Urban gardens could cover 15% of fruit and vegetable needs

Want to eat local? Why not convert urban green spaces into vegetable gardens? This is the idea suggested by a study by the University of Sheffield (United Kingdom), which looked at the potential ofAgriculture urban. According to the researchers' calculations, converting barely 10% of a city's private gardens and other green spaces could provide 15% of the local population's needs in fresh fruits and vegetables.

Green spaces cover 45% of the surface of a city

For their study published in Nature Food, Jill Edmondson and colleagues mapped the city of Sheffield using data from theOrdnance survey (State mapping service) and Google Earth, and discovered that green spaces (parks, public and private gardens, roadsides, forests …) cover 45% of the surface, a ratio roughly equivalent to that of other British cities. " If 100% of the area of ​​allotments, allotments and appropriate public green spaces were used to grow food, it could feed around 709,000 people a year, or 122% of the population of Sheffield. “, Say the authors. But as it is obviously unthinkable that all of the gardens are reserved exclusively for agricultural production, the researchers calculated more prosaically that converting 10% of private gardens and 10% of public green spaces, while maintaining the current allotment gardens, would be enough to supply 15% of the local population with fruit and vegetables, or 87,375 people for Sheffield.

Cultivating rooftops, a potential that is still under-exploited

The study also suggestsexploit the potential of flat roofs, for example by growing fruits and vegetables in hydroponics or aquaponics (combining plants and Pisces). A system which is also very ecological, because vegetables can be grown all year round in greenhouses heated by theenergy lost buildings, recovering rainwater and with minimal lighting. Although the available areas are relatively small (0.5 m² per person), " the high yield of this type of agriculture could make a significant contribution to local horticulture ", Say the researchers. According to FAO, the vegetable gardens are up to 15 times more productive than farms in rural areas. An area of ​​one square meter can thus provide 20 kilograms of food per year.

France imports half of its fruit and vegetables

Even if France is less dependent than the United Kingdom for its fruits and vegetables (France is the third European producer behind Italy and Spain), we still import more than half of our 83 kilograms of fresh fruit and 51 kilograms of vegetables we eat per year. In addition, consumers are more and more eager to buy their products near them. Urban agriculture so has the wind in stern. The Agricool startup is growing strawberries and salads in containers piloted by artificial intelligence. Some supermarkets have converted their rooftops and part of their parking lot in mini-farms, whose vegetables are sold directly in stores.

There are, however, several limits to this little horticultural paradise. First, the idea suggested in the study (pooling a large area of ​​private gardens) seems difficult to apply at the legislative and legal level. On the other hand, only a few cash fruits and vegetables are suitable for intensive cultivation above ground in urban areas. The most imported fruits in France are banana, orange and clementine. Difficult to imagine planting a field of banana trees at the bottom of his garden. In short, unless you eat exclusively salad, tomato and herbs aromatic, urban agriculture will not solve the possible tomorrow fruit and vegetable shortage. This does not prevent you from planting green beans in the garden.