Vertical farming

Vertical farming is a subcategory of ZeroAcreage Farming, also known as “ZFarming”. The latter describes forms of urban agriculture that do not require the use of conventional arable land. This includes farming in (vertical farming), at (green walls) and on top of buildings (garden and greenhouses on rooftops). Vertical farming as a subcategory, includes indoor farming and vertical greenhouses in halls, closets, cellars and basements (also known as underground farming) in buildings. Plants grow  in these places with artificial light and without soil or ground contact (inter alia due to the weight advantage) in vertically arranged shelves. The plants are mostly growing in substrates such as mineral wool, coconut fibres, hemp fibre, expanded clay etc. instead of soil. The necessary nutrients are provided in form of nutrient solutions through a water cycle (hydroponic) or over water vapour (aeroponic).

An increasing trend in modern cities is the planting of rural areas for example through the greening of inner courtyards and rooftops (-> edible cities). Moreover, vertical farming of plants over several levels is promising in order to reduce land needed for producing food and to shorten transport distances. Technological solutions are intended to adapt temperature, light spectrum and nutrients exactly to the plants’ needs and thereby allow an all-year production. Hence, vertical farming has the potential to increase food security and foster food education and the contact between producers and consumers. Ecological advantages of ZFarming are locally produced food, improved options for recycling of organic materials, drain water and waste heat. 

Disadvantages might be an additional pressure on the housing market in urban areas as well as the currently still high energy use due to the artificial lighting. Moreover, high investment costs are a barrier for new projects with vertical farming. On the consumer side the lack of acceptance of cultivation techniques based on substrate could inhibit the expansion. An organic certification of crops which has not been grown organically (meaning in soil) is so far impossible.

Vertical farming is the indoor cultivation with vertical greenhouses in halls, closets, cellars and basements of buildings. Plants grow here with artificial light and without soil or ground contact in vertically arranged shelves in which the necessary nutrients are provided through a water cycle (hydroponic) or over water vapour (aeroponic). Vertical farming will certainly become more mainstream. However, sustainability effects are mixed, particularly in terms of energy efficiency, origin of substrates, actual plastic use in terms of materials as well as the exclusivity in the technology equipment. It is unclear whether it actually contributes to food security or if the cultivation of expensive “superfoods” will be preferred in future due to the high investment costs. Adjustments in building and planning regulations could contribute to the expansion of the niche.