Sustainable Agriculture definition:

Sustainable Agriculture refers to a production process that utilizes resources in a manner that reduces negative impact on the surroundings and ensures that such resources are available for use by future generations.

Also...

Sustainable agriculture is the practice of farming using principles of ecology, the study of relationships between organisms and their environment. It has been defined as "an integrated system of plant and animal production practices having a site-specific application that will last over the long term:

• Satisfy human food and fiber needs
• 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.”

Wikipedia: http://en.wikipedia.org/wiki/Sustainable_agriculture CC: BY SA