In urban centres where the land has been used for buildings and other infrastructure there is little room for production farms, so how do we teach children about farming? Well, we can use hydroponics to grow plants and help people understand why plants and food are so great.

A school in New York City has installed a hydroponic greenhouse that makes use of rainwater to grow plants for their school.

There’s no soil in a hydroponic greenhouse, which captures and recirculates rainwater to the roots of plants. In capable hands — though maybe not in 5-year-old hands — the 1,400-square-foot structure can produce up to 8,000 pounds of vegetables every year. It is an experiment in environmental education its founders hope will be replicated in schools citywide.

Two mothers at the school, Sidsel Robards and Manuela Zamora, founded the greenhouse, inspired in 2008 by a trip to the Science Barge, a floating urban farm docked in Yonkers. They got New York Sun Works, the nonprofit green-design group that built the barge, interested enough to execute the greenhouse, a bright, open and wheelchair-accessible space, covered by glass and entered from the school’s third floor, that is essentially the Barge on a roof.

It includes a rainwater catchment system, a weather station, a sustainable air conditioner made of cardboard, a worm-composting center and solar panels. In the center of the room is a system resembling a plant-filled hot tub: an aquaponics system home to a community of tilapia, whose waste is converted into nitrate. The system loses water only when it evaporates to help cool plants, consuming only a tiny fraction of the water that a field of conventional dirt does.

“You basically can have this closed system, this symbiotic thing going on, where plants are eating food, creating waste, you’re converting it and then the plants are taking it up,” said Zak Adams, director of ecological design at BrightFarm Systems, which designed the greenhouse and the barge.

Read the full article at The New York Times.