Location: Bessiebelle
Australian Soil Classification: Bleached-Vertic, Mesotrophic, Brown CHROMOSOL
General Landscape Description: Level Plain
Site Description: Flat
Land Unit: Strathdownie
Geology: Quaternary lacustrine sediments
General Land Unit Description:
This land unit comprises the Quaternary lacustrine geology south of the Glenelg River. The lacustrine deposits include lagoonal, swamp and local colluvial deposits formed in low-lying wetlands and depressions between stranded beach ridges. Parent material in this land unit comprises of sand, silt, sandy clay, peat, marl and freshwater limestone, occurring in relatively unconsolidated forms.
The soils are variable throughout this land unit due to varying depositional environments. A common soil type is a strong texture contrast soil (Chromosol) commonly with a bleached A2 horizon and a mottled subsoil (indicative of impeded internal drainage). The sandy topsoil can be very deep in some soils. Vertosols are also common on the plains and swales in between the dunes. Podosols occur on the flats as well as on the dunes and that may have been mapped as part of this land unit due to restrictions of scale. Many of the soils are poorly drained and exhibit signs of a perched watertable.
This site has a 1.5 year old Eucalyptus globulus plantation on ex-agricultural land. The site is probably a heathland/bog. The trees in this plot have been severely affected by waterlogging.
Soil Profile Morphology
Surface
A1 | 0-20 cm | Dark brown (7.5YR3/2) fine sandy loam; weak granular structure (5-10 mm); weak consistence when dry; very few medium ferruginous nodules common very fine macropores; areal porosity 0.1%; many medium roots; clear and smooth transition to: | |
A2 | 20-40 cm | Pale brown (10YR6/3) fine sandy loam; massive structure; very weak consistence when dry; few medium ferruginous nodules; many very fine macropores; areal porosity 0.8%; few fine roots; clear and smooth transition to: | |
Subsoil | |||
B1 | 40-50 cm | Light yellowish brown (10YR6/4), fine sandy clay; weak polyhedral structure (10-20 mm); weak consistence when dry; few medium ferruginous nodules; many very fine macropores; areal porosity 0.6%; few very fine roots; clear and smooth transition to: | |
B21 | 50-80 cm | Brown (10YR5/3), light medium clay; moderate polyhedral structure (20-50 mm) parting to strong granular structure (10-20 mm); weak consistence when moderately moist; few very fine macropores; areal porosity 0.05%; few very fine roots; diffuse and smooth transition to: | |
B22 | 80-125 cm | Brownish yellow (10YR6/6) with few medium faint yellowish red (5YR5/8) mottles, light medium clay; moderate polyhedral structure (50-100 mm) parting to moderate granular structure (5-10 mm); very weak consistence when moderately moist; few very fine macropores; areal porosity 0.05%; few very fine roots; diffuse and smooth transition to: | |
B23 | 125-150 cm | Light grey (10YR7/1) with many coarse distinct brownish yellow (10YR6/8) and red (2.5YR4/6) mottles, medium clay; moderate subangular blocky to lenticular structure (20-50 mm) parting to moderate granular structure (5-10 mm); weak consistence when moist; few very fine macropores; areal porosity 0.01%; no roots observed. | |
150-300 cm | Grey medium to heavy clay (slickensides) with red/yellow mottles of ironstone concretions, some green/blue colouration. | ||
300-380 cm | Blue green clays (possibly anaerobic), slickensides, ironstone concretions in mottles, some limestone fragments; few remnant roots to 380 cm. |
- | pH | Salinity | ||
Surface Soil (A1 horizon) | Very Strongly Acid | Medium | Non-Sodic | None |
Subsoil (B1 Horizon) | Moderately Acid | Very Low | Non-Sodic | None |
Deeper Subsoil (80-125 cm) | Slightly Acid | Low | Slightly Sodic | None |
Horizon | Horizon Depth (cm) | pH (water) | pH (CaCl2) | EC dS/m | Exchangeable Aluminium ppm | Exchangeable Acididty meq/100g | Exchangeable Cations | Coarse Sand (0.2-2.0 mm) % | Fine Sand (0.02-0.2 mm) % | Silt (0.002-0.02 mm) % | Clay (<0.002 mm) % | Field Capacity % w/w | Wilting Point % w/w | |||
Ca | Mg | K | Na | |||||||||||||
meq/100g | ||||||||||||||||
A1 | 0-20 | 4.9 | 4.4 | 0.11 | 47 | 1.9 | 0.49 | 0.26 | 0.07 | 37 | 40 | 11 | 7 | 18.5 | 6.7 | |
A2 | 20-40 | 5.7 | 4.9 | <0.05 | <10 | 1.3 | 0.39 | 0.14 | 0.07 | 42 | 40 | 9 | 9 | 11.3 | 3.4 | |
B1 | 40-50 | 6.0 | 5.3 | 0.07 | <10 | 4.8 | 2.7 | 1.9 | 0.24 | 0.28 | 33 | 36 | 11 | 22 | 14.6 | 8.3 |
B21 | 50-80 | 6.0 | 5.7 | 0.28 | <10 | 11 | 4.3 | 5.4 | 0.20 | 0.7 | 9 | 10 | 7.5 | 74 | 43.9 | 28.8 |
B22 | 80-125 | 6.5 | 6.2 | 0.37 | 10 | 4.4 | 5.9 | 0.10 | 1.4 | 6 | 7 | 13.2 | 74 | 48.5 | 31.1 | |
B23 | 125-180 | 7.5 | 7.0 | 0.34 |