몬트리올에 두 번째로 문을 연 상업용 옥상농장

A few years ago, the idea of a large-scale commercial urban farms capable of providing locally-produced food seemed impossible. But in 2011, the world's first commercial rooftop urban farm opened in Montreal, Canada, and now, aiming to expand its direct-to consumer business model, Lufa Farms is launching a second, larger operation this week in Laval, just north of the city.

Located on top of building that also houses a furniture retailer and other commercial tenants, the new greenhouse measures 43,000 square feet. Currently, the company harvests 1,000 to 1,500 pounds of food daily and delivers more than 2,500 baskets of produce per week to drop-off points all over the metropolitan area year-round, with the new farm boosting overall production to an extra 2,000 to 3,000 pounds of food per day. Basic baskets start at $30 per week.

Built in conjunction with the developer Groupe Montoni and Dutch greenhouse manufacturer KUBO, this latest greenhouse is made to be structurally lighter than the first, employing a "positive pressure" system which allows it to keep out insects and produce 30 percent more food per square meter than Lufa Farms' previous greenhouse, and with less energy inputs. In this second operation, the focus will be on tomatoes and eggplants -- veggies that are in high demand and require more particular conditions.

Similar to the first greenhouse, the second development uses a hydroponic system to produce vegetables, grown using coconut fiber bags, a lightweight substrate and nutrient-rich fluid, and is irrigated with water that is captured, filtered and recirculated for re-use. The greenhouse is heated with a natural gas system at night, in addition with shade curtains for heat retention, but its location on top of a heated building means that it needs only half of the energy per square foot to grow food compared to a conventional farm on the ground, and without the use of pesticides and herbicides.

Consistent with Lufa Farms' focus on specialized agricultural technologies, everyday technical operations, climate control and irrigation will be regulated by custom-developed iPad applications. (Images below are of Lufa Farms' first greenhouse on Montreal island.)

Founder Mohamed Hage spoke with TreeHugger about Lufa Farms' vision of sustainable urban farming where the cost of food and the technology required to grow it will be lowered and more easily implemented:

We’re at a stage now where we have two farms and we’re comfortable with the technology... and we are ready to roll out this concept. We are big believers that this will be the way cities will be designed. As we go from seven billion to nine billion, more people to feed with less land, less water, less resources, this is a solution that addresses all of that. You’re taking ignored spaces, you’re improving the building’s efficiency, you’re growing with less land, less energy, you have practically no transportation and no packaging, and no loss because you’re only harvesting what you need for the day, so it’s a very minimalist way of growing food.

In addition to growing more than 40 varieties of vegetables, Hage says that Lufa Farms has also partnered with 50 other local food growers to provide over 100 products ranging from breads, cheeses, flour and jams:

We decided to become a portal or an online farmer's market for everything that is locally and sustainably produced, from organic farmers to artisanal food-makers.

Hage explains that the goal is to help create self-sustaining cities that can feed themselves. According to their calculations, a city of 1.6 million like Montreal could be agriculturally self-sufficient if the roofs of 20 malls were converted over to growing food.

With future plans to supply local restaurants and to expand globally in cities like Boston, the Lufa Farms model is an intensive operation that seems quite different from the soil-based agriculture we are used to. But it could be the beginning of an urban farming renaissance: with the increasing cost of transporting food from far-flung places, and the required technology improving daily, producing locally-grown food in this fashion may very well be one viable way cities will be able to feed themselves sustainably and affordably.

For more information, you can visit Lufa Farms' website and Facebook page, or check out their TED talk.

http://www.treehugger.com/green-food/second-lufa-farms-rooftop-urban-farm-opens-laval-quebec-canada.html