately well
Flooding frequency (FAO, 1986)	never
Depth to groundwater table	0cm
(Estimated) minimum (upper) depth to groundwater table	0cm
Estimated permeability (class) of least permeable part of the profile	moderate
Estimated run off (class)	medium

Evidence of alkali ; Soil Survey Manual USDA, 1951	slightly alkaline
Slaking of aggregates by tillage, rainfall or frost (USDA/SCS, 1979)	surface partly slaked, round smooth aggregates
Microrelief Height: variation in height	200
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 Kenya 14: Phaeozem

Characteristics

Reference soil KE014: Phaeozems

Classification