University of Sheffield study reveals the potential of urban agriculture to save food
Growing fruit and vegetables in just 10% of city parks and other urban green spaces could provide five servings of fruit and vegetables for 15% of the local population, according to research in England. The data relates to the city of Sheffield, which has an estimated 45% tree plantation rate, but it is an interesting indicator even for less forested cities.
In a study published in the magazine Nature of foodAnd academics from University of Sheffield Institute for Sustainable Foodin the United Kingdom, investigated the potential Urban agriculture By mapping the green and gray spaces in the city that can be used Urban farms.
They found that green spaces, including parks, gardens, allotments, roadsides and woodlands, cover 45% of Sheffield, a similar figure to other UK cities. Community gardens, common in England, cover 1.3% of this area, while 38% of green space consists of home gardens, which have immediate potential to start growing food.
The multidisciplinary team used data from Ordnance Survey It's from Google Earth To reveal that another 15% of the city's green spaces, such as parks and roadsides, also have the potential to be turned into vegetable gardens or community plots.
Combining home gardens, allotments and suitable public green spaces would open up 98 square meters per person in Sheffield to growing food. This equates to more than four times the amount of 23 square meters of space currently used for commercial gardening across the UK.
If 100% of the city's available green space was converted into Urban farmsThe production can feed approximately 709,000 people a year with the five daily servings of fruit and vegetables recommended by the World Health Organization. This number is equivalent to 122% of the population of Sheffield.
Even with a more realistic conversion of only 10% of home gardens and 10% of available green space farmsIn addition to maintaining the current land area, it will still be possible to provide fresh food for 15% of the local population – 87,375 people.
The path to food security
These forecasts represent a likely trajectory for the UK, which sells only 16% of the fruit and 53% of vegetables grown in the country. to implement Urban farms It can significantly improve food security in the country.
The study also examined the potential Urban agriculture Soil-free, they are developed on flat surfaces and in methods such as hydroponics, where plants are grown in a nutrient solution, and aquaponics, a system that combines fish and plants. These technologies could enable year-round farming with minimal lighting requirements, using greenhouses powered by renewable energy and heat captured from the buildings themselves, while collecting rainwater for irrigation.
In Sheffield city centre, flat roofs cover 32 hectares of land, the equivalent of half a square meter per resident. Despite the low number, researchers believe the high yield of soilless farming could represent a significant contribution to local horticulture.
The UK currently imports 86% of its total tomato supply. In Sheffield, if just 10% of identified flat roofs in the city center were converted to soilless tomato farms, it would be possible to increase production enough to provide one in five rations of fresh food to more than 8% of the local population. This drop increases to more than 60% if three-quarters of the flat surface area is used Urban farms.
The UK currently relies entirely on complex international supply chains for the vast majority of its fruit and half its vegetables, but research suggests there is enough space for the country to grow its own food in its own home garden.
“Even farming a small proportion of available land can transform the health of urban residents, improve a city’s environment and help build a more resilient food system,” says Dr Jill Edmondson, an ecologist at the University of Sheffield and lead author of the study.
Significant cultural and social changes will be needed to realize this enormous potential for urban agriculture. “It is important that authorities work closely with local communities to find the right balance between green space and horticulture,” says Professor Duncan Cameron, co-author of the study and director of the Sustainable Food Institute at the University of Sheffield.
“By carefully managing green spaces and using technology to create distribution networks, it may be possible to see the emergence of 'smart food cities', where local producers can support their communities with fresh, sustainable food,” the scientist speculates.
In large cities like São Paulo, where there are fewer green urban areas, but with more rooftops, it is also possible to imagine huge potential for building construction. Urban farms And improving supply networks.
