Abandoned, vacant plots in the city of Baltimore, Maryland abound. Now some of them are being used to grow food!
Big City Farms, the first company to sign a lease to grow food on abandoned land in Baltimore, has a great model for inner city food production. They are setting up shop on asphalt, with a few inches of compost, in large hoop houses.
Not unlike Detroit, Baltimore lost about 1/3 its population from its industrial high point during the post war peak. There are entire pockets of inner city blight where this kind of format for urban farming can take shape.
The city of Baltimore hopes to lease out 8 hectares of vacant land to urban farmers in the next 5 years.
What a promising development! You don't even need farmland, just space to put compost and hoop houses to work!