Pursuing plant and animal production activities in urban environments. The agricultural activities could include such things as growing fruit tree along roadsides, creating a plant nursery in a vacant lot, a tree orchard on a steep slope unsuitable for housing, vegetables and chickens in backyards and on rooftops, community gardens, growing cash crops on the vacant grounds of an airport, a poultry farms on the city fringe, fish farming in rivers and sewage lagoons.
The division of global and inter-regional programmes of the UNDP began promoting urban agriculture in 1991, leading to the formation of the Urban Agriculture Network (based in Washington, DC).
Ninety percent of urban vegetable supply in China is produced in the cities. Calcutta has the world's largest sewage fed fisheries; also vegetable production using organic compost based of urban solid waste.
In Birmingham, UK, there is an innovative urban land-use and food production scheme called Ashram Acres. The project makes use of local skills to utilize derelict gardens, clearing them and making them productive. Another aim is to provide a meeting place for people who vary widely in age, race and background. High unemployment in the mainly Asia and East Indian community led to an interest in the cultivation of vegetable crops such as okra, cucumber, karella and coriander. Animals are also kept, goats providing milk and cheese. Hundreds of people are now involved in the project and derive both therapeutic and economic value from being able to produce fruit and vegetables not normally grown in the UK. "Members" pay a nominal amount to work on the project and are entitled to take produce home. The vegetables are grown organically in raised compost beds under cheaply-made polythene greenhouses, avoiding any contamination by lead in the soil and air. The huge success of the project has led Birmingham Council to make available to the community a larger one-acre site outside the city.
Urban agriculture has the potential of providing nutritional and food supply, income generation and enterprise development, land and waste management and contributes greatly to the sustainable environment of cities.