soil map units where 6b Namoa shallow peaty clay over basalt is dominant
Soil properties
| Property | Value |
|---|---|
| Geographic distribution | Upolo |
| Landscape position | Soils of the coastlands, valley floors and their margins |
| Soil parent material | from estuarine sediment and organic residue |
| Slope | Usually flat |
| Surface outcrops | Occasional outcrops of smooth massive rock. |
| Brief soil profile description | - |
| Soil profile texture | 15cm peaty clay. 10cm mottled clay loam. on pahoehoe lava |
| Minimum effective rooting depth | <25cm |
| Soil pH (acidity) | Near neutral (pH = pH = 6.7) |
| Salinity | Non saline |
| Soil fertility under natural conditions | High fertility. Base saturation 90-100%. Exchangeable potassium (K) and magnesium (Mg) very high. Available phosphorus (P) low |
| Soil moisture regime | - |
| Susceptibility to drought | 0-3 dry months. Rainfall 2250-3000mm. |
| Soil drainage | Poorly drained |
| Susceptibility to waterlogging | Perched water table due to lava sheet. |
| Susceptibility to flooding | Floods during very high tides associated with sea surges |
