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Urban farmers on top of the world

Look up! There could be vegetables above you. Lufa Farms

With 87% of the Australian population living in urban areas, Australia is considered a highly urbanised country. Feeding all these people is becoming more fraught, but city buildings could be part of the solution.

Population growth is particularly significant in the major city areas, which are already home to 64% of the population.

Feeding large urban centres with sufficient and nutritious food is a challenge that Australia and many other countries have to face. Although the Federal government considers that “Australia is sheltered from immediate concerns about food shortages”, recent research studies tend to tell us otherwise.

Don’t be complacent about Australian food security

According to a University of Melbourne study, if we keep reallocating agricultural land to urban use (our “business as usual” model), Australia will have insufficient fruits and vegetables.

According to a report prepared by the NSW Department of Planning, in 2006 there were about 2,600 farms covering 104,000 hectares in the Sydney basin. By 2008, the numbers had dropped to 2,200 farms and 82,000 hectares. This is a drop of 15% in the number of Sydney farms and a 20% loss of arable land in just two years.

Sydney, like many other large cities, is under threat of losing agricultural industries, most notably food producing ones. Decades of urban development on the city fringes is gradually eroding agricultural activities in the surrounding basin.

When transporting food from far away sources will no longer be a viable option, retaining local food production will become vital to the sustainable future of our cities.

The new city farmers

When a Canadian company started selling fresh organic produce from its rooftop greenhouse in Montreal last April, it signalled what could be the beginning of a new urban farming revolution.

This farm concept is a very recent initiative from a young team of entrepreneurs from Montreal. They believe that rooftop greenhouses are a way to reclaim arable land from the city while contributing to its food security.

Their first greenhouse, using hydroponic cultivation, is on the roof of a 31,000 sq ft office building in central Montreal.

The capital costs to set up a rooftop farm are higher than conventional land farming (from $1 million to $2 million to find the building and set up the greenhouse). But operating costs are substantially lower and productivity much higher than conventional farming.

The creativity of the project resides in the idea of multiple growing climates within the greenhouse. The environmentally controlled facility offers hot areas for some vegetables, cooler areas for others, and even some “micro-climates” within each area.

Under the roof of the greenhouse, about 25 different varieties of vegetables are grown (GM crops are a no-go for this farm project) alongside a good variety of herbs.

Rainwater is captured and reticulated throughout the greenhouse in a closed-circuit loop. No irrigation water is discharged from the farm into the public wastewater system.

Cheaper to run than a conventional farm

Energy management has been integrated into the project. The greenhouse derives its energy supply from the heat produced by the building, and uses fully automated energy curtains preventing heat losses under cold weather conditions.

The rooftop farmers claim that their growing techniques use half the energy required by conventional growing methods.

The farmers decided not to use any chemical or synthetic pesticide. Instead, the farm opted for bio-control techniques, using micro-wasps or ladybugs to keep pests away from the crops.

The farm sells its products to the local community. This considerably reduces the food miles associated with distributing food. With a weekly production capacity to supply about 2,000 people, the facility yields as much produce as a conventional farm ten times its size.

Other models of urban farming

Pioneered by Professor Dickson Despommier from Columbia University, the vertical farm is another urban farm concept. These farms are housed in high rise buildings, away from droughts, floods and pests. They minimise the need for heavy machinery and transportation.

North America appears to be leading the way in rooftop farming. Already Bright Farms, a US consulting firm, has developed a business model around the concept of rooftop farming. Major American supermarket chains have already signed up to build and operate rooftop farms under this business model.

While setting up new urban farms in newer cities may be somewhat easier, integrating farms into old cities is one of the obstacles that architects and urban planners will have to face. Obtaining permits and resolving zoning issues will definitely require co-operation and shared vision from local authorities.

The future food supply system will need to be resilient in the face of uncertainty, be sustainable while offering healthy food at low social and environmental costs, and be competitive while meeting consumer expectations.

Can urban farming be part of this future? It is perhaps a little too early to predict, but clearly the prospect of a direct-to-consumer model should attract further community and business attention.

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