On top of pavilion 6 of the Paris Expo, vegetables and fruit are grown on a scale that is most certainly impressive. It will the world’s largest urban roof farm when the entire space is optimised for farming. The brand new building in Paris’ 15 arrondissement is used for exhibitions and conventions all year long but visitors are utterly unaware of the plants slowly bearing fruit right above them. Strawberries, tomatoes and 33 other varieties of vegetables and fruit are grown here. And large it is, all 14.000 square meters of it. The equivalent of 2 football fields. The farm known as “Nature Urbaine” is the brain child of Pascal Hardy, president of Agropolis, an agricultural consultancy firm. The farm uses a technique called “aeroponics”, which means that the roots are not grown in soil but in the open air in a closed vertical column, where water combined with a nutrient solution is passed through and water spillage is reduced to a minimum and 90% recycled. One vertical column contains 59 plants, and to be able to cultivate the same amount of plants on the ground would require considerably more space and resources.Hardy, emphasises that the roof farms wil not be able to completely feed the entire Parisian population but estimates that it could take a market share of 5 to 10%. Apart from growing produce, Mr Hardy sees the concept as a way to educate the public and the need to produce locally without pesticides.