A farm on top of a flat rooftop in Germany supplies locals and local restaurants with organic fresh fruit, vegetables and fish. A solution to eating locally and organically with limited dependency on water and soil. The system relies on aquaponic farming, an association between aquaculture and hydropony. The idea is to water out-of-soil products with water from fish farming. The phosphorus and nitrogen compounds rejected by the fish are used as a fertiliser for the plants.
Although the idea is simple, it is a complex system. Aquaponic farming is an ecosystem with three types of organisms - fish, plants and bacteria, which must cohabit. The aim is to find the right equilibrium between the fish population, the food made, the bacteria population, the farmed vegetation, and the given time.
Whilst Northern America and Australia are ahead on the subject, Europe has become interested, with Germany in the lead. The Apiva project in France aims to test this technique and see whether it could be transferred to horticulture.