Two years ago we first covered Tokyo's underground farm; It is called Pasona O2 and was set up as a means of providing agricultural training to young people who are having trouble finding employment and middle-aged people in search of a second career. Of course, since we first posted the interest in local food has increased dramatically and there has been much more interest in urban farming. We also came upon some new information:
The Pasona Group has a traditional farm in Ogata, but they want the "freeters" (Japanese slackers who hop between part time jobs) to get a taste, so to speak. It also is open to middle-aged people in search of a second career. There are a thousand square metres (10,000 SF) growing 100 different kinds of produce.
"In the absence of sunlight, the plants are sustained by artificial light from light-emitting diodes, metal halide lamps, and high-pressure sodium vapor lamps. The temperature of the room is controlled by computer, and the vegetables are grown by a pesticide-free method in which fertilizer and carbon dioxide are delivered by spraying. Hydroponics, in which plants are grown in water and hardly any soil is used, is one of the methods of cultivation used in the facility."
Room 1 Flower field. White LEDs are used. Plant cultivation by RGB LED.
Metal halids spotlights are used.
Room 3 Shelf rice field. Metal halids lamps and high-pressure sodium lamps are used.
It explains that it is possible to do by three crops a year.
Room 4 Fruit/vegetable field. Cultivation of tomato by hydroponics.
3 wavelength, 5000 deg. K, High-frequency fluorescent lamp.
Room 6 Seedling room. Lettuces are being grown with fluorescent lamps.
2xFour steps cultivation bed.
It is all very energy-intensive; we would prefer to see more use of Parans type piped natural light or heliostats but this could be the start of a new underground movement.