http://theconversation.com/how-urban-farmers-are-learning-to-grow-food-without-soil-or-natural-light-88720

Growing food in cities became popular in Europe and North America during and immediately after World War II. Urban farming provided citizens with food, at a time when resources were desperately scarce. In the decades that followed, parcels of land which had been given over to allotments and city farms were gradually taken up for urban development. But recently, there has been a renewed interest in urban farming – albeit for very different reasons than before.