Reference soil Kenya 03: Planosol

KE003

Planosols occur in level landscapes throughout the world often associated with broad river valleys.

Characteristics

Soils having an eluvial horizon, the lower boundary of which is marked. within 100 cm from the soil surface, by an abrupt textural change associated with stagnic properties above that boundary. The feature of albeluvic tonguing, however, is lacking.

Distribution of Planosols (rough estimation supplied by soilgrids)

Reference soil KE003: Planosols

a dark-coloured (10 YR 4/2 dark greyish brown to 10 YR 3/1 very dark grey) soil of volcanic ejecta with many very fine pores in 2 upper horizons, but all in all poorly drained, with a texture changing from silty clay loam to clay in the 4th horizon. The Bcs consists of up to 50 % of ferro-manganese concretions sized 2 to 10 mm and has few clay cutans which increase rapidly with depth.

Classification

WRB 2014

Planosol

FAO-UNESCO-ISRIC 1988

FAO-UNESCO-ISRIC 1974

Eutric Planosol sodic

Solodic Planosol

- cm	albic E horizon
- cm	ochric A horizon

Other classification

USDA-NRCS (1999)	Albaqualf
USDA-SCS (1975)	Albaqualf aquic

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
0-15	-	0.3	0.3	0.3	0.8	2.1	3.8	12.2	51.1	63.3	33
15-26	-	0.3	0.3	0.7	1.5	1.7	4.5	7.3	49.7	57	38.4
26-38	-	0.4	1.6	3.9	5.7	3.4	15.0	15.7	37.9	53.6	31.3
49-65	-	1.2	1.6	1.6	1.9	1.2	7.5	0.6	14.7	15.3	77.3
80-80	-	0.4	0.6	1.6	1.2	0.7	4.5	0.6	11.3	11.9	84.2
100-100	-	0.6	0.7	0.7	1.1	0.7	3.8	0.6	19.2	19.8	76.5
115-115	-	0.5	0.6	0.8	1.2	0.8	3.9	0.8	10.8	11.6	84.6

Water retention characteristics

Depth (cm)	Bulk density kg/dm³	Spec. Surf. Area m²/g	COLE cm/cm	Water disp. clay %	Clay % w/w
0-15	-	-	-	-	33
15-26	-	-	-	-	38.4
26-38	-	-	-	-	31.3
49-65	-	-	-	-	77.3
80-80	-	-	-	-	84.2
100-100	-	-	-	-	76.5
115-115	-	-	-	-	84.6

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
0-15	5.9	4.7	0.22	-	2.74	0.44	6	-	-	10.5	2.4	1.4	0.3	14.6
15-26	5.7	4.5	0.28	-	2.18	0.41	5	-	-	10.3	2.2	1.6	0.3	14.4
26-38	5.9	4.3	0.08	-	1.56	0.41	4	-	-	5.0	1.2	0.5	0.1	6.8
38-49	6.0	4.2	0.08	-	0.47	0.28	2	-	-	6.4	1.6	0.7	0.5	9.2
49-65	5.8	4.0	0.16	-	1.25	0.62	2	-	-	25.1	6.5	1.7	2.4	35.7
80-80	6.0	4.3	0.19	-	0.92	0.52	2	-	-	29.8	7.9	1.9	3.2	42.8
100-100	5.9	4.1	0.2	-	0.61	0.25	2	-	-	46.7	13.4	2.2	3.2	65.5
115-115	5.9	4.1	0.2	-	0.56	0.17	3	-	-	30.1	8.5	1.9	3.1	43.6

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 %
0-15	61	24.1	73	9.6	-	-	-
15-26	63	23	60	7.6	-	-	-
26-38	64	10.7	34	5.5	-	-	-
38-49	39	23.7	-	1.6	-	-	-
49-65	75	47.5	61	4.4	-	-	-
80-80	79	54.5	65	3.2	-	-	-
100-100	114	57.3	75	2.1	-	-	-
115-115	78	55.7	66	2.0	-	-	-

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
0-15	-	-	-	0.11	0	0.85	0.09	0.65	0.11	-	0.65
15-26	-	-	-	0.12	0.01	0.66	0.09	0.61	0.12	-	0.61
26-38	-	-	-	0.07	0	0.45	0.06	0.28	0.07	-	0.28
38-49	-	-	-	0.17	0.01	5.59	0.27	1.81	0.17	-	1.81
49-65	-	-	-	0.25	0.01	0.99	0.17	0.38	0.25	-	0.38
80-80	-	-	-	0.26	0.01	0.74	0.16	0.25	0.26	-	0.25
100-100	-	-	-	0.26	0.01	0.59	0.17	0.16	0.26	-	0.16
115-115	-	-	-	0.24	0.01	0.65	0.16	0.19	0.24	-	0.19

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
0-15	13.0	0.58	5.5	2.90	0.29	-	66.7	0.69
15-26	13.0	0.54	5.4	2.87	0.29	-	68.6	0.74
26-38	11.4	0.31	3.3	3.10	0.13	-	74.3	0.71
38-49	11.9	0.37	17.8	2.55	0.21	-	50.9	0.63
49-65	19.1	0.78	9.8	1.89	0.66	-	55.7	0.9
80-80	19.9	0.92	10	1.69	0.77	-	54.7	0.94
100-100	19.2	0.96	10.8	1.80	0.86	-	55.6	0.91
115-115	19.5	0.96	10.7	1.77	0.85	-	56.7	0.88

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
0-15	3.7	8.5	0.28	0.06	8.7	32.3	6.9
15-26	3.8	8.0	0.27	0.06	9	33.8	7.1
26-38	5.4	5.2	0.07	0.03	11.1	59.9	9.3
38-49	1.0	7.0	4.08	0.05	7.3	7.6	3.7
49-65	3.1	9.4	0.43	0.04	4.9	15.1	3.7
80-80	3.1	9.4	0.30	0.04	4.7	14.6	3.5
100-100	2.8	8.6	0.10	0.03	4.9	13.7	3.6
115-115	2.9	8.5	0.11	0.03	4.9	14.1	3.7

Clay mineralogy

Depth (cm)	Chlorite	Feldspar	Gibbsite	Goethite	Halloysite	Hematite	Kaolinite	Mica / illite	Mixed-layer	Quartz	Smec	Vermiculite
0-15	-	weak to medium	-	-	-	-	very weak	very weak to weak	weak to medium	very weak to weak	weak to medium	-
15-26	-	weak to medium	-	-	-	-	very weak	-	weak to medium	very weak to weak	weak to medium	-
26-38	-	medium to strong	-	-	-	-	very weak	very weak	weak to medium	very weak to weak	weak to medium	-
49-65	-	weak	-	-	-	-	very weak	very weak	weak to medium	very weak to weak	medium to strong	-
80-80	-	weak	-	-	-	-	very weak	very weak	weak to medium	very weak to weak	strong	-
100-100	-	weak	-	-	-	-	very weak	very weak	weak to medium	very weak to weak	strong	-
115-115	-	weak	-	-	-	-	very weak	very weak	weak to medium	very weak	strong	-

Profile description

Ah 0-20 cm	greyish brown (10YR 5/2, dry) very dark greyish brown (10YR 3/2, moist)silty clay loam,moderate medium subangular blocky,hard very friable non sticky non plastic,patchy thin clay in root channels and pores cutans,many very fine pores and common fine pores,gradual smooth boundary to,
E 20-45 cm	light brownish grey (10YR 6/2, dry) dark greyish brown (10YR 4/2, moist)silty clay loam,massive,hard very firm non sticky non plastic,patchy thin clay in root channels and pores cutans,many very fine pores and common fine pores,abrupt wavy boundary to,
Bcs 45-52 cm	dark greyish brown (10YR 4/2, dry) very dark greyish brown (10YR 3/2, moist)silty clay,moderate medium prismatic,very hard very firm sticky plastic,patchy thin clay on horizontal and vertical pedfaces cutans,few fine pores,clear smooth boundary to,
Bt 52-110 cm	very dark grey (10YR 3/1, dry) very dark grey (10YR 3/1, moist)clay,fine and medium angular blocky,very hard very firm sticky plastic,broken thin clay on horizontal and vertical pedfaces cutans,few very fine pores,
Bth1 84-120 cm	dark reddish brown (5YR 3/4, dry) (5YR 2/4, moist)clay,weak to moderate medium and coarse subangular blocky,slightly hard friable slightly sticky plastic,many distinct clear mottles (5 YR 2/3) and many distinct mottles (2.5 YR 3/8),broken thin clay on horizontal and vertical pedfaces cutans,common fine medium vesicular pores and common medium tubular pores,frequent large spherical soft argillaceous unspecified inclusions,gradual wavy boundary to,
Bth2 120-140 cm	dark reddish brown (5YR 3/4, dry) (5YR 2/4, moist)clay,moderate coarse prismatic parting to moderate coarse subangular blocky,hard firm slightly sticky plastic,many mottles (5 YR 4/8),broken thin clay on horizontal and vertical pedfaces cutans,common fine medium vesicular pores and common medium tubular pores,frequent large spherical soft argillaceous unspecified inclusions,gradual wavy boundary to,
BCr 140-165 cm	dark reddish brown (5YR 3/3, dry) dark reddish brown (5YR 3/3, moist)clay,moderate coarse subangular blocky parting to moderate medium and coarse subangular blocky,hard firm sticky plastic,many mottles (5 YR 4/6) and many mottles (5 YR 3/4),continuous thin clay on horizontal and vertical pedfaces cutans,common fine medium vesicular pores and common medium tubular pores,frequent large spherical soft argillaceous unspecified inclusions,diffuse wavy boundary to,

Kind 1 (parent material) ; Parker (eds), 1984	tuff
Mode of accumulation or deposition of parent material	ejecta ash

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	semi-natural grassland, grazed
Remarks on Land Use / Vegetation	Grassland for cattle and sheep
Rotation scheme ; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	crop rotation scheme not relevant
Status of vegetation; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	primary

Altitude	2550m
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.	plateau
Slope	0%
Topography; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	flat or almost flat

Evidence of alkali ; Soil Survey Manual USDA, 1951	non-alkaline
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 03: Planosol

Characteristics

Reference soil KE003: Planosols

Classification