Growing Cities

Urban agriculture, the practice of growing food on rooftops, in backyards and in community gardens, has been an increasing source of food. In recent years the practice also has become popular in many post-industrial cities especially those that have experienced decline as manufacturing businesses closed (the UK government recently had to do a U-turn on proposals to remove requirement for local authorities to set aside land for allotments.) These growing sanctuaries built in abandoned lots, between buildings, and along streets and sidewalks, are springing up. Local residents become agents of production and get involved directly with their neighbors and generate their own food source. As a result orchards, greenhouses, and markets are on the rise.

Despite the increase in food production within cities, urban dwellers 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.

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."...current local food production only accounts for 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.

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.

The Chicago City Council approved a zoning code amendment allowing for more widespread urban agriculture. The zoning code has expanded the size of community gardens to 25,000 feet, thus accommodating commercial farms within city limits. The ordinance also trims some of the red tape both farms and gardens face. The new rules will also allow for limited produce sales in residential areas, relax parking and fencing rules for larger urban farms and allow for aquaponics -- sustainable, symbiotic food production systems -- to be used. "The City worked with its sister agencies, urban agriculture experts and community members in an effort to help strengthen community ties and turn available empty lots into viable, productive urban green spaces," the mayor explained. The city of Chicago produces over 15,000 tons of urban waste each day, all of which could be used to create moist soil and robust plants.

A new report from the Urban Design Lab at Columbia University’s Earth Institute explored New Yorks urban agriculture potential. It identified nearly 5,000 acres of vacant land that would be suitable for farming throughout the city’s five boroughs. That’s about six times the area of Central Park. All that without including 1,000 acres of NYC Housing Authority green space and other underutilized spaces that could be turned into farms. The report admits that urban agriculture alone wouldn’t be enough to totally feed the city.

A company has devised means by which transform shipping containers into hydroponics farms that can each produce one acre worth of crops. Using LED lighting, no pesticides, and less water than traditional farms, six containers can supply about 200 pounds of leafy greens a week. 90% of the nation's leafy greens come from California, meaning they have to get shipped to the rest of the country. That method uses up a great deal of resources and adds to the nation's overall pollution levels due to trucking and refrigeration. Stacked hydroponic containers in unused urban areas can deliver fresh, no pesticide vegetables to local markets and restaurants quicker and cleaner.The containers are doing this by taking advantage of the latest in technology and efficiency. Six containers can be maintained by just one employee who can monitor conditions inside via iPhone. LED lights can also be set to grow brighter and dimmer throughout the day to mimic the sun's natural cycle.

Growing Power is an active farm , has been producing vegetables and fruit in greenhouses along with bees, ducks, goats, and turkeys on its nearby regional rural farms, composting more than 6 million pounds of food waste each year. Fresh produce, free range eggs, grass-fed beef, and honey are benefits of this integral part of the composting process. The highlight of this urban agricultural project is an aquaponics system where tilapia and yellow perch are raised in 10,000 gallon tanks. This system is integrated with the food production operation where the water from the tanks flows into a gravel bed, breaking down nitrogen and supporting a crop of watercress, increasing the filtration process. The nutrient-rich water is then pumped to overhead beds growing tomatoes and greens. The plants extract the nutrients and worms in the soil consume bacteria. The re-circulating fresh water is pumped back into the fish tanks where the process starts all over again.

Dickson Despommier, author of the "Vertical Farm”, says "Indoor farming in a greenhouse means you don't have seasons, you can grow them year round, you won't have crops lost because of weather, you can screen out insect pests, you can even keep out a lot plant diseases that are microbial by simply positively pressuring the green house," Despommier said, adding that adding that switching to vertical farming reduces water usage by 70 to 95 percent. Despommier’s vision relies on two parallel developments. One is a stand-alone building to raise crops, the other is more rooftop gardens