MM173

Site code	MM173
Location	Plains above Leigh River valley (Mount Mercer Road), Cargerie district, south-west Victoria
Landform	Gently undulating basalt plains
Geology	Quaternary Newer Volcanics: extrusive tholeiitic to alkaline basalts, minor scoria and ash
Element	Flat

Profile morphology

Horizon	Depth (cm)	Description
A1	0–15	Dark brown (10YR3/3); fine sandy clay loam; apedal massive structure; weak consistence (dry); clear boundary to:
A2	15–30	Pale brown (10YR6/3), very pale brown (10YR8/2 dry) conspicuously bleached; fine sandy clay loam; very many fine segregations; sharp boundary to:
B21	30–70	Brown (10YR4/3) with brown (10YR5/8) mottles; heavy clay; strong coarse blocky structure; strong consistence (dry); boundary to:
B22	70+	Light olive brown (2.5Y5/4) with red (2.5YR4/6) mottles; heavy clay; strong coarse blocky structure; very firm consistence (dry).

ASC: Eutrophic; Mottled-Mesonatric; Brown Sodosol

Analytical data Source: Government of Victoria, State Chemistry Laboratory.

Site MM173	Sample depth	pH		EC	NaCl	Ex Ca	Ex Mg	Ex K	Ex Na	Ex Al	Ex acidity
Horizon	cm	H₂O	CaCl₂	dS/m	%	cmol_c/kg	cmol_c/kg	cmol_c/kg	cmol_c/kg	mg/kg	cmol_c/kg
A1	0–15	6	N/R	0.21	0.03	1.4	1.4	1	0.6	0	6.9
A2	15–30	5.9	N/R	0.05	N/R	1.1	1.1	0	0.3	0	1.8
B21	30–70	6.1	N/R	0.19	0.03	1.6	1.6	0.2	3.4	N/R	1.2
B22	70+	6.8	N/R	0.71	0.09	2.7	2.7	0.2	4.2	N/R	0.6

Site MM173	Sample depth	FC (-10kPa)	PWP (-1500kPa)	KS	FS	Z	C	Org C	Bulk density
Horizon	cm	%	%	%	%	%	%	%	t m^-3
A1	0–15	28.6	9.7	6	46	30	16	3.3	1.07
A2	15–30	N/R	N/R	12	46	29	13	1	N/R
B21	30–70	N/R	N/R	7	12	7	74	N/R	N/R
B22	70+	N/R	N/R	4	13	12	71	N/R	N/R

Management considerations
These soils have hardsetting topsoils and exhibit a strong texture contrast between the surface soil and the subsoil with a bleached A2 horizon. The bleached A2 horizon is an indication of restricted drainage, poor soil structure (often massive) and low organic matter and nutrients. The fine segregations can restrict root penetration and limit available water holding capacity where there are sufficient amounts, often forming a discontinuous or continuous pan where concentrated (>50%). Sodic and mottled subsoils are other key features of this soil and are an indication of periodic waterlogging.

Improvement of soil structure through increased organic matter would be useful while management options include reduced tillage, improving organic matter content and altering the subsoil through artificial drainage (ripping, mole drainage) and/or chemical amelioration (gypsum) to improve structure.

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