Bindi (Symbol: Bi)

EG200 | Soil Profile No. 33 (Aldrick et al, 1992)

Geology
Devonian marlstone and limestone.

Landform
Rolling low hills, mostly 500-600 m in elevation. The mapping unit may be subdivided into four components. Most of the area comprises long gentle slopes with smaller areas of steeper slopes, particularly northern slopes and rock outcrop, lower slopes and alluvial fans and valley flats and drainage lines.


Undulating low hills of the Bindi map unit (foreground) are almost all cleared for grazing”

Original vegetation Grassy woodland. Soils Component 1: Soils on long gentle slopes These soils form the majority of the soils of this unit. The surface soils are mostly dark reddish brown to dark brown strongly structured friable clay loams. The subsoils are strongly structured medium clays with reddish brown and red colours being predominant. Limestone generally occurs 0.5 and 1 m. One soil pit was excavated on this component (EG208). Component 2: Soils on steeper slopes, particularly northern slopes The soils on this component are generally shallow, less than 0.4 m and limestone may be exposed at the surface. The soil above the rock is similar in nature to component 1. No field or analytical data is available. Component 3: Soils on lower slopes and alluvial fans These soils are deeper than those on the steeper slopes. These are generally deep soils with strongly structured dark greyish brown clay loams overlying dark brown strongly structured clays. Aldrick et al (1992) have given a detailed description of soil on this component (Profile No. 33). Component 4: Soils on valley flats and drainage lines No information is available for the soils on this component, but the surface soils are likely to be dark grey strongly structured clay loams on the level flats and yellow texture contrast soils on low slopes. Land use All of the area is cleared and used for grazing.

Photo: Shallow soils occur on steeper slopes

Yellow texture contrast soils may occur in concave drainage lines

Site EG200

Location: Bindi	Geo. Ref. 0573784E 5886803N
Australian soil classification: Haplic, Lithocalcic, Red DERMOSOL	Gradational soil on limestone
General landscape description: Undulating low hills
Geology: Devonian limestone
Site Description: Upper north facing slope
Land use: Grazing on annual pasture
Original vegetation: Grassy woodland
Mapping unit: Bindi (Component 1)

Soil profile morphology

Surface soil
A1	0 – 17 cm	Dark brown (7.5YR3/2); clay loam; moderate fine (2 – 5 mm) granular structure; firm consistence dry; clear change to:
Subsoil
B21	17 – 30 cm	Reddish brown (2.5YR4/4); medium clay; strong medium (10 – 20 mm) polyhedral structure; very firm consistence dry; few (2 – 10 %) angular limestone pebbles (up to 10 mm in size); gradual change to:
B22	30 – 40 cm	Red (2.5YR4/6); medium clay; strong medium (10 – 20 mm) angular blocky structure; very firm consistence dry; many (20 – 50%) angular tabular limestone pebbles (up to 20 mm in size); gradual change to:
B23	40 – 55 cm	Red (2.5YR4/6); medium clay; very firm consistence dry; abundant (50 – 90 %) angular tabular limestone pebbles (up to 60 mm in size); clear change to:
R	55 – 110+ cm	Fractured limestone becoming impenetrable with depth.

Key profile features

• Lack of texture contrast between the surface (A) horizon and the subsoil (B) horizon.
• The shallow occurrence of limestone rock.

Soil profile characteristics

	pH	Salinity rating	Sodicity	Dispersion	Slaking
Surface soil (A1 horizon)	Strongly acid	Very low	Non sodic	None	Water stable
Subsoil (B21 horizon)	Moderately acid	Very low	Non sodic	None	Slakes partially
Deeper subsoil	Slightly acid	Very low	Non sodic	None	Slakes partially

Horizon	Depth cm	Field texture	pH water	pH CaCl2	EC dS/m	Coarse sand %	Fine sand %	Silt %	Clay %	Field cap. % w/w	Wilt. point % w/w	PAW* water % w/w
A1	0-17	CL	5.3	4.6	0.11	8	18	23	41	34.5	15.5	19.0
B21	17-30	MC	5.9	4.7	0.06	6	10	11	66	30.6	17.0	13.6
B22	30-40	MC	6.2	5.7	<0.05	2	7	16	70	31.8	19.7	12.1
B3	40-55	MC	6.2	6.6	<0.05	13	7	27	50	24.4	13.9	10.5

* PAW is plant available water. This is the difference between the soil’s water content at field capacity and wilting point.

Depth	OrgC#	Total N	Free Fe2O3 % w/w	Exch. Al	Exchangeable cations meq/100 g							Ca:Mg	Na %
cm	%	%		ppm	Ca	Mg	K	Na	Total	H	CEC
0-17	4.3	0.38		<10	7.3	1.5	0.74	0.085	9.6	9.5	19.1	4.9	<1
17-30	1.5	0.14		<10	8	2.9	0.5	0.11	12	6.8	18.8	2.8	<1
30-40	1.3			12	8.7	4	0.33	0.15	13	7.5	20.5	2.2	1
40-55	0.61			14	8.3	3.9	0.29	0.14	13	5.8	18.8	2.2	1

# Organic carbon

Management considerations

Whole profile

• Plant available water here is considered to be moderate. Because of the variability in the depth of soil cover within this mapping unit, many soils will have low to very low water-holding capacity. Effective rooting depth is limited to the depth to rock.

Surface (A) horizons

• The surface soil here is strongly acid. This is inconsistent given the presence of lime in the subsoil. Lime is added to acid soils is to increase the availability of phosphorus and molybdenum so if soil tests taken across the paddock show the soils are deficient, superphosphate should be applied. If no response is observed, lime may used to alleviate the problem.
• The soils are low in soluble salts.
• Potassium levels are moderate and plant responses to potassium fertiliser are unlikely given the present grazing management practices.
• The nutrient holding capacities of the surface (A1 and B21) horizons are moderate (based on the sum of the exchangeable calcium, magnesium, potassium and sodium cations).

Subsoil (B) horizons

• The subsoil would be relatively well drained as there is no sharp increase in clay content at the A/B boundary. The subsoil horizons are non-sodic and not coarsely structured, which will enable plant roots to penetrate easily until they reach rock.

Soil Profile No. 33 (Aldrick et al, 1992)

Location: Bindi	Geo. Ref. 0572400E 5891103N
Australian soil classification: Haplic, Lithocalcic, Brown DERMOSOL	Gradational soil
General landscape description: Undulating low hills
Geology: Devonian limestone
Site Description: Mid-slope of alluvial fan, 10% slope (sample site within an old disused sheepyard)
Land use: Grazing on annual pasture
Original vegetation: Open forest
Mapping unit: Bindi (Component 3)

No photo available

Soil profile morphology

Surface soil
A1	0 – 10 cm	Very dark brown (10YR3/3); clay loam; moderate fine (5 - 10 mm) sub-angular blocky structure; very hard dry; clear change to:
A2	10 – 15 cm	Dark brown (7.5YR3/3); light clay; moderate medium (10 – 20 mm) angular blocky structure; very hard consistence dry; clear change to:
Subsoil
B21	15 – 90 cm	Dark reddish brown (5YR3/4); medium clay; strong medium (10 – 20 mm) sub-angular blocky structure; firm consistence moist; diffuse change to:
B22	90 – 180 cm	Yellowish red (5YR4/6); medium clay; 2% calcareous nodules (2 mm)

Key profile features

• Lack of texture contrast between the surface (A) horizon and the subsoil (B) horizon.

Soil profile characteristics

	pH	Salinity rating	Sodicity	Dispersion	Slaking
Surface soil (A1 horizon)	Moderately acid	Very low	Non sodic
Subsoil (B21 horizon)	Sightly acid	Very low	Non sodic
Deeper subsoil	Slightly alkaline	Very low	Non sodic

Horizon	Depth cm	Field texture	pH water	pH CaCl2	EC dS/m	Coarse sand %	Fine sand %	Silt %	Clay %	Field cap. % w/w	Wilt. point % w/w	PAW* water % w/w
A11	0-5	CL	6.1		0.15	1	24	33	34
A11	5-10	CL	6.0		<0.05
A2	10-15	CL	6.3		<0.05	2	28	27	40
B21	20-30	MC	6.8		<0.05	2	28	24	44
B22	90-120	MC	7.4		<0.05	3	21	14	59
B22	1.5-1.8	MC	7.6		<0.05	3	17	16	59

* PAW is plant available water. This is the difference between the soil’s water content at field capacity and wilting point.

Depth	OrgC#	Total N	Free Fe2O3 % w/w	Exch. Al	Exchangeable cations meq/100 g							Ca:Mg	Na %
cm	%	%		ppm	Ca	Mg	K	Na	Total	H	CEC
0-5	4.2	0.4	2.7		11.8	1.3	2.1	0.05	15.3	11.7	27.0	9.1	<1
5-10
10-15	1.8	0.19	3.0		9.8	0.7	1.0	0.05	11.6	8.8	20.4	14.0	<1
20-30	0.69	0.10	3.6		10.7	0.7	0.7	0.05	12.2	5.6	17.8	15	<1
90-120			4.4		13.9	1.0	1.0	0.2	16.1	11.2	27.3	14	<1
1.5-1.8m			4.0		16.9	2.8	1.0	0.3	21.0	7.8	28.8	6	<1

# Organic carbon

Management considerations

Whole profile

• Plant available water here is considered to be moderate. Roots were found to 60 cm with some at 90 cm.

Surface (A) horizons

• The surface soil here is moderately acid. For pastures, it is unnecessary to add lime.
• Potassium levels are high so plant responses to potassium fertiliser are most unlikely. However it should be noted the sampling site was within an old sheepyard.
• The nutrient holding capacity of the surface (A1 and B21) horizons is moderate (based on the sum of the exchangeable calcium, magnesium, potassium and sodium cations).

Subsoil (B) horizons

• The subsoil would be relatively well drained as there is no sharp increase in clay content at the A/B boundary. The subsoil horizons are non-sodic and not coarsely structured, which will enable plant roots to penetrate easily.