Reference soil South Africa 01: Phaeozem

ZA001

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 ZA001: Phaeozems

CRACKS: Polygonal pattern, up to 2cm wide, down to 25 cm. PARENT MATERIAL: Derived from dolerite and various other rocks.

Classification

WRB 2006

Luvic- Phaeozem (Pachic Clayic Chromic)

0-95 cm	mollic horizon
64-95 cm	argic horizon

0-95 cm	mollic horizon
64-95 cm	argic horizon

FAO-UNESCO-ISRIC 1988

FAO-UNESCO-ISRIC 1974

Pachi-Luvic Phaeozem

Luvic Phaeozem

0-95 cm	mollic A horizon
64-95 cm	argic B horizon

0-95 cm	mollic A horizon
64-95 cm	argillic B horizon

Local classification:	Bonheim Form, GlengaziFamily

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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
0-20	-	1.5	1.4	1.5	2.6	2.5	9.5	14.1	21.3	35.4	55.1
20-46	-	5.5	2.5	1.7	2.5	2.3	14.5	8.8	18.9	27.7	57.8
46-64	-	4.6	2.2	1.6	2.1	2.0	12.5	7.9	20.4	28.3	59.2
64-75	-	1.5	0.7	0.6	1.4	1.5	5.7	4.8	22.0	26.8	67.5
75-95	-	0.5	0.4	0.3	1.5	2.0	4.7	5.5	26.4	31.9	63.4
95-110	-	0.1	0.2	0.2	3.4	4.2	8.1	9.1	36.3	45.4	46.5

Water retention characteristics

Depth (cm)	Bulk density kg/dm³	Spec. Surf. Area m²/g	COLE cm/cm	Water disp. clay %	Clay % w/w
0-20	-	-	-	-	55.1
20-46	-	-	-	-	57.8
46-64	-	-	-	-	59.2
64-75	-	-	-	-	67.5
75-95	-	-	-	-	63.4
95-110	-	-	-	-	46.5

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
0-20	6.3	5.3	0.24	-	3.12	0.16	20	-	-	12.8	6.9	0.2	0.4	20.3
20-46	6.3	5.3	0.14	-	2.00	0.12	17	-	-	10.0	6.4	0.1	0.4	16.9
46-64	6.6	5.3	0.18	0	1.30	0.10	13	-	-	10.3	7.6	0.1	0.9	18.9
64-75	6.7	5.3	0.16	0	0.90	0.07	13	-	-	12.8	7.5	0.1	0.9	21.3
75-95	7.0	5.3	0.16	0	0.48	0.04	12	-	-	17.0	15.0	0.1	1.3	33.4
95-110	7.1	5.4	0.19	0	0.22	0.02	11	-	-	20.0	17.1	0.1	1.3	38.5

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	58	35.2	64	10.9	-	-	1
20-46	62	27.2	47	7.0	-	-	1
46-64	68	27.8	47	4.5	-	-	3
64-75	68	31.3	46	3.1	-	-	3
75-95	87	38.5	61	1.7	-	-	3
95-110	101	38.1	82	0.8	-	-	3

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	-	-	-	-	-	6.4	-	-	-	-	-
20-46	-	-	-	-	-	6.7	-	-	-	-	-
46-64	-	-	-	-	-	6.8	-	-	-	-	-
64-75	-	-	-	-	-	6.4	-	-	-	-	-
75-95	-	-	-	-	-	5.1	-	-	-	-	-
95-110	-	-	-	-	-	3.6	-	-	-	-	-

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	40.2	24.0	19.0	0.10	0.67	0.28	-	1.31
20-46	41.8	25.7	16.9	0.05	0.72	0.31	-	1.01
46-64	41.5	27.3	17.1	0.08	0.61	0.34	-	0.99
64-75	42.6	27.9	15.6	0.10	0.71	0.36	-	0.80
75-95	42.5	26.1	16.4	0.17	0.76	0.32	-	0.96
95-110	45.7	27.4	14.6	0.14	1.10	0.44	-	0.65

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	0.25	0.27	11.3	97.38	2.8	5.6	1.9	2
20-46	0.28	0.17	11.5	98.6	2.8	6.6	1.9	2.4
46-64	0.29	0.15	11.9	100.3	2.6	6.4	1.8	2.5
64-75	0.18	0.14	11.8	100.19	2.6	7.3	1.9	2.8
75-95	0.23	0.18	11.7	99.2	2.8	6.9	2	2.5
95-110	0.17	0.16	10.8	101.16	2.8	8.3	2.1	2.9

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	14.2	0.55	12.8	0.24	0.50	-	58.5	2.01
20-46	15.5	0.44	14.9	0.24	0.47	-	54.8	1.92
46-64	18.8	0.37	15.4	0.28	0.57	-	51.1	1.63
64-75	22.3	0.48	14.4	0.30	0.88	-	49.0	1.28
75-95	23.1	0.75	13.9	0.28	1.44	-	48.6	1.12
95-110	22.3	1.18	14.1	0.27	1.83	-	49.8	1.16

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	1.7	11.0	0.29	0.07	7	12.1	4.4
20-46	1.6	11.2	0.57	0.05	6	9.8	3.7
46-64	1.9	10.9	0.55	0.05	4.6	8.8	3.0
64-75	2.4	11.1	0.22	0.02	3.7	9.1	2.6
75-95	2.6	10.6	0.20	0.00	3.6	9.3	2.6
95-110	2.5	9.2	0.17	0.00	3.8	9.4	2.7

Clay mineralogy

Depth (cm)	Chlorite	Feldspar	Gibbsite	Goethite	Halloysite	Hematite	Kaolinite	Mica / illite	Mixed-layer	Quartz	Smec	Vermiculite
0-20	-	-	-	-	-	-	weak to medium	-	very weak to weak	weak to medium	very weak to weak	-
20-46	-	-	-	-	-	-	weak to medium	-	weak to medium	very weak to weak	very weak to weak	-
46-64	-	-	-	very weak to weak	-	-	strong	-	weak to medium	very weak to weak	very weak to weak	-
64-75	-	-	-	very weak to weak	-	-	strong	-	weak to medium	very weak to weak	very weak to weak	-
75-95	-	-	-	very weak to weak	-	-	strong	-	weak to medium	very weak to weak	very weak to weak	-
95-110	-	-	-	-	-	-	strong	-	weak to medium	very weak to weak	weak to medium	-

Profile description

Ah1 0-20 cm	very dark brown (10YR 2/2, dry) very dark brown (10YR 2/2, moist)clay,strong fine subangular blocky,hard friable slightly sticky slightly plastic,many exped pores and few inped pores,common very fine and few medium roots,non calcareous,clear smooth boundary to,
Ah2 20-46 cm	very dark brown (7.5YR 2/2, dry) very dark brown (7.5YR 2/2, moist)slightly gravelly clay,moderate fine subangular blocky and moderate very fine subangular blocky,hard friable slightly sticky slightly plastic,many exped pores and few inped pores,few medium roots,non calcareous,gradual smooth boundary to,
46-64 cm	(5YR 2.5/3, dry) (5YR 2/3, moist)slightly gravelly clay,fine subangular blocky and very fine subangular blocky,hard friable slightly sticky slightly plastic,patchy thin clay cutans and humus on pedfaces,many exped pores and few inped pores,few medium roots,non calcareous,clear smooth boundary to,
Bt1 64-75 cm	dark reddish brown (5YR 3/3, dry) dark reddish brown (5YR 3/3, moist)slightly gravelly clay,moderate medium prismatic to strong fine subangular blocky,hard friable slightly sticky slightly plastic,continuous thick clay and humus cutans on horizontal and vertical pedfaces,many exped pores and few inped pores,few medium roots,non calcareous,clear wavy boundary to,
Bt2 75-95 cm	dark reddish brown (5YR 3/3, dry) dark reddish brown (5YR 3/3, moist)slightly gravelly clay,moderate medium prismatic parting to moderate medium subangular blocky,hard friable slightly sticky slightly plastic,common (5-15%) medium prominent sharp mottles (7.5YR 8/6),continuous thick clay and humus cutans on horizontal and vertical pedfaces,many exped pores and few inped pores,few medium roots,non calcareous,clear wavy boundary to,
C 95-110 cm	reddish yellow (7.5YR 6/6, moist) reddish yellow (7.5YR 7/6, dry)clay,rock structure,5YR2/2 and 5YR3/4 (dark reddish brown) mottles,5YR2/2 mottles,broken moderately thick clay cutans in cracks,dominant strongly weathered saprolite fragments,non calcareous,

Kind 1 (parent material) ; Parker (eds), 1984	dolerite
Mode of accumulation or deposition of parent material	residual material
Remarks on Parent Materials	solifluction material, mainly derived from dolorite, a mixture of Ecca shale
Texture of parent material	clayey
Weathering Resistance	poor
General characterization of the status of weathering of solid rock	partially or moderately

Land use or vegetation in the immediate vicinity of the site	non-agricultural land
Remarks on Land Use / Vegetation	Wooded grassland with Acacia spp. Regular burning of grass
Major vegetation type; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	woodland

Altitude	640m
Physiographic position of the site	upper slope
Regional landform; McDonald, R.C., Isbell, R.F. et all, 1984; Australian soil and land survey Field Handbook, Inkata Press, Melbourne.	plateau
Slope	4%
Slope Aspect	north-north-east
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	0-110cm
Flooding frequency (FAO, 1986)	never
Kind of ground water table (USDA, 1979)	no groundwater table observed
Estimated permeability (class) of least permeable part of the profile	moderate
Estimated run off (class)	medium

Evidence of alkali ; Soil Survey Manual USDA, 1951	non-alkaline
Surface cracking	small cracks (width less than 1 cm, or depth less than 50 cm)
Micro relief type: small-scale differences in relief in the direct vicinity of the site (FAO, 1986)	level
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 01: Phaeozem

Characteristics

Reference soil ZA001: Phaeozems

Classification