Reference soil Kenya 18: Planosol

KE018

Distribution of Planosols

KE 18 is located on the slope of a termite mound, KE 17 is located on the active part on the mound and KE 19 in the plain, where no influence of the mound is noticeable. MICRO RELIEF: termite mounds of 1-2 m high and a diameter of 3-6 m occur at distances of 30-50 m. Vegetation/Land use: on the mounds shrubs, between the mounds grass, which is used for extensive grazing. Soil processes: KE 17, 18 and 19 are associated soils. Termites have throroughly mixed the different horizons as occuring in profile KE 19 which results in profile KE 17. KE 18 is a transition to KE 19. Additional notes on profile description: E: the clay cutans line pores and holes especially in the lower part of the horizon; Bt: E material is present along cracks; 85-105 cm: 90% gravel and stones, embedded in clay.

WRB 2006:

WRB 1998:

Luvic Planosol(Albic Hyposodic Clayic)

Luvi- Hyposodic Planosol(Albic)

28-45 cm	albic horizon
45-105 cm	argic horizon
abrupt textural change

FAO-UNESCO-ISRIC 1988:

FAO-UNESCO 1974:

Luvi-

Eutric Planosol

sodic phase

Solodic Planosol

0-28 cm	ochric A horizon
28-45 cm	albic E horizon
45-105 cm	argic B horizon
	abrupt textural change
	stagnic properties

0-28 cm	ochric A horizon
28-45 cm	albic E horizon
45-105 cm	argillic B horizon
	abrupt textural change
	hydromorphic properties

Other classification

USDA-NRCS (1999)

Typic

Albaqualf

USDA-SCS (1975)

Typic

Tropaqualf

fine

mixed

isohyperthermic

Location:

Nyanza Province, South Nyanza District, 10 km WSW of Rongo at Opapo

Parent material

The main parent rock/ material over which the soil has been formed (1st entry)	ejecta ash
Mode of Accumulation or deposition of parent material (1st entry)	fluvial
Texture of parent material (1st entry)	loamy
Weathering status of solid rock (1st entry)	highly
Resistance against weathering (solid rock) (1st entry)	poor
Depth1 of lithological boundary	cm
The main parent rock/ material over which the soil has been formed (2nd entry)	granite
Mode of Accumulation or deposition of parent material (2nd entry)	residual material
Texture of parent material (2nd entry)	gravelly
Resistance against weathering (solid rock) (2nd entry)
Soil Depth; depth to which roots can easily penetrate throughout the year	80 cm
Remarks on Parent Materials	termite mound underlain

Physical

Particle size distribution:

Depth (cm)		Gravel (%)	Very Coarse Sand (%)	Coarse Sand (%)	Medium Sand (%)	Fine Sand (%)	Very Fine Sand (%)	Total Sand (%)	Coarse Silt (%)	Total Silt (%)	Clay (%)
0-10	:	-	1.3	6.0	12.3	16.4	4.2	40.2	35.7	35.7	24.1
10-20	:	-	2.3	6.1	8.1	11.7	7.9	36.1	35.5	35.5	28.4
20-30	:	-	1.6	6.3	13.1	15.6	6.9	43.5	29.1	29.1	27.4
30-40	:	-	2.7	9.0	14.9	14.2	6.2	47	29.9	29.9	23.1
50-60	:	-	3.4	10.3	12.7	9.6	2.9	38.9	14.6	14.6	46.5
60-70	:	-	11.1	14.5	12.6	12.6	1.6	52.4	15.1	15.1	32.4

Other physical data

Depth (cm)		Bulk Density (kg/dm³)	Spec. Surf. Area (m2/g)	COLE (cm/cm)	Water Disp. Clay (%)	Clay (%)
0-10	:	-	-	-	7.9	24.1
10-20	:	-	-	-	6.9	28.4
20-30	:	-	-	-	9.9	27.4
30-40	:	-	-	-	14.8	23.1
50-60	:	-	-	-	17.8	46.5
60-70	:	-	-	-	16.9	32.4

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)
0-10	:	5.8	4.0	0.07	-	1.52	0.13	12	-	-	7.2	1.8	0.2	0.2	9.4
10-20	:	5.8	3.8	0.06	-	0.96	0.08	12	-	-	6.1	0.9	0.1	0.6	7.7
20-30	:	5.9	3.6	0.04	-	0.63	0.06	11	-	-	6.6	0.7	0.2	0.7	8.2
30-40	:	5.5	3.5	0.09	-	0.79	0.10	8	-	-	7.8	0.8	0.2	1.2	10
50-60	:	5.6	3.5	0.08	-	0.94	0.12	8	-	-	10.1	1.1	0.2	1.8	13.2
60-70	:	5.6	3.5	0.10	-	0.80	0.10	8	-	-	9.5	1.0	0.2	1.7	12.4

Depth (cm)		CEC Soil (cmol/kg)	CEC Clay (cmol/kg)	CEC Org (cmol/kg)	ECEC (cmol/kg)	Base sat. (%)	Al sat. (%)	ESP (%)
0-10	:	14.8	-	5.3	-	64	-	1
10-20	:	12.2	-	3.4	-	63	-	5
20-30	:	12.9	-	2.2	-	64	-	5
30-40	:	17.3	-	2.8	-	58	-	7
50-60	:	22.9	-	3.3	-	58	-	8
60-70	:	20.5	-	2.8	-	60	-	8

Elemental composition of the clay:

Depth (cm)		SiO2 (wt%)	Al2O3 (wt%)	Fe2O3 (wt%)	CaO (wt%)	MgO (wt%)	K2O (wt%)	Na2O (wt%)	TiO2 (wt%)
0-10	:	52.4	20.1	10.6	0.05	0.52	0.54	-	1.14
10-20	:	54.5	19.4	10.0	0.05	0.53	0.62	-	1.32
20-30	:	50.2	21.4	10.9	0.06	0.54	0.57	-	1.19
30-40	:	49.5	22.0	11.1	0.05	0.51	0.59	-	1.07
50-60	:	47.1	23.2	11.2	0.31	0.51	0.53	-	0.99
60-70	:	48.1	23.4	11.2	0.14	0.49	0.55	-	1.00

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)
0-10	:	0.11	0.23	11.0	96.69	4.4	13.1	3.3	3
10-20	:	0.11	0.24	10.5	97.27	4.8	14.5	3.6	3
20-30	:	0.03	0.15	11.0	96.04	4	12.2	3	3.1
30-40	:	0.02	0.14	11.4	96.38	3.8	11.9	2.9	3.1
50-60	:	0.02	0.10	12.7	96.66	3.4	11.2	2.6	3.2
60-70	:	0.02	0.12	12.2	97.22	3.5	11.4	2.7	3.3

Elemental composition of the soil:

Depth (cm)		SiO2 (wt%)	Al2O3 (wt%)	Fe2O3 (wt%)	CaO (wt%)	MgO (wt%)	K2O (wt%)	Na2O (wt%)	TiO2 (wt%)
0-10	:	81.5	6.3	3.4	0.37	0.18	0.53	-	0.55
10-20	:	82.9	5.9	3.2	0.33	0.16	0.58	-	0.59
20-30	:	82.4	7.1	3.8	0.30	0.16	0.54	-	0.60
30-40	:	80.5	8.7	4.7	0.32	0.17	0.50	-	0.58
50-60	:	72.9	11.0	5.8	0.36	0.24	0.47	-	0.63
60-70	:	76.1	10.0	5.4	0.31	0.20	0.39	-	0.54

Depth (cm)		MnO2 (wt%)	P2O5 (wt%)	LOI (wt%)	SiO2 / Al2O3 (mol/mol)	SiO2 / Fe2O3 (mol/mol)	SiO2 / R (mol/mol)	Al2O3 / Fe2O3 (mol/mol)
0-10	:	0.09	0.05	6.4	22	63.8	16.3	2.9
10-20	:	0.08	0.03	5.4	23.8	69.0	17.7	2.9
20-30	:	0.03	0.03	5.0	19.7	57.6	14.7	2.9
30-40	:	0.02	0.03	6.0	15.7	45.6	11.7	2.9
50-60	:	0.03	0.03	7.5	11.2	33.5	8.4	3.0
60-70	:	0.01	0.03	6.4	12.9	37.5	9.6	2.9

Clay mineralogy:

Depth (cm)		Kaolinite	Mica / illite	Vermiculite	Chlorite	Smec	Halloysite	Mixed layer	Quar	Feldspar	Gibbsite	Goethite	Hematite
0-10	:	weak	-	-	-	-	-	strong	very weak to weak	-	-	-	-
10-20	:	weak	-	-	-	-	-	strong	very weak to weak	-	-	-	-
20-30	:	weak	-	-	-	-	-	strong	very weak to weak	-	-	-	-
30-40	:	weak	-	-	-	-	-	strong	very weak to weak	-	-	-	-
50-60	:	weak	-	-	-	-	-	strong	very weak to weak	-	-	-	-
60-70	:	weak	-	-	-	-	-	strong	very weak to weak	-	-	-	-

Profile description:

Ah 0-28 cm	(10YR 6/1.5, dry) very dark greyish brown (10YR 3/2, moist), clay loam, weak very fine angular blocky, friable slightly sticky slightly plastic, few gravel fragments, non calcareous, clear wavy boundary to,
E 28-45 cm	(7.5YR 7/no, dry), clay loam, weak coarse prismatic to porous massive, friable non sticky non plastic, common (5-15%) medium distinct mottles (10YR 5/4), continuous thick clay cutans in root channels and pores, few gravel fragments, non calcareous, gradual smooth boundary to,
Bt1 45-85 cm	very dark greyish brown (10YR 3/2, moist), clay, moderate medium angular blocky, slightly sticky slightly plastic, common (5-15%) fine faint mottles (5YR 4/6), few gravel fragments, non calcareous, abrupt wavy boundary to,
2B 85-105 cm	gravelly clay, massive, dominant coarse gravel and stones (90% gravel), non calcareous,
2Bt2 105->105 cm	very dark greyish brown (10YR 3/2, moist), clay, moderate medium angular blocky, slightly sticky slightly plastic, common (5-15%) fine faint 5YR4/6 (yellowish red), few gravel fragments, non calcareous,

Current land use at the site	extensive grazing
Major crops
Main type of irrigation
Rotation scheme
Vegetation Type;The natural vegetation at the site	shrub
Status of vegetation
Remarks on Land Use / Vegetation	see remarks

The altitude of the soil profile relative to mean sea level, specified in meters	1340 m asl
Regional landform	plain
Topography of the surrounding country	flat or almost flat
Physiographic Unit in the immediate surrounding of the site	slope of termite mound
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	1 %
The physiographic position of the site where the profile is located	lower slope
Form of the slope surrounding the site
Slope Aspect of the site

Depth of groundwater table	cm
Groundwater Top	cm
Groundwater Bottom	cm
Kind of groundwater table	perched
Top Stagnating Layer	45 cm
Bottom Stagnating Layer	85 cm
Runoff	medium
Flooding frequency	never
Estimated permeablity (class) of least permeable part of the profile	slow
Drainage Class	imperfect
To Drainage Class	moderately well
Moisture conditions of the profile: dry from -to	0-45 cm
Moisture conditions of the profile: moist from -to	45-105 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	200
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

Soil erosion type (1st entry)
Occurrence of soil aggradation
Slope Stability

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Reference soil Kenya 18: Planosol