Reference soil Kenya 63: Calcisol

KE063

Calcisols occur in regions with distinct dry seasons, as well as in dry areas where carbonate-rich groundwater comes near the surface.

Characteristics

Soils having a (petro-)calcic horizon (horizon with accumulation of secondary calcium carbonates). In addition, they have no diagnostic horizons other than an ochric or cambic horizon, a calcareous argic horizon, or a gypsic horizon beneath a petrocalcic horizon.

Distribution of Calcisols (rough estimation supplied by soilgrids)

Reference soil KE063: Calcisols

Browsing by camels, goats and cows. Slide: 10,213 -10,219.

Classification

WRB 2006

WRB 1998

Haplic- Calcisol (Sodic Aridic)

Aridi-Endosodic- Calcisol

15-30 cm	cambic horizon
30-140 cm	calcic horizon
-	secondary carbonates
-	aridic

FAO-UNESCO-ISRIC 1988

FAO-UNESCO-ISRIC 1974

Endosodi-Haplic Calcisol

Calcic Xerosol sodic

0-15 cm	ochric A horizon
15-170 cm	cambic B horizon
30-140 cm	calcic horizon
-	sodic

0-15 cm	ochric A horizon
15-170 cm	cambic B horizon
30-140 cm	calcic horizon
-	soft powdery lime

Other classification

USDA-NRCS (1999)
USDA-SCS (1975)	Natrargid aridic isohyperthermic

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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	-	6.9	13.0	20.7	22.0	6.5	69.1	4.0	0.8	4.8	26.0
15-30	-	7.7	13.3	21.2	22.2	3.9	68.3	6.3	1.7	8	23.7
30-53	-	8.9	14.2	20.5	18.8	5.5	67.9	7.8	3.8	11.6	20.5
53-83	-	12.1	11.8	18.0	16.9	3.7	62.5	6.4	10.4	16.8	20.7
83-115	-	12.3	10.0	17.1	18.0	5.0	62.4	3.7	8.3	12	25.5
115-140	-	12.7	8.3	17.4	19.9	3.6	61.9	5.1	7.2	12.3	25.7
140-170	-	5.5	8.5	17.8	22.6	5.8	60.2	4.9	3.4	8.3	31.5

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	-	-	-	-	26.0
15-30	-	-	-	-	23.7
30-53	-	-	-	-	20.5
53-83	-	-	-	-	20.7
83-115	-	-	-	-	25.5
115-140	-	-	-	-	25.7
140-170	-	-	-	-	31.5

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	8.1	7.2	0.18	0.5	0.32	0.03	11	-	-	5.0	2.5	0.8	0.5	8.8
15-30	9.0	7.6	0.98	1.1	0.18	0.01	18	-	-	9.5	6.9	1.0	5.1	22.5
30-53	8.8	7.9	2.70	6.0	0.11	0.01	11	-	-	45.7	12.8	1.1	2.7	62.3
53-83	8.6	7.8	4.00	30.0	0.09	0.00	-	-	-	54.4	9.6	0.6	12.5	77.1
83-115	8.6	7.8	3.40	43.5	0.07	0.00	-	-	-	49.9	7.8	0.3	8.3	66.3
115-140	8.8	7.8	3.20	24.9	0.06	0.01	6	-	-	45.9	13.9	0.3	12.3	72.4
140-170	8.8	7.8	3.80	14.8	0.04	0.01	4	-	-	39.2	16.6	0.4	22.7	78.9

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	147	6.0	-	1.1	-	-	8
15-30	136	16.6	68	0.6	-	-	31
30-53	302	20.6	105	0.4	-	-	13
53-83	521	14.8	100	0.3	-	-	84
83-115	506	13.1	89	0.2	-	-	63
115-140	499	14.5	74	0.2	-	-	85
140-170	415	19.0	60	0.1	-	-	119

Clay mineralogy

Depth (cm)	Chlorite	Feldspar	Gibbsite	Goethite	Halloysite	Hematite	Kaolinite	Mica / illite	Mixed-layer	Quartz	Smec	Vermiculite
0-15	-	very weak	-	-	-	-	very weak	-	-	very weak	weak to medium	-
83-115	-	-	-	-	-	-	very weak	-	-	very weak	very strong	-
140-170	-	-	-	-	-	-	-	-	-	very weak	-	-

Rare clay minerals

Depth (cm)	Boehmite	Cristobalite	Jarosite	Nordstrandite	Palygorskite	Septechlorite
0-15	-	-	-	-	weak	-
83-115	-	-	-	-	strong	-
140-170	-	-	-	-	weak to medium	-

Profile description

Ah1 0-4 cm	yellowish brown (10YR 5/4, dry) yellowish brown (10YR 5/4, moist)coarse sandy loam,single grain,loose very friable slightly sticky slightly plastic,few termite channels,slightly calcareous (0-2%),abrupt smooth boundary to,
Btn 15-30 cm	yellowish red (5YR 5/6, dry) dark reddish brown (5YR 3/4, moist)yellowish red (5YR 5/6, dry) dark reddish brown (5YR 3/4, moist),sandy clay,sandy clay loam,weak to moderate very fine and fine subangular blocky,moderate fine and medium columnar,very hard friable sticky plastic,slightly hard friable slightly sticky slightly plastic,many very fine and few fine and medium pores,many very fine and few fine and medium pores,few fine and medium roots,few fine roots,few termite channels,few termite channels,slightly calcareous (0-2%),slightly calcareous (0-2%),abrupt smooth boundary to,clear smooth boundary to,
Btkn 30-53 cm	brown (7.5YR 5/4, dry) (dark) brown (7.5YR 4/4, moist)sandy clay,weak fine and medium angular blocky,hard friable sticky plastic,many very fine and few fine and medium pores,few very fine and fine roots,frequent powdery irregular soft calcareous crystals,few termite channels,moderately calcareous (2-10%),clear smooth boundary to,
Btk1 53-83 cm	reddish brown (5YR 4/4, dry) reddish brown (5YR 4/4, moist)very gravelly clay,massive parting to granular,loose friable sticky plastic,frequent powdery irregular soft calcareous crystals,common medium gravel fresh quartz fragments,few termite channels,extremely calcareous (>25%),gradual smooth boundary to,
Btk2 83-140 cm	reddish brown (5YR 4/4, dry) reddish brown (5YR 4/4, moist)very gravelly sandy clay,massive parting to granular,slightly hard friable sticky plastic,frequent powdery irregular soft calcareous crystals,common medium gravel fresh quartz fragments,few termite channels,extremely calcareous (>25%),gradual smooth boundary to,
Btki 140-170 cm	reddish brown (5YR 4/4, moist)clay,very weak very fine and fine angular blocky,slightly hard friable sticky plastic,broken thin pressure cutans,few termite channels,strongly calcareous (10-25%),

Kind 1 (parent material) ; Parker (eds), 1984	sediment, unconsolidated
Mode of accumulation or deposition of parent material	marine sediments
Remarks on Parent Materials	Plio-Pleistocene Bay sediments, Marafa beds
Soil Depth	50cm
Texture of parent material	clayey
Weathering Resistance	moderate
General characterization of the status of weathering of solid rock	partially or moderately

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

Land use or vegetation in the immediate vicinity of the site	shrubland, grazed
Remarks on Land Use / Vegetation	VEGETATION: Wooded shrubland with 90% bare soil. LAND USE: Browsing by camels, goats and cows
Status of vegetation; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	degraded
Major vegetation type; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	deciduous shrub

Altitude	170m
Physiographic Unit	sedimentary plain
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.	plain
Slope	1%
Form of the slope surrounding the site	straight
Topography; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	flat or almost flat

Lower limit of a slow permeable or stagnating layer in the profile	30cm
Drainage class ; FAO (2006) - Guidelines for soil description	imperfect
Dry From - To	0-53cm
Flooding frequency (FAO, 1986)	never
Kind of ground water table (USDA, 1979)	no groundwater table observed
Moist From - To	53-170cm
Estimated permeability (class) of least permeable part of the profile	slow
Estimated run off (class)	rapid
Upper limit of a slow permeable or stagnating layer in the profile	15cm

Evidence of alkali ; Soil Survey Manual USDA, 1951	moderately alkaline
Surface cracking	no cracks observed
Slaking of aggregates by tillage, rainfall or frost (USDA/SCS, 1979)	surface capped, crust on drying
Microrelief pattern	none
Rock outcrop class (FAO (2006) - Guidelines for soil description)	none
Evidence of salt; Soil Survey Manual USDA, 1951	slightly saline
Surface stoniness class (FAO (2006) - Guidelines for soil description)	none

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Reference soil Kenya 63: Calcisol

Characteristics

Reference soil KE063: Calcisols

Classification