soil map units where St Sapa’ata soils is dominant
Soil properties
| Property | Value |
|---|---|
| Geographic distribution | Niuafo’ou |
| Landscape position | From vitric ash on slopes of caldera rim occupying north and west half of the island. |
| Soil parent material | - |
| Slope | Flat (0°) to steep (25-30°) |
| Surface outcrops | - |
| Brief soil profile description | 0-10 cm Black friable loamy sand; 10-35 cm Dark brown friable loamy sand; 35-75 cm Dark brown friable loam; 75-140 cm Black friable sand. |
| Soil profile texture | - |
| Minimum effective rooting depth | 140 cm |
| Soil pH (acidity) | Near neutral |
| Salinity | - |
| Soil fertility under natural conditions | Medium cation exchange capacity (CEC) values; moderate topsoil base status except for potassium (K), which is low; medium phosphorus (P) values; sulphur (S) low at surface increasing with depth. Amorphous materials. |
| Soil moisture regime | - |
| Susceptibility to drought | - |
| Soil drainage | Somewhat excessively drained |
| Susceptibility to waterlogging | - |
| Susceptibility to flooding | - |
