Everybody likes the taste of organic, farm-fresh food, but in dense urban areas, large-scale agriculture isn't really an option. A Dutch design firm has come up with a concept for a rooftop greenhouse ecosystem that produces food so efficiently that installing them on top of buildings in NYC could feed the majority of people living there.
The secret to the Polydome, as it's called, is utilizing as much area as possible, as efficiently as possible. Part of this overall philosophy includes making a conscious decision to combine plants and animals that can create a balanced, largely self-maintaining ecosystem without needing fertilizers or pesticides. Yes, there are animals involved, too: Polydomes can sustain chickens, fish (in artificial ponds), and even bees to make honey. It's even possible to make Polydomes zero-waste, since plant waste gets mulched or fed to fish, while animal waste fertilizes the plants.
Crops inside the Polydomes are arranged in modular "clusters" that can be mixed and matched depending on what you like to eat. Shade plants are mixed in with plants that prefer full sun, and hydroponics hang from the ceiling while mushrooms grow below. Most of what grows is perennial, meaning that you don't need to worry about replanting, and at peak output, a Polydome can produce a staggering 15 pounds of food per square foot, which includes fruits, vegetables, eggs, and fish.
A single Polydome is designed to last 30 years, and it's good for more than snacking on: many of the crops (like herbs, mushrooms, and berries) are relatively high value especially when fresh, making a Polydome a viable commercial microfarm.
While this is just a concept, the idea has been very carefully considered, and the Dutch design firm Except has released a crazily comprehensive 80 page research report under a Creative Commons license, hoping that someone will take this on and make something out of it. See how they think a finished Polydome might look, in the gallery below.