LSWW17

Red gum plains and rises near Langkoop		Site Code	LSWW17	Calcic, Mottled_mesonatric, Yellow SODOSOL
		Location	North-east of Langkoop, western Victoria
		Landform	Plain
		Geology	Quaternary swamp and lake deposits: paludal silt and clay
		Element	Plain




Horizon	Depth (cm)	Description
A1	0–15	Brown (7.5YR4/2); loamy sand; weakly structured to massive (structureless); very weak consistence when dry; very few ferruginous nodules; pH 6.9; clear boundary to:
A21	15–40	Light brown (7.5YR6/4), conspicuously bleached; sand; massive (structureless); a few ferruginous nodules; pH 5.7; clear boundary to:
A22	40–47	Pink (7.5YR7/4), conspicuously bleached; sand; massive (structureless); very weak consistence when dry; a few (10-20%) ferruginous nodules (some areas there is a larger percentage of nodules); pH 6.1; sharp boundary to:
B21	47–85	Yellow (10YR7/8) with very coarse distinct dark red and light grey mottles; light clay grading to light medium clay at depth; some organic staining on ped faces; strong medium to coarse, parting to strong coarse blocky structure; abundant yellowish brown clay skin cutans; strong consistence when dry (complete dispersion when worked); pH 6.3:
B22	85–135	Brownish yellow (10YR6/6); medium heavy clay (sandy); moderate very coarse prismatic structure; very firm consistence when slightly moist; few (2%) soft calcareous segregations and hard calcareous/silica nodules; complete dispersion; pH 9.0:
B23	135–190	Pale yellow (2.5Y7/4) with a few patches of light grey mottles; medium clay; moderate very coarse prismatic, parting to strong coarse blocky, parting to moderate coarse polyhedral structure; few manganese flecks and ferruginous nodules; pH 9.2.
Management Considerations
Strong texture contrast between topsoil and subsoil. Sandy topsoil, susceptible to wind, sheet and rill erosion. Bleached A2 horizon with little nutrient capacity. Slightly acidic A21 horizon. Ferric pan. Top of the subsoil slightly acidic and is dispersive following cultivation when wet. Sodic mottled subsoil that shrinks and swells. Alkaline subsoil at depth (>85 cm). Plant Available Water Capacity (PAWC) is considered to be very low (estimated at 45 mm) for this site profile based on an Effective Rooting Depth (ERD) of 45 cm. Rooting depth will be restricted by subsoil conditions, such as; strongly sodic (Exchangeable Sodium Percentage >20%), high soluble salt levels (Chloride >0.1%), poor structure (eg. massive or very coarse, columnar or Prismatic), very high.

Horizon	Depth (cm)	pH (water)	pH (CaCl₂)	EC dS/m	Exchangeable Cations cmol-/kg				Wilting Point (pF4.2)	Coarse Sand %	Fine Sand %	Silt %	Clay %
Horizon	Depth (cm)	pH (water)	pH (CaCl₂)	EC dS/m	Ca	Mg	K	Na	Wilting Point (pF4.2)	Coarse Sand %	Fine Sand %	Silt %	Clay %
A1	0–15	6.9	6.5	0.1	3.1	0.4	0.1	0.1	4.7	41.2	47.8	2	4
A21	15–40	5.7	4.9	<0.05	0.1	<0.1	<0.1	<0.1	1.0	39.9	54.1	2.5	1.5
A22	40–47	6.1	5	<0.05
B21	47–60	6.3	4.7	0.06	2.6	4.5	0.2	2.4	19.0	18.3	23.2	1.5	51
B21	60–85	6.4	5	0.1	2.4	5.2	0.2	2.7	14.9	25.2	28.3	1.5	40.5
B22	85–135	9	8	0.24	3.3	6.8	0.2	4.1
B23	135–190	9.2	8.3	0.26

Site: LSWW17	Land Unit: Red Gum Plains and Rises
*Aust. Soil Class.:* Calcic, Mottled-Mesonatric, Yellow SODOSOL (confidence level 1)

General Land Unit Description:
This land unit comprises the Quaternary lacustrine geology mainly north of the Glenelg River and around Balmoral. The landscape is generally gently undulating plains dissected with small clay plains. The soils in this land unit are similar to many of the soils in the study area – a strong textural contrast between the light textured topsoil and the sodic clay subsoil (Sodosol). The distinguishing feature of the soil type is the presence of an uncemented gravel (ironstone) above the clay, consisting mainly of ferruginised iron nodules mixed with indurated sandstone and manganese nodules. The presence of the bleached horizon (A2) and the mottles in the subsoil indicates impeded internal soil drainage. The presence of manganese flecks and nodules in some of the profiles may indicate the presence of a seasonally perched watertable. The subsoil is often sodic, and is also often strongly dispersive, destroying the structure of the subsoil and resulting in an evident large columnar or prismatic structure. Although often there can be secondary cracks in the large prisms or columns, it remains difficult for plant roots to penetrate deep into the subsoil. The dominant tree species located on this land unit is red gum.

Site Description:

Slope: 1-3%	Geology: Quaternary lacustrine
Landform pattern: Gently to undulating plain	Position in landscape: Mid slope
Internal drainage: Imperfectly drained

Soil Profile Morphology

A1	0-15 cm	Brown (7.5YR4/2) loamy sand, weakly structured to structureless, very weak consistence when dry, very few ferruginised iron nodules. pH 6.9. Clear transition to:
A21	15-40 cm	Light brown (7.5YR6/4) sand, conspicuously bleached when dry, structureless, a few (5-10%) ferruginised iron nodules. pH 5.7. Clear transition to:
A22	40-47 cm	Pink (7.5YR7/4) sand, conspicuously bleached when dry, structureless, very weak consistence when dry, a few (10-20%) ferruginised iron nodules (some areas there is a larger percentage of nodules). pH 6.1. Sharp transition to:
	Subsoil
B21	47-85 cm	Yellow (10YR7/8) light clay grading to light medium clay at depth, very coarse distinct dark red and light grey mottles and yellowish brown clay skins are abundant, some organic staining down ped faces, strong prismatic structure (peds 20-100 mm), breaking to strong blocky structure, (peds 20-50 mm), strong consistence when dry, complete dispersion when worked. pH6.3.
B22	85-135 cm	Brownish yellow (10YR6/6) medium heavy clay (sandy) moderate prismatic structure, (peds >200 mm), very firm consistence when slightly moist, a few (2%) soft calcium carbonate segregations and hard carbonate/silica nodules, complete dispersion. pH 9.0.
B23	135-190 cm	Pale yellow (2.5Y7/4) medium clay with a few patches of light grey mottles, moderate prismatic structure, (peds >200 mm), breaking to strong blocky structure, (peds 20-50 mm), breaking to moderate polyhedral structure, (peds, 20-50 mm), a few (2%) manganese flecks and ferruginised iron nodules. pH 9.2.

Key Profile Features

Sandy topsoil
Strong texture contrast between topsoil and subsoil
Bleached A2 horizon
Sodic subsoil
Mottled subsoil
Top of the subsoil is dispersive following cultivation when wet
Ferruginous pan
Slightly acidic A21 horizon
Top of the subsoil slightly acidic
Alkaline subsoil at depth (>85 cm)
Organic staining down faces and clay skins of the B21 indicates that there is some shrinking and swelling of the soil

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