GT-0318 · Vertisol
South Coast Vertisol
The soil that breathes, swells and cracks.
Soil profile
Tap a horizon to see its details.
Ap0–25 cm
Black clay. In the dry season it opens into cracks up to 5 cm wide.
- Munsell colour
- 10YR 2/1
- Texture
- Clay
Bss125–75 cm
Shiny slickensides, the mark of moving clay.
- Munsell colour
- 10YR 3/1
- Texture
- Clay
Bss275–120 cm
Wedge-shaped blocks, very hard when dry.
- Munsell colour
- 10YR 4/2
- Texture
- Clay
C120–150 cm
Fine sediment with carbonate nodules.
- Munsell colour
- 2.5Y 5/3
- Texture
- Silty clay
When it rains, this soil puffs up like a sponge. When it is hot, it cracks like a jigsaw puzzle. It is a soil that moves by itself!
Vertisols have more than 30% swelling clay. They swell when wet and shrink when dry, forming deep cracks through which surface material falls. This is how the soil mixes itself. They are fertile but hard to work.
Core idea: clay type determines the physical behaviour of a soil. Activity: mould discs of wet clay, let them dry and measure how much they shrink. Links to states of matter and material properties.
Typic Haplustert with more than 55% smectitic clay, slickensides between 25 and 120 cm and seasonal cracks reaching 60 cm. CEC above 50 cmol(+)/kg. Narrow tillage window; slow internal drainage and waterlogging risk in the rainy season.
- USDA Soil Taxonomy
- Typic Haplustert
- WRB 2022
- Pellic Vertisol
See the scientific data
Analytical data by horizon
| Horizon | Depth (cm) | Munsell colour | Texture | pH (H₂O) | O.M. % | CEC |
|---|---|---|---|---|---|---|
| Ap | 0–25 | 10YR 2/1 | Clay | 6.8 | 3.2 | 52 |
| Bss1 | 25–75 | 10YR 3/1 | Clay | 7.2 | 1.9 | 55 |
| Bss2 | 75–120 | 10YR 4/2 | Clay | 7.6 | 1.1 | 50 |
| C | 120–150 | 2.5Y 5/3 | Silty clay | 7.9 | 0.5 | 41 |
CEC: cmol(+)/kg
- 6.8Ap
- 7.2Bss1
- 7.6Bss2
- 7.9C
- 3.2Ap
- 1.9Bss1
- 1.1Bss2
- 0.5C
Downloads
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