Briagolong (Symbol: Br)

EG253 | Profile No. 62 (Aldrick et al, 1992) | Sample No. GR2 (Little and Ward) | Sample No. GR51 (Little and Ward)

Geology

Pleistocene alluvial sediments. On the geology maps these areas are mapped as Qp4, which is the third youngest of the six alluvial terraces deposited during the Pleistocene Period. Larger areas of this map unit occur in the Maffra area.

This photo, looking north on the Bairnsdale – Bengworden road about 3 km south of Princes Highway, shows the break
in the landscape between the Fernbank (higher) and the Briagolong (lower) Map units.

Landform

This map unit occurs on the almost level plains to gently undulating plains immediately west and south of Bairnsdale and the gently undulating plains west of Johnsonville. The map unit is somewhat dissected where it adjoins drainage lines and streams.

Original vegetation

Plains grassy woodland

Soils

The soils are texture contrast soils. The surface soils are strongly to moderately acidic dark greyish brown fine sandy loams to sands and often have a bleached subsurface soil. Sodic and slightly acid yellowish brown to brownish yellow dense and coarsely structured medium to heavy clays occur at a variable depth, generally before 50 cm with grey or strong brown mottles in the deeper subsoil. Quartz pebbles may occur throughout the profile, often in the surface horizons.

Previous maps and reports

This map unit is included within the Red Gum 1 and 2 and Salt Creek Land Systems as described by Aldrick et al. (1992)

Land use

Most of the land is cleared, mainly for grazing.

EG253

Location: Nicholson	Geo. Ref.: 566100E 5810900N
Australian Soil Classification: Magnesic (and Eutrophic), Subnatric, Brown SODOSOL	Sodic brown texture contrast soil
General landscape description: Undulating rises
Geology: Pleistocene alluvial sediments
Site description: Upper slope, south aspect, 5% slope
Land use: Grazing
Original vegetation: Grassy woodland
Map unit: Briagolong

Photo looking north-east from near the soil pit

Soil Profile Morphology

Surface soil

A	0 – 15cm	Very dark greyish brown (10YR3/2); fine sandy clay loam; weak medium subangular blocky structure; firm consistence dry; abrupt change to:	EG253 profile
Subsoil
B21	15 – 40 cm	Dark brown (10YR4/3); medium clay; strong very coarse columnar structure, parting to strong fine angular blocky; very strong consistence dry; few (<10 %) rounded cobbles (<200 mm); diffuse change to:
B22	40 – 90 cm	Greyish brown (2.5Y5/3); light medium clay; strong coarse very prismatic to lenticular structure, parting to strong fine angular blocky; very strong consistence moderately moist; diffuse change to:
B23	90 – 120 cm	Greyish brown (2.5Y5/3) few (<10%) coarse dark yellowish brown (10YR4/8) mottles; light medium clay; strong medium prismatic structure; very firm moderately moist; diffuse change to:
C1	120 – 170 cm	Light grey (2.5Y7/3) with many (20-50%) very coarse (>30 mm) yellowish brown (10YR5/8) mottles; light clay; massive.

Key Profile Features

• Strong texture contrast between the surface (A) and subsoil (B) horizons
• Quartz cobbles present in the upper subsoil.

Soil profile characteristics

	pH	Sodicity	Slaking	Dispersion Dry	Dispersion Remoulded
Surface soil (A horizon)	Strongly acid	Non-sodic	Water stable	Nil (2 hours), Nil (20 hours)	Slight (2 hours), Slight (20 hours)
Subsoil (B21 horizon)	Moderately acid	Sodic	Water stable	Nil (2 hours), Slight (20 hours)	Strong (2 hours), Strong (20 hours)
Deep subsoil (B23 horizon)	Slightly alkaline	Strongly sodic	Considerable	Slight (2 hours), Slight (20 hours)	Slight (2 hours), Strong (20 hours)

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
A	0-15	FSCL	5.4	4.6	0.07	17	55	17	7	17	4.8	12.2
B21	15-40	MHC	5.9	4.8	0.13	9	31	12	46	28.1	16.7	11.4
B22	40-90	MC	7.8	6.6	0.26	7	36	15	38	27.1	15.6	11.5
B23	90-120	MC	7.9	7.3	0.96	2	27	25	41	35.3	13.3	12.0
B24	120-170	LC	7.7	7.2	0.89	1	43	29	24	33.1	14.1	19.0

* PAW refers to 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	Exch. Al	Exchangeable cations cmol(+)/kg							Ca:Mg	ESP
cm	%	%	% w/w	ppm	Ca	Mg	K	Na	Total	H	CEC
0-15	1.9	0.15		25	1.7	1.1	0.1	<0.1	3	6	9	1.6	4
15-40				42	1.7	7.7	0.3	1.2	11	9.5	20.5	0.3	6
40-90				<5	0.8	7.6	0.2	2.4	11	3.4	14.4	0.1	17
90-120				<5	0.7	8.4	0.2	4.3	14	2.9	16.9	0.1	25
120-170				<5	0.6	6.1	0.1	2.5	9.3	1.8	11.1	0.1	23

# Organic carbon

Management considerations

Whole profile

• The plant available water capacity is considered to be low (estimated at 38 mm) based on an effective rooting depth of 30 cm. The dense upper subsoil is likely to restrict the effective rooting depth.

Surface (A) horizons

• The surface soil is strongly acid but it is unlikely the pastures could show a response to lime.
• The low wilting point indicates plants will be able to use very light rains when the soil is dry. Due to the low water storage capacity, plants will soon suffer moisture stress if follow-up rains don’t occur.
• Potassium levels are very low and a response to added potassium would be expected.
• Both the water holding capacity and the nutrient holding capacity is low. This can be enhanced by increasing the organic matter content of the soil by improving grazing management.

Subsoil (B) horizons

• The subsoil is dense, sodic and cracks when dry. This will significantly restrict root growth in the subsoil.
• Soluble salt levels increase with depth and are high in the deeper subsoil. This may restrict the growth of deeper rooted salt sensitive species.

Profile No. 62 (Aldrick et al, 1992)

Location: 2 km south of Bairnsdale	Geo. Ref.: 552900E 5810800N
Australian Soil Classification: Eutrophic, Mottled-Subnatric, Brown SODOSOL (Thick very gravelly)
Map unit: Briagolong. Deep gravelly brown sodic texture contrast soil

Depth cm	Colour	Texture	pH	TSS %	Grv %	CS %	FS %	Silt %	Clay %	Org C %	Tot N %	Exchangeable cations cmol(+)/kg					Ca:Mg	ESP
												Ca	Mg	K	Na	CEC
0-10	Very dark greyish brown	SL	4.8	0.02	16	24	49	16	9	1.9	0.16	1.7	0.8	0.2	0.1	12.5	1.31	1
30-50	Mottled yellowish brown and reddish brown	SL	5.6	0.01	57	28	51	13	6			1.0	0.4	0.1	0.1	2.9	2.5	3
60-75	Mottled yellowish brown and reddish brown	HC	6.4	0.05	7	8	17	4	70			2.9	8.2	0.2	3.1	23.7	0.4	13
90-120	Mottled yellowish brown and reddish brown	HC	5.5	0.05	7	11	24	8	56			1.2	6.9	0.2	3.0	18.7	0.2	16

* Quartz gravel not included in particle size analysis

Sample No. GR2 (Little and Ward)

Location: Simms Road, Johnsonville	Map ref.: 570600E 5812650N
Australian Soil Classification: Eutrophic, Mottled-Subnatric, Brown SODOSOL
Map unit: Briagolong

Depth cm	Colour	Texture	pH	TSS %	Grv %	CS %	FS %	Silt %	Clay %	Org C %	Tot N %	Exchangeable cations cmol(+)/kg					Ca:Mg	ESP
												Ca	Mg	K	Na	CEC
0-10	Grey	FSL	5.5	0.04		10	45	26	4	3.0	0.3	2.9	2.2	0.48	.06	14.9	1.3	0
20-30	Mottled yellowish brown and dark brown	LMC	6.3	0.05		9	30	22	39			2.5	8.7	0.13	1.8	17.2	0.3	10
120-135	Mottled greyish brown and yellowish brown	LMC	6.7	0.22		0	23	34	42			1.4	11.2	0.08	6.2	19.0	0.1	33

Gravel (> 2mm) and stones not included in analysis

Sample No. GR51 (Little and Ward)

Location: Buchannan’s Road., Hillside	Geo. Ref.: 546300E 5810250N
Australian Soil Classification: Magnesic (and Eutrophic), Mottled-Subnatric, Brown SODOSOL	Brown sodic texture contrast soi
Map unit: Briagolong

Depth cm	Colour	Texture	pH	TSS %	Grv %	CS %	FS %	Silt %	Clay %	Org C %	Tot N %	Exchangeable cations cmol(+)/kg					Ca:Mg	ESP
												Ca	Mg	K	Na	CEC
0-10	Dark greyish brown	SL	5.7	0.02		35	40	12	10	0.9	0.07	1.6	1.1	0.14	0.04	7.0	1.5	0
20-30	Mottled light brownish grey and strong brown	MC	6.0	0.03		19	22	7	51			1.8	7.4	0.12	1.7	18.6	0.2	9
120-135	Mottled yellowish brown and greyish brown	MC	6.3	0.16		11	19	17	52			1.4	8.6	0.10	5.9	18.0	0.2	33

Gravel (> 2mm) and stones not included in analysis