Crops that prefer the city, i.e. cucumbers, potatoes and lettuce, can have 4 times better yields than if they were grown in the countryside.
Currently, 15-20% of global food is believed to be grown in cities, including 5-10% of all legumes, vegetables and tubers.
As city living continues to become more common around the world, the team behind the new study wanted to investigate the viability of urban agriculture as a way to improve food security, resilience and sustainability.
Hundreds of studies were analyzed to find the cultures that prefer the city
“Despite its growing popularity, there is still quite a lot we don’t know about urban agriculture, such as whether crops that prefer the city are similar to conventional agriculture, or even what crops are commonly grown,” says the environmental researcher Florian Payen, from Lancaster University in the United Kingdom.
Through an analysis of 200 previous studies, covering 53 different countries and over 2,000 data points, the team was able to get some definitive answers. Crucially, the analysis covered ‘grey’ spaces (such as roads and rooftops) as well as green spaces (such as parks).
In terms of urban spaces that work best for cultures, there was no clear winner. However, some types of crops are particularly suited to certain ways of growing, the research shows, according to the study Science Alert.
What was discovered in the analysis?
For example, water vegetables (such as tomatoes) and green leafy vegetables have high yields in hydroponic environments, where water is used instead of soil.
Foods like lettuce, kale and broccoli are better suited to be grown vertically, researchers have found. The study also showed that urban agriculture will work better for certain types of produce than others.
“Surprisingly, there was little difference between overall yields in indoor and outdoor green spaces, but there were clear differences in the suitability of crop types to different gray spaces,” says Payen.
“You can’t grow apples in a room with five or ten layers of growth, but we found a study that was able to grow wheat that way,” the researcher continued.
What is urban agriculture good for us?
What remains unclear is how profitable urban agriculture is compared to rural agriculture. The cost of operating climate controlled environments for growing food and hiring any necessary staff are factors to consider.
The development of urban agriculture could be beneficial in a number of different ways: from being better equipped to survive the next pandemic to reducing the environmental cost of food production; we now have some solid data on how viable urban-preferring cultures are.
Further research could look at how easily certain urban farming techniques could be scaled up and how city pollution might affect crop quality. There is much more to explore, but this is a solid base to start from.
“This is the first step. This is the strength of this data set, so that planners and decision makers can see whether it is worth investing in rooftop gardens or greenhouses, for example, or whether hydroponics would be better,” says Payen.
The research was published in Earth’s Future.