Response of plant growth to removal of surface soil of the rangelands of western Queensland.

Abstract

Pot and field studies were conducted to determine the potential effect on plant production of soil erosion in western Queensland. Soil from both the Mitchell grass (Astrebla spp.) and mulga (Acacin aneura) woodlands were used, but the studies concentrated on the latter soils. Test plants (oats, sorghum and pasture grass species) were grown in soil taken from sequential 5 cm intervals from the surface to 20 cm down the profile of each of the selected soils. Plants growing in subsurface soil, irrespective of soil type or history, were less productive than those growing on surface soil. This was attributed in part to reduced soil fertility and a difference in soil pH. Buffel grass (Cenchrur ciliaris), a species which has some use as an improved pasture in these rangelands, would be seriously disadvantaged on eroded soils. It is concluded that erosion of surface soil on these landscapes should be minimized by conserving ground cover.