"Sustainability rests on the principle that we must meet the needs of the present without compromising the ability of future generations to meet their own needs."--UC Sustainable Agriculture Research and Education Program http://www.sarep.ucdavis.edu/Concept.htm
"Sustainable agriculture integrates three main goals: environmental stewardship, farm profitability, and prosperous farming communities."
--Wikipedia, http://en.wikipedia.org/wiki/Sustainable_agriculture
"Bill Mollison was born in 1928 and has been called the 'father of permaculture', an integrated system of design encompassing not only agriculture, horticulture, architecture and ecology but also money management, land access strategies and legal systems for businesses and communities. The aims to create systems that provide for their own needs, do not pollute and are sustainable. Conservation of soil, water and energy are central issues to permaculture, as are stability and diversity."--http://www.rightlivelihood.org/mollison.html