Reference soil Australia 39: Vertisol

AU039

Vertisols occur dominantly in level landscapes under climates with a pronounced dry season. Vast areas are found in Australia, India, northeastern Africa (Sudan, Ethiopia), southern Latin America and the USA.

Characteristics

Soils having a vertic horizon (a clayey subsurface horizon with polished and grooved ped surfaces ("slickensides") or wedge-shaped or parallelepiped structural aggregates) within 100 cm from the soil surface. They have 30 percent or more clay in all horizons to a depth of 100 cm or more, or to a contrasting layer (lithic or paralithic contact, petrocalcic, petroduric or petrogypsic horizons, sedimentary discontinuity, etc.) between 50 and 100 cm, after the upper 20 cm have been mixed. In addition, Vertisols exhibit wide cracks, which open and close periodically.

Distribution of Vertisols (rough estimation supplied by soilgrids)

Reference soil AU039: Vertisols

Classification

WRB 2006

WRB 1998

Hypocalcic-Sodic-Grumic- Vertisol (Pellic)

Pelli-Hypocalcic- Vertisol (Grumic Hyposodic)

25-95 cm	vertic horizon
-	secondary carbonates

0-25 cm	mollic horizon
25-95 cm	vertic horizon
-	secondary carbonates

FAO-UNESCO-ISRIC 1988

FAO-UNESCO-ISRIC 1974

Sodi-Calcic Vertisol gilgai

Pellic Vertisol sodic

0-25 cm	mollic A horizon
25-95 cm	cambic B horizon
-	slickensides
-	vertic

0-25 cm	mollic A horizon
25-95 cm	cambic B horizon
-	slickensides
-	vertic

Local classification:	Grey clay

Other classification

USDA-SCS (1975)

Pellustert ustic clayey montmorillonitic (calcareous) thermic

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
0-8	-	0.4	0.8	3.0	10.3	18.2	32.7	11.5	10.9	22.4	44.9
8-25	-	0.2	0.6	2.6	9.2	17.8	30.4	13.8	9.7	23.5	46.1
25-35	-	0.2	0.4	2.4	8.6	17.0	28.6	13.8	8.8	22.6	48.8
35-45	-	0.2	0.5	2.3	8.0	16.1	27.1	13.6	8.5	22.1	50.8
45-65	-	0.4	0.6	2.0	7.0	14.3	24.3	12.3	14.7	27.0	48.7
65-72	-	0.2	0.5	1.9	6.5	13.4	22.5	12.5	9.1	21.6	55.9
72-82	-	0.2	0.6	2.3	6.5	12.5	22.1	10.8	10.1	20.9	57.0
82-95	-	0.1	0.3	0.9	6.6	20.9	28.8	8.6	14.4	23.0	48.2
95-105	-	0.0	0.1	0.4	2.7	16.8	20	15.5	17.5	33.0	47.0
105-130	-	0.0	0.1	0.4	5.0	22.7	28.2	11.7	15.3	27.0	44.8
130-135	-	0.1	0.1	0.2	1.0	12.9	14.3	16.7	18.1	34.8	51.0

Water retention characteristics

Depth (cm)	Bulk density kg/dm³	Spec. Surf. Area m²/g	COLE cm/cm	Water disp. clay %	Clay % w/w
0-8	-	-	-	16.3	44.9
8-25	-	-	-	27.1	46.1
25-35	-	-	-	-	48.8
35-45	-	-	-	22.5	50.8
45-65	-	-	-	-	48.7
65-72	-	-	-	34.7	55.9
72-82	-	-	-	-	57.0
82-95	-	-	-	-	48.2
95-105	-	-	-	19.7	47.0
105-130	-	-	-	-	44.8
130-135	-	-	-	-	51.0

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
0-8	6.9	5.7	0.30	4.3	3.69	-	-	-	-	14.6	10.3	2.7	0.1	27.7
8-25	7.8	5.8	0.28	3.0	1.83	-	-	-	-	17.1	14.6	1.1	1.1	33.9
25-35	8.8	6.6	0.44	3.4	1.27	-	-	-	-	19.8	19.2	0.6	2.9	42.5
35-45	9.0	6.7	0.55	4.9	1.01	-	-	-	-	26.1	22.6	0.5	4.3	53.5
45-65	8.6	6.8	2.00	6.1	0.84	-	-	-	-	28.8	25.4	0.5	8.1	62.8
65-72	8.8	6.9	1.26	4.6	0.80	-	-	-	-	22.4	27.4	0.5	8.3	58.6
72-82	8.6	6.7	2.05	5.6	0.81	-	-	-	-	26.8	27.4	0.5	9.2	63.9
82-95	8.8	6.8	1.56	9.4	0.39	-	-	-	-	19.4	25.5	0.3	8.6	53.8
95-105	8.8	6.7	1.55	3.6	0.21	-	-	-	-	12.1	26.2	0.2	10.4	48.9
105-130	8.3	6.2	1.34	2.3	0.12	-	-	-	-	8.8	34.6	0.2	9.9	53.5
130-135	6.6	4.6	1.57	2.7	0.09	-	-	-	-	9.4	28.3	0.2	12.2	50.1

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 %
0-8	66	41.7	93	12.9	-	-	0
8-25	76	44.9	97	6.4	-	-	2
25-35	89	47.7	98	4.4	-	-	6
35-45	108	49.5	97	3.5	-	-	9
45-65	122	51.4	106	2.9	-	-	16
65-72	112	52.5	94	2.8	-	-	16
72-82	122	52.2	92	2.8	-	-	18
82-95	116	46.4	96	1.4	-	-	19
95-105	99	49.4	105	0.7	-	-	21
105-130	114	46.8	104	0.4	-	-	21
130-135	95	52.9	104	0.3	-	-	23

Profile description

Ah 0-8 cm	very dark brown (10YR 2/2, moist) very dark greyish brown (10YR 3/2, dry)clay,moderate medium angular blocky and moderate fine angular blocky,slightly hard friable slightly sticky,patchy thin slickensides cutans,few common fine medium continuous pores and exped and inped pores moderately porous (40-60 vol%),very few small spherical hard calcareous concretions,slightly calcareous 10% HCl,clear smooth boundary to,
Ahi 8-25 cm	black (10YR 2/1, moist) very dark grey (10YR 3/1, dry)clay,moderate coarse angular blocky to moderate medium angular blocky,hard,patchy thin slickensides cutans,slightly porous (<40 vol%),very few small spherical hard calcareous concretions,slightly calcareous 10% HCl,clear smooth boundary to,
Bi1 25-35 cm	(10YR 1.7/1, moist) (10YR 1.7/1, dry) clay,strong coarse prismatic to moderate coarse angular blocky,hard very friable,broken thin slickensides cutans,slightly porous (<40 vol%),calcareous 10% HCl,clear wavy boundary to,
Bi2 35-45 cm	black (10YR 2/1, moist) very dark grey (10YR 3/1, dry)clay,strong coarse prismatic to weak to moderate coarse wedge-shaped angular blocky,hard very friable,continuous thin slickensides cutans,slightly porous (<40 vol%),calcareous 10% HCl,diffuse smooth boundary to,
Bkci1 45-65 cm	very dark grey (10YR 3/1, moist) (2.5Y 3/1, dry)clay,strong coarse and very coarse prismatic to weak to moderate coarse wedge-shaped angular blocky,hard very friable,continuous moderately thick slickensides cutans,few very fine pores slightly porous (<40 vol%),frequent medium irregular soft calcareous concretions,calcareous 10% HCl,clear smooth boundary to,
Bkci2 65-72 cm	very dark grey (10YR 3/1, moist)clay,moderate coarse and very coarse prismatic to moderate medium wedge-shaped angular blocky,hard VE,continuous moderately thick slickensides on vertical pedfaces cutans,slightly porous (<40 vol%),frequent medium irregular soft calcareous concretions hard,strongly calcareous 10% HCl,clear wavy boundary to,
Bkci3 72-82 cm	very dark grey (10YR 3/1, moist)clay,weak very coarse prismatic parting to moderate coarse angular blocky,hard very friable,continuous moderately thick slickensides cutans,slightly porous (<40 vol%),frequent medium irregular soft calcareous concretions,strongly calcareous 10% HCl,clear smooth boundary to,
Bkcg 82-95 cm	very dark grey (10YR 3/1, moist) very dark grey (10YR 3/1, dry)sandy clay,moderate medium angular blocky to weak coarse subangular blocky,hard very friable,many coarse prominent sharp mottles (10 YR 3/1),slightly porous (<40 vol%),frequent medium irregular soft calcareous concretions,strongly calcareous 10% HCl,abrupt smooth boundary to,
95-105 cm	brownish yellow (10YR 6/6, moist) (10YR 7 dry)sandy clay loam,moderate medium subangular blocky to weak coarse subangular blocky,hard very friable,many coarse prominent sharp mottles (10 YR 3/1),slightly porous (<40 vol%),frequent medium irregular soft calcareous concretions,strongly calcareous 10% HCl,abrupt smooth boundary to,
C1 105-130 cm	olive yellow (2.5Y 6/6, moist) (10YR 7/7, dry) sandy clay loam,strongly coherent massive,hard,slightly porous (<40 vol%),frequent medium irregular soft calcareous concretions,strongly calcareous 10% HCl,gradual smooth boundary to,
C2 130-135 cm	greyish brown (2.5Y 5/2, dry)slightly porous (<40 vol%),non calcareous 10% HCl,

Kind 1 (parent material) ; Parker (eds), 1984	basalt
Kind 2 (parent material) (second entry); Parker (eds), 1984	sandstone
Mode of accumulation or deposition of parent material	colluvial
Mode of accumulation or deposition of parent material (second entry)	colluvial
Remarks on Parent Materials	basaltic colluvium mixed with underlying Eocene feldspathic fine sandstone
Soil Depth	135cm
Texture of parent material	clayey
Texture of parent material (second entry)	clayey
Weathering Resistance	moderate
Weathering Resistance (second entry)	moderate
General characterization of the status of weathering of solid rock	highly
General characterization of the status of weathering of solid rock (second entry)	partially or moderately

Intensity of the soil erosion type	slight
Soil erosion type	sheet

Land improvements ; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	land clearing
Land use or vegetation in the immediate vicinity of the site	semi-natural grassland, grazed
Remarks on Land Use / Vegetation	VEGETATION: Savannah woodland cleared to natural grassland; dominant species Eucalyptus sp, Medicago, Medics, Thistle, Aristida, Danthonia, and Panicum. LANDUSE: Site is used for grazing. Locally cultivation of wheat, sorghum, linseed, and sunflower. Site never cultivated or fertilized.
Major vegetation type; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	semi-deciduous woodland

Altitude	408m
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.	lava plain
Slope	4%
Slope Aspect	west
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	imperfect
Dry From - To	0-135cm
Flooding frequency (FAO, 1986)	never
(Estimated) maximum (lower) depth to groundwater table	105cm
Kind of ground water table (USDA, 1979)	perched
(Estimated) minimum (upper) depth to groundwater table	100cm
Estimated permeability (class) of least permeable part of the profile	slow
Estimated run off (class)	medium

Evidence of alkali ; Soil Survey Manual USDA, 1951	slightly alkaline
Surface cracking	large cracks (width more than 1 cm, or depth more than 50 cm)
Slaking of aggregates by tillage, rainfall or frost (USDA/SCS, 1979)	surface partly slaked, round smooth aggregates
Microrelief Height: variation in height	4
Micro relief type: small-scale differences in relief in the direct vicinity of the site (FAO, 1986)	gilgai
Microrelief pattern	polygonal
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 Australia 39: Vertisol

Characteristics

Reference soil AU039: Vertisols

Classification