So far the grey areas of sustainable development have been considered, which have partly influenced the philosophy of sustainable agriculture [Reeve 1990]. Sustainable development has influenced the direction of sustainable agriculture [eds Edwards et al. 1990] and has opened up the debate away from the traditional approach to economics and has raised issues that involve ethics, biodiversity, ecology and the global dimension. Before considering the issues involving sustainable agriculture it is necessary to identify the meaning of agriculture within today's current understanding. It is significant that the meaning and interpretation of the word agri-culture has changed from the interpretation 'to tend the land', which has connotations of stewardship and an ethical duty of care, to a modern interpretation which has a more artificial and financial setting as the word agriculture is being replaced by agri-business [Sydney University, 1995]. The meaning of the word agriculture is derived from the Late Latin word agricultura. Agri meaning the land and cultura meaning to cultivate or tend. The word 'culture' is Middle French and again comes from the Latin Cultura which is borrowed from the Latin word colere meaning to till or cherish [Barnhart et al. 1977].

It would appear that there has been a significant change in the use of the language, which can be traced back to the meaning of the word [agri-] culture. Liebig [1847] refers to "the art of culture" and "the method of culture." In these examples culture is used in the sense of good husbandry: the selection of good seed and correct tillage operations etc.. Burgess uses the term culture as a heading, "The culture of our Farm Crops" [Burgess, 1893, p.105] and implies that agriculture is the cultivation of the soil, but he implies it is more than just the physical act of ploughing. Cultivation is used for the tending of plants so that they may grow at their full capacity.

Over the past two hundred years the term 'culture', which has been superseded by the word cultivation, has been influenced by the word manure, so that its meaning has been altered. For example, Bailey [1906] states that "in a very important sense, tillage is manure" [Bailey, 1906, p.65] and Hendrick explains that "in its original use the word manuring meant the working or cultivation of the soil, but, while we can improve the soil by good cultivation, the term "manure" is now used to indicate substances which are added to the soil to improve its fertility, and thus enable it to grow better crops" [Hendrick, 1923, p.103]. Andrews [1853] identifies farm-yard manure, vegetable or green manures and Superphosphate of lime as a manure. Burgess [1893] identifies the use of artificial manuring as being not so much to manure the land as to feed the crop, for example with sulphate of ammonia and Thomas phosphate powder. Even as far back as the beginning of this century Bailey differentiated between livestock manure, soil amendment i.e. lime and chemical fertilisers such as superphosphate, and complete fertilisers [Bailey, 1906].

The impact of the change of meaning is reflected in a number of ways, for it is significant that today the root meaning of agri-culture i.e. 'to tend or cherish the land', has largely been lost. In addition the use of the word 'husbandry' has also lost favour. Symons [1972] is one of the few modern authors to use the term 'husbandry' in the sense of describing agriculture as man's husbandry of the land. Both these factors appear to reflect a philosophical move away from an ethical duty of care or entrusting responsibility for the land or, what Beatley [1994] describes, as the concept of stewardship.

An example of the change of meanings can also be seen in one of the more long established definitions of agriculture which was developed by Lawes in 1847 and slightly modified by Nicol.

Lawes' definition makes several assumptions in that the land has had some form of human intervention to produce more food, the land is not being degraded and is ongoing or sustainable. Lawes' English definition was published in the same year as Liebig's previously mentioned "the art of culture" in German literature. Both men were pioneers and actively interested in minerals and agriculture, yet the wording used by Lawes mentions artificial induction, which appears to reflect a move away from cherishing or tending the land and reflects the changing use of the word culture to cultivation-manure-fertiliser. Artificial induction also ties in with the use of artificial fertilisers that were first patented by Laws in 1843 [Russell, 1966]. In contrast, Nicol [1967] suggests that the use of the word 'artificial' is justified as production of food in agriculture is artificial, due to human management.

The study of agriculture is a wide and diverse subject and Tivy's [1990] modern definition of agriculture includes within its broad parameters the cultivation and/or the production of livestock products or crop plants. Spedding [1988], whose specialist interest is in agricultural systems, defines agriculture as: