With empty supermarkets highlighting the need for the UK to produce more of what it eats, a study from the Institute for Sustainable Food at the University of Sheffield investigated the potential for urban horticulture by mapping green spaces and grey spaces across Sheffield.
Most cities have approximately 45 per cent of green space (including parks, gardens, allotments, roadside verges and woodland). The study found that by converting 10 per cent of domestic gardens and 10 per cent of available green space, as well as maintaining current allotment land, could provide 15 per cent of the local population fed with fruit and vegetables.
The study also investigated the potential for year-round soil-free farming on flat roofs. Using hydroponics and aquaponics combined with greenhouses powered by renewable energy and heat captured from buildings, with rainwater harvesting for irrigation could allow year-round cultivation. If 10 per cent of the flat roofs identified within the centre of Sheffield became soil-free tomato farms, it would be possible to grow enough tomatoes to feed more than eight per cent of the population as one of their 'five a day'. This increases to more than 60 per cent of people if three-quarters of the flat roof area is utilised.
There will not be a “silver bullet” to solve food security. Food security will likely be solved through a mixture of measures from biotech, precision farming, vertical farming, etc. It may be that urban farming could be part of the solution.
Link to related article: www.sciencedaily.com/releases/2020/03/200317130713.htm