Urban agriculture: The potential and challenges of producing food in cities

IN MANY CITIES around the world, patrons of high-end restaurants want quality food that is flavorful and fresh. To satisfy their guests, chefs are looking closer and closer to home – to locally grown produce from neighboring farms or even from their own, restaurant-owned gardens.

“You can’t find fresher food anywhere,” says Sam Wortman, assistant professor at University of Illinois at Urbana-Champaign. “Chefs are literally picking produce the same day they’re cooking it in the restaurants.”

As the concept of local food and urban gardening gains popularity, urban agriculture, with its benefits and obstacles, is coming to many cities. The issues surrounding food production in urban areas are outlined in a paper* recently published by Wortman and Sarah Taylor Lovell in the September-October issue of The Journal of Environmental Quality.

The benefits of urban agriculture are many. Urban gardens are often built on previously unused lots, increasing the beauty and value of the neighborhood. They provide recreation opportunities and a social network for the gardeners involved. Urban food production also means that healthy, fresh produce is readily available to city dwellers.

In light of the benefits, urban gardens are popping up across the nation. But the challenges that organizers and growers face must be understood and addressed if urban gardens are to become widespread and even profitable. Several obstacles face planners and growers including soil contaminants, water availability, and changes in climate and atmospheric conditions.

Several contaminants can be found in urban soils, and lead is the most prevalent. While there is concern about plants taking up lead from soils, research suggests that they actually take up very little. “Even in roots, there is still a relatively small amount of lead compared to, for example, what we’re exposed to from drinking water,” says Wortman.

Direct ingestion of soil containing lead is a bigger threat than plant uptake. Soils can be directly ingested when children play in and eat soil, soil adheres to crops after they’re harvested, or soil particles blow in the air. Practices such as washing food well before eating and covering soils with mulch can help decrease these risks.

An experimental site located along an urban to rural gradient in the Chicago, Illinois metro region Photo courtesy of Sam Wortman

Finding reliable and safe water sources can be difficult for urban farmers. Technologies such as drip irrigation that precisely deliver water where and when it’s needed can help conserve water. Reusing rainwater and wastewater can provide additional water, but those sources must be monitored for contaminants, and perhaps treated.

Changes in atmospheric and climate conditions in cities compared to rural areas can also be obstacles for urban growers. For example, temperatures and vapor pressure deficits (the difference between saturated and actual vapor pressure at a specific temperature) are often higher in cities. Extreme temperatures during the day and higher nighttime temperatures can inhibit photosynthesis in plants and decrease yields. Likewise, when vapor pressure deficits are higher, plants have to use more water creatingAir Max 90 Check In