Reference soil South Africa 02: Ferralsol

ZA002

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 ZA002: Ferralsols

PARENT MATERIAL: Possibly with admixture of sandy material from Dwyka Glacial till.

Classification

WRB 2006

Umbric-Posic-Gibbsic- Ferralsol (Humic Hyperdystric Clayic Chromic)

75-125 cm	ferralic horizon
-	geric

75-125 cm	ferralic horizon
-	geric

FAO-UNESCO-ISRIC 1988

FAO-UNESCO-ISRIC 1974

Ferrali-Humic Cambisol

Humic Ferralsol

0-30 cm	umbric A horizon
30-120 cm	cambic B horizon
-	ferralic

0-30 cm	umbric A horizon
30-75 cm	cambic B horizon
75-120 cm	oxic B horizon
-	high organic matter content in B horizon

Local classification:	Griffin Form, Woodstock Family

Other classification

USDA-SCS (1975)

Haplustox ustic gibbsitic thermic

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
0-20	-	0.3	1.9	6.0	16.8	8.0	33	4.6	16.0	20.6	46.4
20-35	-	0.7	1.6	6.7	17.3	6.7	33	5.1	16.5	21.6	45.4
35-50	-	0.6	2.0	6.2	15.9	6.6	31.3	4.0	17.8	21.8	46.9
50-65	-	0.5	1.6	4.6	12.3	6.8	25.8	8.6	20.5	29.1	45.1
65-80	-	0.4	1.1	5.7	13.6	6.7	27.5	10.4	13.0	23.4	49.1
80-95	-	0.4	1.0	3.6	13.3	7.2	25.5	10.1	12.0	22.1	52.4
95-110	-	0.3	0.8	2.8	12.5	7.3	23.7	10.3	16.0	26.3	50.0
110-125	-	0.2	0.8	2.8	12.3	7.0	23.1	10.2	17.7	27.9	49.0

Water retention characteristics

Depth (cm)	Bulk density kg/dm³	Spec. Surf. Area m²/g	COLE cm/cm	Water disp. clay %	Clay % w/w
0-20	-	-	-	7.3	46.4
20-35	-	-	-	7.9	45.4
35-50	-	-	-	9.5	46.9
50-65	-	-	-	5.7	45.1
65-80	-	-	-	12.6	49.1
80-95	-	75	-	14.5	52.4
95-110	-	-	-	17.7	50.0
110-125	-	77	-	21.8	49.0

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
0-20	5.6	4.5	0.05	-	3.82	0.11	35	1.0	0.7	0.0	0.6	0.2	0.0	0.8
20-35	5.5	4.5	0.04	-	2.86	0.08	36	0.7	0.6	0.0	0.2	0.1	0.0	0.3
35-50	5.2	4.6	0.04	-	2.12	0.05	42	0.5	0.3	0.0	0.0	0.0	0.0	-
50-65	5.1	4.9	0.05	-	0.48	0.04	12	0.0	0.0	0.0	0.0	0.0	0.0	-
65-80	6.0	5.6	0.04	-	0.61	0.02	31	0.0	0.0	0.0	0.1	0.0	0.0	0.1
80-95	5.9	5.9	0.03	-	0.47	0.02	23	0.0	0.0	0.0	0.0	0.0	0.0	-
95-110	5.9	5.9	0.04	-	0.59	0.03	20	0.0	0.0	0.0	0.0	0.0	0.0	-
110-125	5.9	5.9	0.02	-	0.39	0.02	20	0.0	0.0	0.0	0.0	0.0	0.0	-

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 %
0-20	6	13.6	29	13.4	-	-	0
20-35	3	11.8	26	10.0	-	-	0
35-50	-	10.5	22	7.4	-	-	0
50-65	-	9.2	20	1.7	-	-	0
65-80	2	6.1	12	2.1	-	-	0
80-95	-	5.7	11	1.6	-	-	0
95-110	-	6.1	12	2.1	-	-	0
110-125	-	5.3	11	1.4	-	-	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
0-20	-	-	-	0.40	0.05	3.97	1.22	-	-	-	0.23
20-35	-	-	-	0.38	0.05	4.19	1.42	-	-	-	0.25
35-50	-	-	-	0.37	0.05	4.35	1.36	-	-	-	0.21
50-65	-	-	-	0.33	0.05	4.39	1.24	-	-	-	0.17
65-80	-	-	-	0.23	0.06	4.56	0.89	-	-	-	0.18
80-95	-	-	-	0.23	0.06	4.87	0.93	-	-	-	0.18
95-110	9.6	-	-	0.22	0.06	5.26	0.93	0.04	0.07	-	0.20
110-125	-	-	-	0.23	0.07	5.46	0.93	-	-	-	0.24

Elemental composition of the clay

Depth (cm)	SiO2 % w/w	Al2O3 % w/w	Fe2O3 % w/w	CaO % w/w	MgO % w/w	K2O % w/w	Na2O % w/w	TiO2 % w/w
0-20	14.5	41.5	17.3	0.03	0.21	0.15	-	1.56
20-35	15.9	41.1	17.7	0.00	0.24	0.14	-	1.78
35-50	17.4	42.4	17.8	0.00	0.24	0.15	-	1.76
50-65	15.8	42.2	17.7	0.00	0.23	0.16	-	1.54
65-80	14.7	40.8	17.2	0.01	0.21	0.16	-	1.53
80-95	14.5	41.5	17.3	0.03	0.21	0.15	-	1.56
95-110	14.4	41.0	16.8	0.01	0.22	0.14	-	1.48
110-125	15.5	41.7	16.9	0.01	0.20	0.15	-	1.53

Depth (cm)	MnO2 % w/w	P2O5 % w/w	Ign.Loss clay % w/w	Total Clay % w/w	SiO2/Al2O3 mol/mol	SiO2/Fe2O3 mol/mol	SiO2 / R mol/mol	Al2O3/Fe2O3 mol/mol
0-20	0.05	0.28	22.9	98.5	0.6	2.2	0.5	3.8
20-35	0.03	0.24	21.8	98.93	0.7	2.4	0.5	3.6
35-50	0.04	0.21	21.6	101.6	0.7	2.6	0.5	3.7
50-65	0.04	0.21	21.9	99.78	0.6	2.4	0.5	3.7
65-80	0.05	0.28	22.6	97.6	0.6	2.3	0.5	3.7
80-95	0.05	0.28	22.9	98.5	0.6	2.2	0.5	3.8
95-110	0.05	0.28	23.3	97.68	0.6	2.3	0.5	3.8
110-125	0.06	0.28	22.5	98.83	0.6	2.4	0.5	3.9

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
0-20	19.5	0.02	9.0	0.10	0.10	-	53.9	1.28
20-35	18.7	0.00	8.8	0.08	0.08	-	57.6	1.23
35-50	19.8	0.00	9.5	0.09	0.07	-	56.2	1.29
50-65	21.5	0.00	10.2	0.11	0.08	-	53.7	1.37
65-80	22.8	0.00	10.6	0.11	0.07	-	52.1	1.43
80-95	23.2	0.00	10.4	0.10	0.07	-	51.8	1.43
95-110	24.4	0.00	10.8	0.10	0.07	-	49.5	1.49
110-125	25.1	0.00	11.2	0.11	0.07	-	50.0	1.53

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
0-20	3.4	15.6	0.05	0.05	4.7	15.9	3.6
20-35	3.3	13.6	0.04	0.03	5.2	17.4	4
35-50	3.3	12.9	0.05	0.03	4.8	15.7	3.7
50-65	3.3	12.7	0.05	0.03	4.2	14	3.3
65-80	3.4	12.3	0.06	0.05	3.9	13.1	3
80-95	3.5	12.4	0.06	0.04	3.8	13.2	2.9
95-110	3.5	12.8	0.06	0.04	3.4	12.2	2.7
110-125	3.5	12.6	0.07	0.04	3.4	11.9	2.6

Clay mineralogy

Depth (cm)	Chlorite	Feldspar	Gibbsite	Goethite	Halloysite	Hematite	Kaolinite	Mica / illite	Mixed-layer	Quartz	Smec	Vermiculite
0-20	-	very weak to weak	strong	weak to medium	-	-	weak to medium	-	-	very weak to weak	-	weak to medium
20-35	-	very weak to weak	strong	weak to medium	-	-	weak to medium	-	-	very weak to weak	-	weak to medium
35-50	-	-	strong	weak to medium	-	-	weak to medium	-	-	very weak to weak	-	weak to medium
50-65	-	-	strong	weak to medium	-	-	weak to medium	-	-	-	-	weak to medium
65-80	-	-	strong	weak to medium	-	-	weak to medium	-	-	-	-	weak to medium
80-95	-	-	strong	weak to medium	-	-	weak to medium	-	-	-	-	weak to medium
95-110	-	-	strong	weak to medium	-	-	weak to medium	-	-	-	-	weak to medium
110-125	-	-	strong	weak to medium	-	-	weak to medium	-	-	-	-	weak to medium

Sand mineralogy

Depth (cm)	Heavy Frac. sand % w/w	K-Feldspar % w/w	Light Fra. sand % w/w	Opaque % w/w	Plagioclase % w/w	Quartz % w/w
20-35	0.5	1	99.5	76	-	99
50-65	0.4	-	99.6	85	-	100
80-95	0.4	1	99.6	88	-	99
110-125	0.6	-	99.3	87	-	100

Minerals

Depth (cm)	Grenate % w/w	Grossular % w/w	Muscovite % w/w	Rutile % w/w	Sillimanite % w/w	Spinel % w/w
20-35	-	-	-	23	-	-
50-65	-	-	-	18	-	-
80-95	-	-	-	24	-	-
110-125	-	-	-	19	-	-

Profile description

Ah 0-30 cm	(7.5YR 3.5/3, dry) (7.5YR 2.5/2.5, moist)silt loam,fine subangular blocky,hard friable slightly sticky slightly plastic,many very fine and fine roots,non calcareous,gradual smooth boundary to,
30-50 cm	(7.5YR 3.5/4, dry) (7.5YR 3/6, moist)silt loam,porous massive,hard friable slightly sticky slightly plastic,many very fine and fine roots,non calcareous,gradual smooth boundary to,
Bo1 50-75 cm	(7.5YR 4.5/6, dry) (7.5YR 4/7, moist)silt loam,porous massive,hard friable sticky plastic,common very fine pores,common very fine roots,non calcareous,gradual smooth boundary to,
Bo2 75-90 cm	(5YR 4/8, dry) (5YR 4/8, moist)silt loam,porous massive,hard friable sticky plastic,common very fine pores,few very fine and fine roots,non calcareous,gradual smooth boundary to,
Bo3 90-125 cm	red (2.5YR 4/8, dry) (2.5YR 3/7, moist)silt loam,porous massive,hard friable sticky plastic,common very fine and fine pores,few very fine roots,non calcareous,

Kind 1 (parent material) ; Parker (eds), 1984	dolerite
Kind 2 (parent material) (second entry); Parker (eds), 1984	mixed lithology and composition
Mode of accumulation or deposition of parent material	colluvial
Mode of accumulation or deposition of parent material (second entry)	colluvial
Remarks on Parent Materials	dolerite with colluvial admixture of pre-weathered Dwyka tillite
Texture of parent material	loamy
Texture of parent material (second entry)	loamy
Weathering Resistance	poor
Weathering Resistance (second entry)	poor
General characterization of the status of weathering of solid rock	highly
General characterization of the status of weathering of solid rock (second entry)	highly

Land use or vegetation in the immediate vicinity of the site	semi-natural grassland, grazed
Remarks on Land Use / Vegetation	Top soil influenced by pasture practices
Major vegetation type; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	short grassland

Altitude	1135m
Physiographic Unit	slope
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.	hill
Slope	4%
Form of the slope surrounding the site	convex
Topography; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	rolling

Drainage class ; FAO (2006) - Guidelines for soil description	well
Dry From - To	0-40cm
Flooding frequency (FAO, 1986)	never
Kind of ground water table (USDA, 1979)	no groundwater table observed
Moist From - To	40-125cm
Estimated permeability (class) of least permeable part of the profile	moderate
Estimated run off (class)	slow

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)	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 South Africa 02: Ferralsol

Characteristics

Reference soil ZA002: Ferralsols

Classification