soil map units where At Namakaina series is dominant
Soil properties
| Property | Value |
|---|---|
| Geographic distribution | Tarawa, Abatao |
| Landscape position | In pockets of flat or very slightly concave areas |
| Soil parent material | Coralline sand |
| Slope | Flat (0 - 3°) |
| Surface outcrops | No surface stones or boulders |
| Brief soil profile description | The surface horizon varies from 5-20 cm in depth and the colour may vary from dark reddish brown to very dark brown; it is suspected that in some areas there may be a lithic contact between 50 cm and 1 m |
| Soil profile texture | Typically shows about 10 cm of dark brown silt loam compacted by grass roots overlying about 5-10 cm of sand with a little incorporated organic material which in turn rests on pinkish sand which extends to at least 1m |
| Minimum effective rooting depth | 20 cm |
| Soil pH (acidity) | Highly calcareous with high pH |
| Salinity | - |
| Soil fertility under natural conditions | High organic carbon content and CEC in the surface layer; available and total phosphorus levels are very low; exchangeable magnesium high but potassium values are low to very low; distinct smell of sulphide detected in all subsurface horizons. |
| Soil moisture regime | Ustic |
| Susceptibility to drought | Not susceptible to drought due to high water table |
| Soil drainage | Very poorly drained |
| Susceptibility to waterlogging | The lower portions of the profile are permanently saturated with groundwater which is tidal and may come to within 10cm of the surface |
| Susceptibility to flooding | Surface ponding may occur during heavy rainfall, especially at high tide |
