Urban agriculture - where's the evidence?

Creative Commons Image: City Farm in Chicago, US

One potential way to combat the obesity epidemic and environmental degradation all in the same go is urban agriculture. I’ve been thinking a lot about this lately, wondering if it is feasible in climates like New York City and Toronto, if it can actually generate enough food to continuously feed a city, and of course, also improve diet quality at a population-level.

Urban agriculture refers to agricultural practices (usually intensive) within and around cities that compete for resources such as land, water, energy, and labour – but produce food, plant and animal-based pharmaceuticals, fibre, and fuel that benefit the local population (crops and animal husbandry included).  This can occur at the micro and meso scales of cities – e.g. using vacant lots, backyards, street verges, green roofs and walls, balconies, community gardens, urban parks, and individual collective garden allotments. Larger scale practices can include commercial farms, nurseries, and greenhouses, which would likely operate in peri-urban areas and be private/corporate, for-profit entities.

There are a number of other potential benefits for UA, aside from food, food security, and pollution/land degradation that I hadn’t initially thought about. These include: 

• Employment and income
• Personal skill development
• Social interaction/community or social capital-building
• Increased well-being
• Highest productive use of land (with respect to vacant lots)
• Diversified industry base
• Light, odour, and noise abatement/absorption 

I was surprised to read in a recent journal article that in developed countries like Australia, UA is responsible for 15% of state vegetable and fruit production. And that in Sydney, UA accounts for 1% of land area but contributes $1 billion in agriculture produce.  Those are interesting numbers, but I still feel skeptical; this is Australia after all, where temperatures rarely fall below freezing. And I imagine that most of this occurs at the macro, not the micro or meso scales.     

Most research on UA in terms of any type of outcome, not just health (e.g. environmental, social, and economic) has been in the form of case studies, with no real quantification of its benefits. It is difficult to build an argument for this practice with no hard evidence. At the same time, it has the potential to positively affect many different aspects of society, not just health. For this reason, I think UA is worthwhile.

I don’t, on the other hand, believe that farming at the micro and meso scales of cities (involving individuals and communities), especially in northern North America, can continuously feed local residents. Farming is time-intensive, and requires certain knowledge and skills. And to feed families year-round in North America, would require up-front investment for equipment like greenhouses. This is not compatible in a culture that breeds convenience and instant gratification, where for example, we don’t seem to have enough time to clean out reusable containers for our drinks, so instead buy crates of water bottled in plastic that can be thrown out or recycled.       

This may be different if UA at the micro/meso level is a social business, or a private/corporate entity. An example is the Science Barge in New York City, a 1300-square-foot greenhouse that floats on the Hudson River. It is a sustainable urban farm powered by solar, wind, and biofuel and irrigated by rainwater and purified river water. Fresh fruits and vegetables are grown using recirculating hydroponics and aquaponics. And surprisingly, despite floating on the river, is a prototype for a sustainable roof-top garden (more information on the Science Barge can be found here).  

Another example is Gotham Greens, a roof-top greenhouse in Brooklyn, NY that grows vegetables and herbs for local restaurants and retailers using sustainable methods. They expect to produce 80 tons of produce yearly, and employ residents in nearby communities.

Gotham Greens greenhouses

Macro-level UA in urban fringes using sustainable methods has potential, but right now is often more costly or harder to access than buying produce at supermarkets like Loblaws or Metro. Government policies (e.g. zoning) and community initiatives that support local farms will be needed to make buying local economically feasible and physically accessible to everyone. An example of this support is Equiterre, a Montreal-based organization that maintains a directory of Community Supported Agriculture (CSA) farms that must be local and organic, serving primarily low-income sharers (clients that share the risk of farming). The organization connects potential sharers with CSA farms, and coordinates drop-off points that increase accessibility for sharers, while at the same time minimizing transport time and cost to the farms. CSA produce prices are cheaper than what you would find in a supermarket, and the average farm is family run and has between 30-80 sharers.       

In terms of improving diet quality, many questions about UA in developed countries remain – can individuals and communities do it to feed themselves year-round? My guess is no. Is it economically feasible for social businesses, and for-profit private/corporate entities in urban and peri-urban areas? If so, will it be socially equitable and improve diet quality at the population-level? Given UA’s potential to benefit many different areas of society, I believe it is a worthwhile pursuit irrespective of scientific evidence. That being said, if further investment (time, money, policies, etc,) is to be made in UA, rigourous trans-disciplinary studies need to be conducted to quantify its benefits.               

Pearson, L., Pearson, L., & Pearson, C. (2010). Sustainable urban agriculture: stocktake and opportunities International Journal of Agricultural Sustainability, 8 (1), 7-19 DOI: 10.3763/ijas.2009.0468