OTR735

Remnant vegetation on steep slopes		Site Code	OTR735	Bleached-Sodic, Magnesic, Brown Kurosol
		Location	Separation Creek
		Landform	Hill
		Geology	Cretaceous Otway Group
		Element	Mid slope
		Slope	40%
		Aspect	Easterly
Horizon	Depth (cm)	Description
A1	0–5	Black (10YR2/1); clay loam; moderate crumb structure; clear smooth boundary to:
A2	5–30	Dark greyish brown (10YR4/2 moist); light brownish grey (10YR6/2 dry); clay loam; weak angular blocky structure; clear smooth boundary to:
B21	30–60	Dark greyish brown (10YR4/2) with yellowish brown (10YR5/6) mottles; medium clay; moderate very fine (4 mm) angular blocky structure; diffuse boundary to:
B22	60–90	Greyish brown (10YR5/2) with yellow (10YR7/8) mottles; medium clay; strong very fine (4 mm) angular blocky structure; clear wavy boundary to:
B3	90–128	Greyish brown (2.5YR5/2) with yellow (2.5YR7/8) mottles; light clay; moderate angular blocky structure; abundant weathering sandstone boundary to:
C	128+	Weathering with lenses of clay between joints.
Management considerations
The texture contrast between the surface soil and the subsoil can have a major effect by reducing and/or redirecting the internal drainage and restricting root growth beyond the upper horizons. Acidic surface soils (topsoil) are often associated with sandy surfaces due to the lack of base minerals and may or may not have organic matter (humose or peaty surfaces). This can restrict the uptake of certain nutrients as well as intolerance for some plant species (due in part to the increasing mobilisation of aluminium and manganese). The sodic subsoil may result in dispersion (and subsequent clogging of pores), restricting water and gas movement through the subsoil. Yellow mottling in the subsoil is an indication of periodic waterlogging/imperfect drainage.

Analytical data

Site OTR735	Sample depth	pH		EC	NaCl	Ex Ca	Ex Mg	Ex K	Ex Na	Ex Al	Ex acidity	FC (-10kPa)	PWP (-150kPa)	KS	FS	Z	C
Horizon	cm	H₂O	CaCl₂	dS/m	%	cmol_c/kg	cmol_c/kg	cmol_c/kg	cmol_c/kg	mg/kg	cmol_c/kg	%	%	%	%	%	%
A1	0-5	5.3	N/R	0.110	0.012	1.4	3.0	1.0	0.7	N/R	N/R	N/R	N/R	4	25	37	25
A2	10-20	4.9	N/R	0.130	0.020	0.2	3.9	0.6	0.9	N/R	N/R	N/R	N/R	2	21	35	36
A2	20-30	5.4	N/R	0.083	0.010	N/R	N/R	N/R	N/R	N/R	N/R	N/R	N/R	N/R	N/R	N/R	N/R
B21	30-60	5.4	N/R	0.098	0.013	0.1	11.6	0.9	2.2	N/R	N/R	N/R	N/R	0.4	6	23	64
B22	60-90	5.4	N/R	0.120	0.018	0.1	15.0	0.7	3.2	N/R	N/R	N/R	N/R	0.4	7	24	63
B3	90-120	5.6	N/R	0.120	0.015	0.3 .	17.0	0.4	4.6	N/R	N/R	N/R	N/R	N/R	N/R	N/R	N/R
C	128-150	5.7	N/R	0.130	0.016	0.6	14.0	0.4	4.2	N/R	N/R	N/R	N/R	N/R	N/R	N/R	N/R

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