Vertical farming: the pros and cons
Vertical farming is set to become a new buzzword and already there are pros and cons.
Simply put, this relatively new production technology allows for more food to be grown throughout the year in smaller spaces, without soil or natural light.
As an alternative farming technique, vertical farming offers the promise of meeting the challenges posed by increasing urbanisation, climate change, the declining availability of arable land and fresh water whilst still providing enough food for the growing global population.
Vertical farming is usually situated in large buildings, using techniques called hydroponics and aeroponics. Hydroponics is a plant growing method without soil, using a nutrient rich liquid feeding the plants. Aeroponics refers to the use of special UV lights and a misting system to grow plants, usually with their roots exposed.
Supporters of vertical farming are eager to point out the many advantages of converting concrete buildings into farms where crops can be grown year-round in a controlled environment. The most obvious one is that you don’t need a multi-hectare farm and the crops are protected from severe weather conditions minimising crops lost to hail, drought and cold snaps. Vertical farms are also more efficient as the crops mature much quicker and all produce are grown organically, with no pesticides and insecticides. Inner city farms also reduce the carbon footprint of transportation and use 95% less water than conventional farming.
Even though vertical farming presents an innovative alternative to ensure food security, there are disadvantages. First and foremost is the initial capital outlay that can vary between R7 million and R8 million depending on location, the building and overall infrastructure. Electricity usage is also higher as the plants require specialised lights. This also means that vertical farming is not entirely environmentally friendly. Whilst great success has been achieved with the vertical growing of most plants, grain variants have proven to be especially tricky to grow under hydroponic circumstances.
At this stage vertical farming is still labour intensive as the technology to propagate the plants are not yet available and workers will need specialised training in the process and technologies.
Sources: Countryfarm Lifestyles, Carte Blanche and Humanosphere
Global market research company Research and Markets predicts that the global vertical farming market is poised to grow at a compound annual growth rate of around 25.4% over the next decade to reach approximately $12.5 billion by 2025.
A rooftop garden using hydroponic technology was launched in Kotze Street in Hillbrow in October 2016. The building is owned by the City of Johannesburg and the space was offered to the Kotze Rooftop Garden Co-operative as part of a programme to counter food insecurity.
The garden is made up of two dozen rows of metal tunnels covered with shade cloth, which are raised slightly above the concrete roof.