Definitions of sustainable agriculture are generally concerned with the need for agricultural practices to be economically viable, to meet human needs for food, to be environmentally positive, and to be concerned with quality of life. Since these objectives can be achieved in a number of different ways, sustainable agriculture is not linked to any particular technological practice.
Since World War II, agricultural production systems and food consumption patterns have undergone astonishing changes. Agricultural research has expanded the productive capacity of the world's farms tremendously, but this expansion has raised questions about the sustainability of modern practices about the criteria for judging risks and benefits of chemical and biological technologies, about the poor's entitlement to food production and safety in developing countries, and about who will farm in the future and how. The Agriculture, Food and Human Values Society is an organization of professionals dedicated to an open and free discussion of these and other related issues, and to an understanding of the values that underlie alternative visions of the food and agricultural systems.
This strategy features in the framework of Agenda 21 as formulated at UNCED (Rio de Janeiro, 1992), now coordinated by the United Nations Commission on Sustainable Development and implemented through national and local authorities. Agenda 21 recommends promoting social and economic research and policies that encourage development of sustainable agriculture, particularly in fragile ecosystems and densely populated areas.
An examination of traditional agriculture of the Jiaxing region of Eastern China in the seventeenth century shows the sustainable incorporation of silk, mulberry, livestock, fishing, and cereal crop production with little or no fossil fuel use.