Urban agriculture, the practice of growing food on rooftops, in backyards and in community gardens, has been an increasing source of food in developing countries for the last half century. In recent years the practice also has become popular in America, especially in many post-industrial cities that have experienced decline as manufacturing businesses closed.

Despite the increase in food production within cities, citizens continue to depend on the importation of food to meet their daily basic needs. A new study from The Ohio State University, however, suggests that most modern cities have the potential to generate up to 100 percent of their current needs for produce and other items.

The study, “Can cities become self-reliant in food?,” conducted by Parwinder Grewal, professor of entomology and director of the Center for Urban Environment and Economic Development at Ohio State University, suggests that a city such as Cleveland, OH, could produce most of the food its citizens need.

Grewal determined that Cleveland has more than 3,000 acres of vacant lots that are the result of years of manufacturing job losses, the recent economic downturn and a high rate of home foreclosures. He also found 2,900 acres of flat rooftops.

"Cleveland is very progressive in urban agriculture, with more than 200 community gardens (about 50 acres) in existence and legislation that allows for beekeeping and the production of small livestock within the city," Grewal said. "While not trivial, current local food production only accounts for 1.7 percent ($1.5 million) of the $89 million Cleveland spends annually on fresh produce, and 0.1 percent of the city's total food and beverage expenditures. However, the potential for food self-reliance is significantly higher considering available space in the city."

Grewal says Cleveland annually spends about $115 million on fresh fruits and vegetables, poultry, eggs and honey, “most of which comes from somewhere else -- California, Mexico, South America, even as far away as China and Thailand. Our study indicates that the city can prevent economic leakage anywhere from $27 million to $115 million annually by increasing its production of fresh produce, poultry and honey. This could boost the city's economy and lead to increased job creation."

Local food production has many other benefits, he says. Several studies have found that urban agriculture can help boost access to and consumption of fresh fruits and vegetables; cut obesity rates due to consumption of healthy food and increased physical activity; promote a sense of community and decrease crime activity; and raise property values as vacant lots are put to attractive and productive use.

Urban farming can also reduce human impact on the environment. Grewal said food in the U.S. travels an average of 1,500 miles from the farm to the consumer's plate, requiring large amounts of fuel and energy for transportation and refrigeration. Additionally, increasing green space in the city through farms and gardens can boost carbon storage in the soil, reduce problems associated with stormwater runoff, and curtail the urban heat island effect.

"Just like the organic food movement, where it was about five to six years ago, the local food movement is gaining a similar type of momentum right now, and every city has the potential to at least increase its local self-sufficiency and resilience by producing its own food. This is something we must move forward to, and the city of Cleveland is positively moving in that direction."