Reference soil Nigeria 13: Plinthosol
Plinthosols occur mainly in the moist tropical regions in low-lying positions where iron from the soil and adjacent uplands is accumulating.
Characteristics
Soils having either a petroplinthic horizon within 50 cm from the soil surface, or a plinthic horizon which either starts within 50 cm from the soil surface, or within 100 cm from the soil surface if it underlies an albic horizon or a horizon with stagnic properties.
Reference soil NG013: Plinthosols
Brief description of the profile: Moderately deep, somewhat poorly drained (strong) brown sandy (clay) loam underlain by fairly hard plinthite from 88 cm downwards; horizontation is gradual, structural development is weak and confined to the upper part of the solum. Parent material: Metamorphosed granite from basement complex. Vegetation: Open savanna woodland with Burkea afrikana, Detarium microcarpum, Butyrospermum paradoxum, Gardenia, Terminalia avicennoides. Additional notes on profile description: B3: Red and black mottles. Climate data source: Agroclimatological data Africa 1, FAO. Rome 1984.