Reference soil Namibia 04: Phaeozem

NA004

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 NA004: Phaeozems

Phaeozem HUMAN INFLUENCE: topsoil is disturbed and grass vegetation is seriously impeded by overgrazing

Classification

WRB 2006

WRB 1998

Haplic- Phaeozem (Pachic)

Pachic- Phaeozem

0-50 cm	mollic horizon
50-90 cm	cambic horizon

FAO-UNESCO-ISRIC 1988

FAO-UNESCO-ISRIC 1974

Pachi-Haplic Phaeozem

Haplic Phaeozem

0-50 cm	mollic A horizon
50-90 cm	cambic B horizon

0-50 cm	mollic A horizon
50-90 cm	cambic B horizon

Local classification:	Dunkelbrauner Talboden der Dornbuschsavanne auf kalklosem Substrat (Scholz, 1962)

Other classification

USDA-NRCS (1999)	Pachic Haplustoll
USDA-SCS (1975)	Pachic Haplustoll ustic fine-loamy mixed thermic

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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
10-30	-	2.6	7.9	10.6	16.5	8.7	46.3	5.4	21.0	26.4	27.3
50-70	-	4.0	9.1	10.2	20.0	8.7	52	5.1	13.3	18.4	31.6
70-90	1	3.6	9.1	10.5	17.8	8.7	49.7	5.7	15.4	21.1	29.2
90-110	3	4.0	8.4	9.9	18.4	9.9	50.6	4.7	18.2	22.9	26.5
110-130	20	5.0	9.5	10.3	17.7	9.3	51.8	8.9	10.0	18.9	29.3

Water retention characteristics

Depth (cm)	Bulk density kg/dm³	Spec. Surf. Area m²/g	COLE cm/cm	Water disp. clay %	Clay % w/w
10-30	-	-	-	-	27.3
50-70	-	-	-	-	31.6
70-90	-	-	-	-	29.2
90-110	-	-	-	-	26.5
110-130	-	-	-	-	29.3

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
10-30	7.4	6.5	0.44	0.0	1.18	0.07	17	-	-	17.8	3.4	1.4	0.1	22.7
50-70	7.6	6.3	0.15	0.0	0.41	0.03	14	-	-	14.8	3.2	0.9	0.0	18.9
70-90	7.5	6.4	0.15	0.0	0.62	0.04	16	-	-	16.3	3.4	1.1	0.1	20.9
90-110	7.8	6.9	0.26	1.1	0.35	0.03	12	-	-	23.3	2.6	0.8	0.1	26.8
110-130	8.0	6.9	0.16	4.2	0.46	0.04	12	-	-	20.8	3.2	0.9	0.1	25

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 %
10-30	105	21.6	79	4.1	-	-	0
50-70	104	18.1	57	1.4	-	-	0
70-90	109	19.1	65	2.2	-	-	1
90-110	173	15.5	58	1.2	-	-	1
110-130	147	17.0	58	1.6	-	-	1

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
10-30	-	-	-	-	-	0.94	-	-	-	-	-
50-70	-	-	-	-	-	0.87	-	-	-	-	-
70-90	-	-	-	-	-	0.81	-	-	-	-	-
90-110	-	-	-	-	-	0.79	-	-	-	-	-
110-130	-	-	-	-	-	0.74	-	-	-	-	-

Profile description

Ah 0-50 cm	very dark brown (10YR 2/2, moist) dark brown (10YR 3/3, dry)sandy clay loam,moderate medium prismatic parting to weak fine and medium subangular blocky,hard friable slightly sticky slightly plastic,common very fine and fine roots between peds,non calcareous,gradual smooth boundary to,
AC 50-90 cm	(7.5YR 3/3, dry) (7.5YR 3/2.5, moist)sandy clay loam,weak medium prismatic parting to weak medium subangular blocky,hard friable slightly sticky slightly plastic,very few calcareous concretions,non calcareous,gradual smooth boundary to,
C 90-120 cm	reddish brown (5YR 4/4, dry) dark reddish brown (5YR 3/3, moist)sandy clay loam,massive,frequent calcareous concretions,non calcareous,

Kind 1 (parent material) ; Parker (eds), 1984	sediment, unconsolidated
Kind 2 (parent material) (second entry); Parker (eds), 1984	sediment, unconsolidated
Mode of accumulation or deposition of parent material	fluvial
Mode of accumulation or deposition of parent material (second entry)	colluvial
Remarks on Parent Materials	loamy alluvial/colluvial material
Texture of parent material	loamy
Texture of parent material (second entry)	loamy
Weathering Resistance	moderate
Weathering Resistance (second entry)	moderate
General characterization of the status of weathering of solid rock	partially or moderately
General characterization of the status of weathering of solid rock (second entry)	partially or moderately

Land use or vegetation in the immediate vicinity of the site	extensive grazing
Remarks on Land Use / Vegetation	VEGETATION: Open woodland with high grasses, bushes and trees (Thornbush Savannah). grass vegetation is seriously impeded by overgrazing. LANDUSE: topsoil is disturbed
Major vegetation type; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	woodland

Altitude	1500m
Physiographic Unit	low-lying plain
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.	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

Drainage class ; FAO (2006) - Guidelines for soil description	moderately well
Dry From - To	0-120cm
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	no cracks observed
Slaking of aggregates by tillage, rainfall or frost (USDA/SCS, 1979)	no surface slaking/crusting observed
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 Namibia 04: Phaeozem

Characteristics

Reference soil NA004: Phaeozems

Classification