The term "sustainable agriculture" aims to take into consideration how agricultural systems must act if they want to be a part of an economy with a sustainable step. Some of the factors that contribute to the sustainability of agriculture are under the control of farmers, as long as the collective decisions of all farmers affect the sustainability of the whole economy (Norman et al. 1997).
To develop a conceptual model of a system of sustainable agricultural production, it is necessary to take into consideration definition of "sustainable agriculture".
The American Society of Agronomy (1989) provides a detailed definition of sustainable agriculture:
"A sustainable agriculture is one that, over the long term, (1) enhances environmental quality and the resource base on which agriculture depends; (2) provides for basic human food and fiber needs; (3) is economically viable; (4) and enhances the quality of life for farmers and society as a whole."
Sustainable agriculture also was addressed by the United States Congress in 1990 Farm Bill:
“Sustainable agriculture means an integrated system of plant and animal production practices having a site-specific application that over the long term will:
• Satisfy human food and fiber needs.
• Enhance environmental quality and the natural resource base upon which the agricultural economy depends.
• Make the most efficient use of non-renewable resources and on-farm resources and integrate, where appropriate, natural biological cycles and controls.
• Sustain the economic viability of farm operations.
• Enhance the quality of life for farmers and society as a whole.”
Theoretically, what should be emphasized is that sustainability requires that farmers when they take any decisions to consider the impact on welfare, including environmental, social/institutional and economic aspects for the actual and the future generations, also for all people (Norman et al., 1997).
In this teaching resource, the fieldwork teaching method will be used, as a method that involves the collection of information outside the classroom. This method will give the opportunity to the students to see closely the problems that agriculture is facing, and to understand what should be done to develop it in a sustainable manner. For this reason, it is necessary to define carefully the farms which will be visited by the students. All collected information, will be discussed in small groups through the World café method. These are two main teaching methods that will be used in this teaching resource.