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Characteristics of savanna soils

Information below is broken up into two tables: the first covers lateritic soils, clays and red/yellow earths. The second table looks at lithosols, earthy sands and alluvial soil.

	Lateritic soils	Clays	Red/yellow earths
Horizon Characteristics	- layers of iron or aluminium gravel - A horizon leached of nutrients - generally red/yellow claystone in B horizon	- uniform fine textured profile - self mulching on surface, forming layer of pods.	Red - distinguished by massive B horizon - three types: normal, lateritic (distinguished by horizon of ironstone nodules) and podzolic Yellow - massive and yellow in the B horizon - B horizon often characterised by iron/ laterite nodules
Structure/ Texture	- parent material tends to be old rocks	- relatively fertile - sometimes lacking in nitrogen - sticky and often hard to work when wet. Cultivation requires large and powerful machinery, so despite fertility are generally not cultivated - acidic in brigalow forests of eastern australia - hold water, and crack deeply in the dry	Red - low water-holding capacity -generally require heavy fertilization with phosphorous, nitrogen and trace elements - mildly acidic predominantly sandy textured Yellow - infertile - porous - generally associated with the presence of red earths - moderately permeable - low to very low nutrient status - acidic to neutral and yellow/ brown
Fertility	Very low	Relatively high	Moderate
Distribution	- scattered over much of the tropical savannas, esp. in high rainfall areas	- Mitchell grasslands - Barkly plains - Victoria River District - floodplains of Kakadu - areas adjacent to the Daly River, NT - Ord River in the Kimberleys	Red - scattered patches in Cape York and NE Qld - large areas around Katherine and the Daly River in the NT, and around Tenant Creek south of the Barkly tablelands Yellow - south of Charters Towers - large areas on west side of Cape York - Eastern parts of Arnhem land and Gove peninsula, NT - scattered occurrences in NT and Kimberley
Useful for	- bauxite/iron ore mining	- grazing - areas in Kimberley region used for irrigated rice, cotton	- cattle grazing of native grasses - peanuts and other crops around Katherine/ - cattle grazing - rarely cultivated

	Lithosols	Earthy sands	Alluvial
Horizon Characteristics	- uniform stony/gravelly throughout profile - lacking in soil horizon development - shallow - may have cover of gravel	- uniform sandy profile - ranging from deep to shallow - lacking in A2 horizon	- young soils which haven't had time for profile development - may have layers from deposition
Structure/ Texture	- often formed on remnants of deeply weathered laterite profiles - common on steep slopes and exposed hillcrests	- associated with old strongly weathered siliceous parent material - very low fertility - lacking in structural development - highly permeable though often overly impermeable rock	- associated with rivers, alluvial fans, flood plains - deposited by still or moving water
Fertility	Very low	Very low	Relatively high
Distribution	- plateau areas of the Kimberley - Much of the gulf region inside the NT border - plateau areas of arnhem land, and of Kakadu - scattered areas in mitchell grass - hills of the VRD - parts of NE Qld	- large areas in the NT, extending into Arnhem land - associated with low tablelands/ plateau remnants - around Borroloola	- large areas of the west side of Cape York - isolated patches around Darwin and Broome - base of the gulf region - south of Charters Towers
Useful for	- sporadic grazing of sparse native vegetation	- sparse grazing/ not used at all	- horticulture in SE sectors - grazing where irrigation is not possible.