Our group has determined that a single vertical farm with an architectural footprint equivalent to a block from New York and a height of 30 floors could provide enough calories to meet the food needs of 50 000 people (2 000 cal / day / person), mainly by using technologies currently available, "Dickson Despommier, a researcher at the department of environmental health sciences at Columbia University. A tour by District to feed Parisians? A sacred break with agriculture known since the Neolithic period that can lend a smile. Especially since the system is still far from standing. The project Sky Farm, presented by the designer Gordon Graff could stand on 1.3 ha in Toronto, reaching the 230 meters on 58 floors and produce as much as a farm of 420 hectares. The arrangement of cultures is based on the needs of each in terms of sunshine, temperature ... At the top of the building, lettuce. A few floors below, carrots and green beans. By continuing the descent, we come to the spinach, then the peppers, wheat and potatoes. We do more than a dozen stories high, raising chickens for meat and for eggs starts, alongside tomatoes, zucchini and strawberries. Promise: food for 35 000 people. Other similar projects describe more precisely energies implemented, the flow of water, air ... Most plans to take advantage of the altitude to put two wind turbines on the roof. One provides power from the site, the other takes care of pumping rainwater. Some go further by playing on the slight difference in pressure between the foot and summit of the building to ensure the flow of air ...

The big economic question
But these farms vertical-shaped skyscraper that will exist if they manage to operate a vase almost ended by imitating ecological processes; ie recycling everything that is organic, recycled water "already used "(Waste of humans and animals), and regeneration of drinking water, while proving economically viable. That is why some are considering adding a few crops medical purpose and high value-added in that confined space. Finally we are only ideas on paper. Car considering the price per square foot in Paris, Lyon or New York and the housing shortage, replace human beings with potatoes to 5000 euro m2 seems a little complicated when these prices rather evoke a hectare in the spirit of farmers ...
However, researchers do not discourage work and the organization vertical cropping systems to allow each floor to take advantage of other levels to obtain optimal conditions. Sugarcane with a tropical climate with beet production or cold? This is how researchers and architects wonder together. For corn, the question does not arise. It must, simply because of productivity and variety of opportunities that we talk about food or energy, even genetically modified plants for the production of medicines. Rice also figure prominently, grown in hydroponics on the model of a rice groundwater which would open its doors in Japan.
Main advantages: the recycling of fertilizer and the promise of four harvests annually. As the vegetables used to greenhouse production, few constraints, if not the cost of production may oppose a vertical agriculture.