Development and distribution of soils in the Merredin area, Western Australia

Abstract

The soil pattern in the Merredin district of Western Australia is closely related to a number of readily recognizable landscape features. An understanding of these relationships is proving useful in broad-scale mapping in semi-arid Western Australia and the units so obtained can be readily subdivided for more detailed mapping. Soil and topographic relationships of the five surfaces recognized are described in detail. These are an expression of erosional modifications of a mature Tertiary landscape resulting from changes in landscape stability. Deep lateritic weathering has influenced the chemistry and morphology of large areas of soils. Smaller areas of soils are developed from less weathered material exposed by complete removal of the lateritic profile, and from lake parna resulting from wind deflation of salinized alluvial sediments. The physical and chemical properties of samples from representative soils are summarized and discussed with reference to profiles which are arranged in groups on the basis of origin of parent material.

Legacy of Land-Use Evident in Soils of Western Australia’s Wheatbelt

“…The increase in pH may reflect increased base cation concentrations in the grass litter (Ehrenfeld, 2003). The ele- vated potassium levels in the Letchford old-field are consistent with this explanation, though they are more likely a result of the relatively high percentage clay content of this soil (Bettenay and Hingston, 1964). Altered pH can affect plant species diversity (Roem and Berendse, 2000) though the values for the Letchford old-field are within the range expected for uncultivated soils of that soil type and depth (i.e.…”

“…Our study sites are located on one or more of three landform-soil units described by Bettenay and Hingston (1964) and mapped by McArthur (1992McArthur ( , 1993. The Booraan unit is located on the slope of the catena where shallow (30-40 cm) sands or sandy loams have developed over the weathered mottled and pallid zone material (Natric Haploxeralf; Plinthic Lixisol).…”

Aeolian influences on the soils and landforms of the southern Yilgarn Craton of semi-arid, southwestern Australia

“…Deep sands often occur on the lee-slope of lunettes (''l''). Bettenay and Hingston, 1964), however, this may be a function of the mapping scale (f 1:300 000).…”

“…These include (a) formation in situ where they represent the remnants of the surface horizons of lateritised profiles (Prider, 1966), (b) formation on colluvium eroded from remnant ferricrete horizons and deposited down-slope (Mulcahy, 1960;Bettenay and Hingston, 1964;Brewer and Bettenay, 1973) or (c) formation on aeolian deposits Glassford and Semeniuk, 1995) with the soils being remnants following the passage of sand from the desert to the west, although this view is controversial (Wyrwoll and King, 1984).…”

“…In the Belka Valley near Merredin, for example, it has been estimated that around 24% of the landscape is comprised of such soils (Bettenay and Hingston, 1964). Consequently, identification of an aeolian origin for such soils in the study area may provide insights into the origin of the soils of a much wider area.…”