Location: Gnarwarre, 'South Roxby'
Aust. Soil Class.: Vertic (& Sodic), Self-mulching, Grey VERTOSOL
General Landscape Description: Plain
Site Description: Old proposed SFS 'environmental' research site
Geology: Quaternary - Newer Volcanics
Mapping Unit: Gnarwarre B soil (after Adcock)
SFS 1 (Mapping units within the Gnarwarre SFS Farming Systems trial site)
Soil Profile Morphology:
Surface Soil | ![]() SFS 1 | ||
Ap | 0-20 cm | Very dark greyish brown (10YR 3/2 moist), dark greyish brown (10YR 4/2 dry); light clay (fine sandy), strong, fine (5-15 mm) polyhedral structure; pH 5.6; abrupt change to: | |
Subsoil | |||
B21g | 15-35 cm | Dark grey (10YR 4/1 moist) with many (~50%) yellowish brown (10YR 5/8 moist) mottles; black (10YR 2/1 moist) infill in cracks; heavy clay; very coarse angular blocky and polyhedral structure; cracks; pH 7.5; gradual and irregular change to: | |
B22(k?) | 50/70-100/110 cm | Dark grey (2.5Y 4/1 moist) with greyish brown (2.5Y 5/2 moist) mottles; medium clay; occasional patches of soft calcium carbonate, audible effervescence, bubbles < 2 mm; very coarse to coarse (20-80 mm) lenticular peds; slickensides; pH 8.8; clear change to: | |
B23k | 100/110 cm+ | Dark greyish brown (2.5Y 4/2 moist); light clay to light medium clay; calcium carbonate present; basalt floaters present at 120 cm; pH 9.2. |
pH | Salinity Rating | |||
Surface (A1 horizon) | Moderately Acid | Low | Non-sodic | None1 |
Subsoil (B21 horizon) | Slightly Alkaline | Low | Sodic | None1 |
Deeper subsoil (at 1 m) | Very Strongly Alkaline | Medium | Strongly Sodic | Moderate - Strong |
![]() |
Horizon | Horizon Depth (cm) | pH (water) | pH (CaCl2) | EC dS/m | NaCl | Exchangeable Cations | |||
Ca | Mg | K | Na | ||||||
meq/100g | |||||||||
AP | 0-20 | 5.6 | 4.6 | 0.15 | ![]() | 5.3 | 6.4 | 0.73 | 1 |
B21g | 15-35 | 7.5 | 6.2 | 0.14 | ![]() | 5.5 | 10 | 0.7 | 2.5 |
B22 | 50/70-100/110 | 8.8 | 7.7 | 0.3 | 0.04 | 5.6 | 12 | 0.5 | 4.3 |
B23K | 100/110 | 9.2 | 8.5 | 0.66 | 0.07 | 7.1 | 15 | 0.6 | 5.9 |
Horizon | Horizon Depth (cm) | Extr. Iron | Exchangeable Acidity meq/100g | Field Capacity pF2.5 | Wilting Point pF4.2 | Coarse Sand (0.2-2.0 mm) | Fine Sand (0.02-0.2 mm) | Silt (0.002-0.02 mm) | Clay (<0.002 mm) |
AP | 0-20 | 12 | 11 | 29.4 | 14.3 | 18.5 | 36.1 | 13 | 28 |
B21g | 15-35 | ![]() | ![]() | 34.1 | 16.2 | 15.3 | 36.4 | 12.5 | 35 |
B22 | 50/70-100/110 | ![]() | ![]() | 35.3 | 16.4 | 16.4 | 35.5 | 9.5 | 37.5 |
B23K | 100/110 | ![]() | ![]() | 44.6 | 20.5 | 12.5 | 26.9 | 13 | 43 |