If you wondered why local food isn't as common any more, it's because the economics just don't work very well.
It doesn't take very much land to fill out the fruit needs of a population, which need about 50 acres to feed 10,000 people.
According to Dave Swenson, an economist at Iowa State University, food systems have comparable advantage, which means they're highly specialized. Iowa is good at growing corn, beans, and pork. While fruits and veggies may be better suited in a different state.
Sending food by rail or barge is cheaper than by a truck, so local food growers can be limited by their location, competition, and market.
Swenson says, "You don't just want to grow food and sell it to farmers' markets, you want to grow local foods and sell it to everybody. That means you have to get it into wholesale distribution systems. You have to tap into nearby markets. If you're in a reasonably small town, it doesn't take very much fruits and vegetables to to take care of everybody's needs. You've got to make enough money, you need to tap into being able to sell to a regional market"
Getting local food into the limelight is a priority, Swenson says the USDA is setting up ways to promote and fund local food, "Local foods is seen as one of the opportunities for stabilizing communities and reintroducing people to the sources of their food. So there are all kinds of reasons for promoting local foods."