The Potential of Some Mechanical Treatments for Rehabilitating Arid Rangelands I. Within-Site Effects and Economic Returns.

Abstract

Attempts to rehabilitate degraded arid rangelands do not always succeed, and we perceived a need for some simple ecological indicators which would help determine whether mechanical intervention was likely to be useful. In this first of two papers, we largely focus on the effect of pitting and opposed discing, although we consider ripping and exclosure briefly, at 26 locations in central Australia. Pits and furrows successfully trapped erosion products and supported more basal cover and a greater number of plants than inter-furrow mounds or untreated areas. In addition, a number of soil variables were altered by the treatments. However, economic returns were unlikely to exceed outlays in most of the cases we considered. The best returns are predicted where degradation is minor, where livestock are of high quality and where landholders collect their own seed. Exclusion of grazing in the initial stages will enhance the amount of plant cover.