Soil Development in the Eastern Hardveld

Variations in the nature and properties of soils (pedodiversity) on the Late Neogene hilly dryland and Quaternary erosional and depositional surfaces of the Hardveld, spanning the south-eastern to south-central parts of Botswana are well established. Following the updated IUSS Working Group World Reference Base (WRB) soil classification system, this chapter discusses the major soils found on the eastern Hardveld of Botswana. Ten Reference Soil Groups develop on the Hardveld: Regosols, Arenosols, Luvisols, Lixisols, Cambisols, Calcisols, Vertisols, Leptosols, Planosols, and Acrisols. Dominant pedogenic processes in the area include salinization, calcification and decalcification, illuviation, eluviation and erosion. Interbedded fossil soils (palaeosols) within alluvial deposits found in the Hardveld are indicators of environmental and climate fluctuations in the region. The complex interplay of parent material and climate as key active factors, and organisms, topography and time as passive factors, through material fluxes such as addition, removal, transfer and transformation are fundamentally responsible for the formation of different soils found on the Hardveld.