soil map units where Au Tanaea series is dominant
Soil properties
| Property | Value |
|---|---|
| Geographic distribution | Tarawa, Abatao |
| Landscape position | This soil dominates the areas close to the lagoon edge. |
| Soil parent material | coralline sand |
| Slope | Flat (0 - 3°) |
| Surface outcrops | Some coral stones and gravels on surface |
| Brief soil profile description | Topsoil colours are dark brown to very dark brown; textures range from sandy loam to loamy sand and the depth varies from 5-15 cm. The CA horizon colours vary from very pale brown to light brownish grey. The depth to the water table varies from 80-110 cm depending on the tide. |
| Soil profile texture | Typically shows a shallow dark brown loamy sand having weakly developed granular structure overlying about 25 cm of structureless sand in which has been a small amount of organic matter; this overlies structureless sand to depths greater than 1 m. |
| Minimum effective rooting depth | 100 cm |
| Soil pH (acidity) | Highly calcareous with high pH |
| Salinity | - |
| Soil fertility under natural conditions | Low CEC and lower levels of organic carbon and nitrogen in the topsoil than found for other soils on the islet, phosphorus and potassium levels are very low. |
| Soil moisture regime | Ustic |
| Susceptibility to drought | Upper portion of profile dries out in dry periods. |
| Soil drainage | Excessively drained |
| Susceptibility to waterlogging | The lower portions of the profile are wet due to the groundwater table which regularly encroaches within 1 m of the surface and is influenced by tides. |
| Susceptibility to flooding | Never floods |
