The phosphate content of Australian soils

Abstract

A map compiled from existing data is presented to show t>he recorded distribution of total phosphate in Australian soils. The generally low content for Australian soils is confirmed. From examination of the data, losses by leaching, especially under poor drainage conditions, appear to be the cause of the low values. The effect of plants is important but has received little attention. The distribution of the phosphate contents is shown to be related to parent material in soils on the eastern and southern fringes of the continent and in Tasmania, though leaching has also taken place. In the central part of the continent t)here is evidence that loss of phosphate took place earlier than the Pleistocene and probably during the mid and late Tertiary period of lateritization. Loss of phosphate during this prolonged period is considered the cause of the difference between Australian soils and the soils of the United States, which are generally younger, and presumably those of northern Europe.