The idea of returning Detroit to farm land is an interesting idea that was recently covered in New Geography(DETROIT: URBAN LABORATORY AND THE NEW AMERICAN FRONTIER, Nov. 4) and New York Times(Plowing Detroit Into Farmland blog post Nov. 9 based on New Geography article).
The New Geography article reviews the size and scale of Detroit in comparison to other cities and the extent of urban decay since the 1950′s and that Detroit could become farmland.
In my opinion, Detroit could become a city of urban agriculture; it has the land, water & infrastructure(roads, rail) and lots of deserted industrial space that could be converted to markets and storage/logistics. However it would require a either a grass roots movement which gets financial backing (after initial results) from investors or a federal incentive as the city of Detroit is shrinking and resources are already stretched.
Urban agriculture could supply the people of Detroit and other cities in region with food. Large areas of housing could be converted to open fields where the blocks are large or rows of green houses where the blocks are narrow. The agricultural areas could also grow crops for ethanol(although resource intensive) to supply raw materials for fuel(refined in Detroit) for the farm machinery and cars.
Urban agriculture combined with alternative energy such as wind and solar could convert Detroit from a city to a urban core with villages (see New Geography for diagram). The city could become self-sufficient and a possible testing ground for urban design that could be used for other North Americans cities going through the same changes in size and urban form.
New Orleans is currently a hot bed for Urban Design experiments for the South, which came about from a natural disaster maybe Detroit can come back as the hot bed of Urban Design for Northern climates.
Detroit has the opportunity and basic resources but does it have the will to change?