This document considered the subject of sustainability, which is an inherently 'fuzzy' problem with innumberable grey areas due to the arbitrary and intangible nature of the term 'sustainable' [Campbell, 1994; eds Edwards et al. 1990; Reeve, 1990]. Definitions of sustainability have thus tended to define what is not sustainable agriculture instead of clarifying what is sustainable agriculture [Reeve, 1990]. Although there is general agreement about the necessity of sustainability there is disagreement over its interpretation and application in Western industrialised countries who consider sustainability from a short term economic paradigm [eds Edwards et al. 1990].

The defining of 'sustainability' is essential for any in depth study of sustainable agriculture [eds Edwards et al. 1990]. It involves complex issues such as timeframes, differing scales in space and levels of permanance [eds Edwards et al. 1990; Roberts, 1995; Campbell, 1994; Reeve, 1990] which has made this topic highly debateable. This author adopts the definition that sustainability is 'forever' [Kenney, 1989] and that its interpretation should be on a global dimension. This broad interpretation is necessary as if it was any narrower controversy would inevitably result as the rhetorical question could be asked, would research of three, ten, one hundred or even a thousand years be considered as a sustainable timeframe?

It has been suggested by Reeve [1992] that the modern usage of the term 'sustainable' has stemmed from 'sustainable development', which in turn has its foundations in modern environmentalism. The word 'sustainable' is of great environmentalist power [Rodale, 1990] and has come into popular use and as an umbrella term is applied to many situations [Reeve, 1992]. This author recognises that it is more difficult to prescribe the practices that will be sustainable in the future [Reeve, 1990]. Campbell [1991] suggests that if all resources in a system are considered, modern agricultural systems are not sustainable. His interpretation would appear to be valid. Hence, the use of the term 'relative sustainability' would be more appropriate when assessing seemingly non-sustainable systems.

The concept of sustainable development has played an important evolutionary role in the sustainable debate and became the catch cry in the eighties for the "Green" movement in Western societies [Tulloch, 1991]. Yet today there is growing cynicism as the term 'economic progress' and 'living standards' are being maintained by the rapid use of non-renewable resources and thus deprive future generations of these precious resources [Beatley, 1994; Fleay, 1995]. The scale of sustainability whether on farm, local or regional level all impacts on the global dimension as the the earth forms one large ecosystem. The global aspect of sustainability is a foundational principle of sustainable development [Bierbaum, 1991].

In assessing the relative sustainability of current agricultural production systems it is necessary to define 'sustainable agriculture', but again their are many interpretations to this ambiguous term due to a host of apparent conflicting ideas and heavily value laden concepts. The popularity of the term sustainable agriculture has lead to a broad interpretation of the meaning sustainable [Reeve, 1990]. Again the interpretation of sustainable agriculture as farming forever brings into question a broader consideration of what makes a agricultural system sustainable. Australian farmers are becoming more conscious of the term sustainable agriculture and are making a conscious effort to address this situation i.e. Land Care [Roberts, 1995]. As farmers' attitudes are changing so is their interpretation as to the meaning and relevance of sustainable agriculture [Roberts, 1995].