This means building a farm in _the space of a highrise office block - A highrise farm.
By using mechanised or robotic farm systems, a food producing farm need no longer be built on a large flat area of land. It could be built in vertical format. This also make pollution filtering easy - as all the water run-off can be collected at the bottom of the wall and filtered there.
One wall contains a fertilizer reinforced with a mesh of sorts to stop it fragmenting. The other has high intensity lamps. The fact that plants are phototropic means they will grow towards this (once past the geotropic seedling phase). The robots will run on XY style gantries to tend and harvest the plants - with misters, clippers and hoppers for gathering produce. As robots are still not amazingly effective at produce QA - this would still be a human effort, in another part of the installation.
Non-green plants (ie fungi) are not phototropic, and many fungi can be grown at any angle(ie not particularly geotreopic either).
Because of the ease of an XY bot in this format, the massive reduction in land usage and the ease of filtering pollution, you could build these in inner city areas, at a massive reduction in cost. It would also reduce shipping by large amounts.
Robot seeders will be a tool for the XY bots which pierces the soil/fertilizer, and deposits a seed.
Vegetable matter waste products will be composted (the gases captured), and mixed with fertilizers for use back in the installation.
I hope to see these in London some day.
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