Reference soil Australia 33: Umbrisol

AU033

Umbrisols occur mainly in regions where precipitation exceeds considerably the evapotranspiration. They are dominantly associated with acid parent materials.

Characteristics

Soils having an umbric horizon (deep, brownish or blackish surface horizon with a significant accumulation of organic matter and low base saturation). They have no diagnostic horizons other than an anthropedogenic horizon less than 50 cm thick, or an albic or cambic horizon.

Distribution of Umbrisols (rough estimation supplied by soilgrids)

Reference soil AU033: Umbrisols

Classification

WRB 1998

Hapli-Humic- Umbrisol

FAO-UNESCO-ISRIC 1988

FAO-UNESCO-ISRIC 1974

Dystri-Humic Cambisol

Humic Cambisol

Local classification:	HAS: Alpine Humus Soil; FK: Um7.11

Other classification

USDA-SCS (1975)

Haplumbrept udic fine-loamy mixed mesic

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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	-	1.5	3.7	3.1	2	1	11.3	5.9	29	34.9	53.9
15-25	-	3.6	5.3	3.7	2.4	1.2	16.2	9.1	38.8	47.9	35.9
25-40	-	3.8	5.9	4	3.5	3.6	20.8	15	33.8	48.8	30.4
40-53	-	4.3	6.4	4.6	3.3	2.6	21.2	17.1	30.9	48	30.7
53-70	-	5.1	8.4	6.5	5.3	4.3	29.6	17	30.5	47.5	22.9
70-85	-	8.6	11.1	8.2	6.6	4.3	38.8	13.2	26.5	39.7	21.6

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	-	-	-	-	53.9
15-25	-	-	-	-	35.9
25-40	-	-	-	-	30.4
40-53	-	-	-	-	30.7
53-70	-	-	-	-	22.9
70-85	-	-	-	-	21.6

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	5.0	4.1	0.33	-	9.83	0.51	19	-	-	2.2	0.4	0.3	1.0	3.9
15-25	4.8	4.3	0.18	-	4.93	0.28	18	-	-	0.4	0.0	0.1	0.0	0.5
25-40	4.8	4.3	0.1	-	2.59	0.14	18	-	-	0.2	0.0	0.1	0.4	0.7
40-53	4.8	4.3	0.08	-	1.35	0.09	15	-	-	0.2	0.0	0	0.1	0.3
53-70	4.9	4.4	0.08	-	0.90	0.06	15	-	-	0.4	0.0	0	0.3	0.7
70-85	4.9	4.4	0.1	-	0.81	0.06	14	-	-	0.6	0.0	0.1	0.2	0.9

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	6	64.7	120	34.4	-	-	-
15-25	1	53.2	148	17.3	-	-	-
25-40	2	38.1	125	9.1	-	-	-
40-53	1	37.9	123	4.7	-	-	-
53-70	2	37	162	3.2	-	-	-
70-85	3	35.8	166	2.8	-	-	-

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
0-15	26.5	29.7	21.2	0.03	0.51	0.17	-	1.73
15-25	27.2	31.4	21.1	0.02	0.5	0.13	-	1.73
25-40	26.3	32	21.1	0.02	0.51	0.14	-	1.73
40-53	25.2	31.9	20.2	0.02	0.52	0.17	-	1.69
53-70	26.1	33.3	19.2	0.03	0.5	0.18	-	1.58
70-85	24.8	33.4	19.2	0.05	0.52	0.18	-	1.56

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
0-15	0.13	2.1	17.9	100	1.5	3.3	1	2.2
15-25	0.19	2.06	18.6	102.9	1.5	3.4	1	2.3
25-40	0.17	1.8	17.4	101.2	1.4	3.3	1	2.4
40-53	0.12	1.8	17.6	99.2	1.3	3.3	1	2.5
53-70	0.19	2.17	17.6	100.7	1.3	3.6	1	2.7
70-85	0.16	2.07	17.8	99.9	1.3	3.4	0.9	2.7

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	19.6	0.12	21	0.27	0.37	-	25.8	4.21
15-25	23.1	0.09	24.8	0.21	0.37	-	26.9	4.88
25-40	24.2	0.06	25.7	0.22	0.52	-	27.8	5.06
40-53	25.2	0.12	25.2	0.25	0.56	-	28.3	4.97
53-70	24.4	0.18	25.8	0.27	0.48	-	29.1	5.11
70-85	25.1	0.17	26.1	0.24	0.49	-	28.4	5.06

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	1.5	27.7	0.27	1.29	2.2	3.3	1.3
15-25	1.5	20.1	0.31	1.47	2	2.9	1.2
25-40	1.5	16.7	0.27	1.29	1.9	2.9	1.2
40-53	1.6	15.4	0.26	1.29	1.9	3.0	1.2
53-70	1.5	14.1	0.27	1.38	2	3.0	1.2
70-85	1.5	14.2	0.25	1.28	1.9	2.9	1.2

Clay mineralogy

Depth (cm)	Chlorite	Feldspar	Gibbsite	Goethite	Halloysite	Hematite	Kaolinite	Mica / illite	Mixed-layer	Quartz	Smec	Vermiculite
0-15	-	-	weak to medium	-	-	-	weak to medium	-	-	very weak to weak	-	-
15-25	-	-	weak to medium	-	-	-	weak to medium	-	-	very weak to weak	-	-
25-40	-	-	weak to medium	-	-	-	weak to medium	-	-	very weak to weak	-	-
40-53	-	-	weak to medium	-	-	-	weak to medium	-	-	very weak to weak	-	-
53-70	-	-	weak to medium	-	-	-	weak to medium	-	-	very weak to weak	-	-
70-85	-	-	weak to medium	-	-	-	weak to medium	-	-	very weak to weak	-	-

Profile description

Ah1 0-15 cm	dark brown (10YR 3/3, dry) dark reddish brown (5YR 3/2, moist)loam organic highly,strong fine and medium angular blocky parting to crumb,slightly hard friable slightly sticky slightly plastic,highly porous (>60 vol%),many roots,non calcareous 10% HCl,gradual smooth boundary to,
Ah2 15-25 cm	(10YR 3.5/4, dry) dark reddish brown (5YR 3/2, moist)loam slightly gravelly,moderate coarse subangular blocky,slightly hard friable slightly sticky slightly plastic,moderately porous (40-60 vol%),many fine roots,non calcareous 10% HCl,clear smooth boundary to,
Bw1 25-40 cm	(dark) brown (7.5YR 4/4, dry) dark reddish brown (5YR 3/4, moist)clay,moderate medium angular blocky parting to fine granular,slightly hard friable sticky plastic,patchy clay on pedfaces cutans,moderately porous (40-60 vol%),few roots,non calcareous 10% HCl,clear smooth boundary to,
Bw2 40-70 cm	(7.5YR 4.5/4, dry) reddish brown (5YR 4/4, moist)clay,moderate medium angular blocky and moderate medium subangular blocky,slightly hard friable sticky plastic,moderately porous (40-60 vol%),non calcareous 10% HCl,gradual smooth boundary to,
70-90 cm	reddish brown (5YR 4/4, dry) dark reddish brown (5YR 3/4, moist)clay,angular blocky and subangular blocky,hard friable sticky plastic,moderately porous (40-60 vol%),non calcareous 10% HCl,

Kind 1 (parent material) ; Parker (eds), 1984	basalt
Mode of accumulation or deposition of parent material	fluvial
Mode of accumulation or deposition of parent material (second entry)	colluvial
Remarks on Parent Materials	Tertiary basalt
Soil Depth	183cm
Texture of parent material (second entry)	loamy

Land use or vegetation in the immediate vicinity of the site	woodland, grazed
Remarks on Land Use / Vegetation	VEGETATION: woodland of Eucalyptus pauciflora (snow gum) and Poa sieberiana. LAND USE: New England National Park. Extensive cattle grazing.
Rotation scheme ; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	crop rotation scheme not relevant
Major vegetation type; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	woodland

Altitude	1463m
Physiographic Unit	gently sloping valley floor in strongly rolling terrain west of dissected scarp
Physiographic position of the site	slope
Regional landform; McDonald, R.C., Isbell, R.F. et all, 1984; Australian soil and land survey Field Handbook, Inkata Press, Melbourne.	valley
Slope	2%
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	0-180cm
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
Evidence of salt; Soil Survey Manual USDA, 1951	non-saline

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Reference soil Australia 33: Umbrisol

Characteristics

Reference soil AU033: Umbrisols

Classification