On 30th June 2017, „BioSC in Dialogue“ offered a lecture in Aachen together with the citizen`s forum RWTHextern. Prof. Dr. Georg Noga, professor for horticulture at the University of Bonn, presented the concept of Vertical Farming, an innovative approach for food production in metropolitan areas. The lecture met an interested audience and ended with a lively discussion.
The world population is expected to increase to 9 billion in 2050. Most of the people will be living in metropolitan areas. To ensure a sufficient and healthy food supply, an additional agricultural area of 10 billion hectares would be needed which would mostly have to be provided by so far untouched ecosystems.
One concept for food supply in the world-wide rapidly growing metropolitan areas is the concept of Vertical Farming: the production of food in and on multi-level buildings. Food plants are cultivated with hydroponic techniques: they are raised in a soil-free nutrient solution and the roots are stabilized e.g. with sand or gravel, if necessary. The nutrient solutions can be recycled which allows to save up to 90% of water. Land requirements can be reduced by a multitude of 1000 compared to conventional cultivation. By increasing CO2 concentration with CO2 from the heating, yields can be increased by up to 60% and secondary metabolite concentrations by up to 35%. Moreover, the plants are protected from weather events like drought, frost or hail which allows horticulture at almost every location, and pests and diseases are easier to control.
Prof. Noga presented different pilote facilities which combine plant production with animal production, e.g. cultivation of fish, or which have a supermarket integrated. He presented calculations that the vegetables needed in a city like Bonn could be provided by a Vertical Farming facility with the size of an average car park.
However, this kind of plant cultivation ist mainly applicable to vegetables and herbs. In the course of breeders` activities to reduce the size of fruit trees it may become suitable for fruits as well. But potatoes, cereals, rice and maize will still have to be cultivated outdoors in the future.
A main disadvantage of Vertical Farming is the need for additional lightning with LED lamps. This requires a lot of energy and causes high running costs and high producer`s prices. Currently, LED manufacturers work intensely on improving energy efficiencies. Despite the problems, Vertical Farming is already being practiced, e.g. in South Korea where high population density and strong air pollution make it necessary. Prof. Noga pointed out the considerable research and innovation potential of Vertical Farming.
The about 50 guests had many questions and comments. For instance they questioned whether Vertical Farming can be cost-efficient when considering real estate prices in metropolitan areas. Other contributions referred to limited numbers of plant varieties and to the cultivation of genetically modified plants. The event ended after a lively half-hour discussion.