Va1R Vaini soils, rolling phase

soil map units where Va1R Vaini soils, rolling phase is dominant

Soil properties

Property Value
Geographic distribution Tongatapu
Landscape position Uplifted ash-mantled coral surface.
Soil parent material
Slope Gently undulating to Rolling (5-15°)
Surface outcrops
Brief soil profile description 0-32 cm Dark reddish brown friable clay; few red lapilli; 32-88 cm Dark reddish brown firm clay; weathered lapilli; 88-170+cm brown heavy, firm clay; clay coatings; on Coral limestone
Soil profile texture
Minimum effective rooting depth 150 cm+
Soil pH (acidity) Near neutral to slightly alkaline
Salinity
Soil fertility under natural conditions High to very high Base saturation (%), calcium (Ca) and magnesium (Mg). phosphorus (P) high in A horizon decreasing with depth; phosphorus (P) retention high; reserve potassium (K) low to very low.
Soil moisture regime
Susceptibility to drought
Soil drainage Well drained
Susceptibility to waterlogging
Susceptibility to flooding

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