Rooftop farms in cities could help ensure future food security

Delegates at an international environment conference were introduced to the concept of urban agriculture in Edinburgh yesterday. The event – organised by Scotland’s Rural College – is devoted to sustainable intensification, the need to produce more food while minimising the impact on the environment, and urban farming is one possible way of achieving this.

In a presentation given by Dr Valentini Pappa, an SRUC researcher currently working with Zurich University of Applied Science, the possibilities and practicalities of urban farming were explored. Dr Pappa's team helped develop a £500,000 aquaponic farm on a rooftop in the city of Basel in Switzerland with the aim of studying how successful the system could be.

Aquaponic farms combine fish breeding and vegetable growing in a no soil hydroponic system. They produce little to no waste, require minimal fertilisers or pesticides and can produce crops throughout the year.

Speaking at SRUC’s Sustainable Intensification Conference, Dr Pappa said: “Aquaponics can help secure food security by increasing the food production within an already used space, and because the food is grown so locally these systems are very low in food miles. Aquaponics is a key technology for resource efficiency.”

The 260m2 research farm is capable of producing 5000kg of vegetables and 800kg of fish every year. The farm has produced all sorts of vegetables including peas, salad leaves, tomatoes and courgettes.


In Basel there is an estimated 2,000,000m2 vacant rooftop space. The researchers worked out that if just 5% of that space (100,000m2) was used for aquaponic production, 8 – 20% of the fish and vegetables consumed in Basel (home to 170,000 people) would come from these urban farms.

The Basel project was run in partnership with Urban Farmers who have designed an Urban Farmers’ Box; a 18m2 greenhouse style system which they believe will produce enough fish and vegetables to feed a family of three. The system will provide 60kg of fish and 120kg of vegetables annually.