Within the span of the last two or three generations, agriculture in the developed world has changed drastically. From single farm operations that used significant manual labour, we are now moving towards huge corporate farms that are highly mechanized food machines. The driving force is maximum economic production i.e. profit. Government policies, in particular export subsidies, favour monoculture production (e.g. wheat). While these changes have reduced the risk of farming and have generally put money into farmer's pockets, the social and environmental costs have been substantial. The degradation and loss of top soil, draining and contamination of aquifers and the virtual elimination of small towns and their way of life has had a noticeable impact on society. The alternative is to develop an agriculture system that is sustainable.

What is Sustainable Agriculture?

Sustainable agriculture is a concept that began to form in the 1970's following a number of publications that alerted the public to the dangers of modern farming systems (e.g. Rachel Carson's The Silent Spring that warned of toxic pesticides such as DDT). The public suddenly became aware of agriculture's impact on the environment and society. Now there is a growing movement among both scientists and the general public towards a goal of sustainable agriculture.

There is no generally accepted definition of "sustainable sgriculture" It is a concept that involves four main issues:

• Protect the Food Supply.- we must grow enough food for an exploding population. All nations should attempt to be self-sufficient in food. Food security allows nations to determine their own future rather than being subject to uncertain external forces by borrowing foreign currency to buy food.
• Protect the Environment - in our goal of producing food we should not sacrifice the environment. Agriculture is a significant contributor of greenhouse gases such as carbon dioxide and methane that contribute to global warming. Pesticides and fertilizers contaminate surface waters and aquifers. Farm machinery burns up fossil fuel. Monoculture reduces biodiversity and "mines" the soil. Certain wildlife species are destroyed.
• Protect the Economy - we can't continue to produce food with government subsidies and inefficient farming systems. The farmer must make a reasonable living. The true cost of production should be borne by all of society - including a good living for the farmer and farm labourers and taking into account the cost to the environment.
• Protect Society - social equity is a big issue in many parts of the world. Do we get rid of the small farmer to make big economic farms? Do we produce cheap food with the backs of cheap labour.