High Soil Nitrate-levels in Patterned Saltbush Communities

Abstract

ONE of the principal native sheep-grazing pastures in the Australian arid-zone¹ is that represented by shrub communities of perennial species of the genus Atriplex, particularly the bladder saltbush A. vesicaria. Pastures dominated by this species, together with degenerate types resulting from overgrazing of the original cover, are most extensive in South Australia but occur widely in western New South Wales and in south-west Queensland. Over a high proportion of this total area the saltbush communities are associated with fine-textured, saline soils the surfaces of which show strong gilgai development. Of these soils those included in the stony table-land and solonetz groups² are of the greatest extent.