Vertical Farms and Vertical Farming

The practice of growing agriculture crops in vertically-stacked layers, commonly known as vertical farming, often incorporates controlled environment agriculture (CEA) and soilless farming techniques; such as hydroponics, aquaponics, and aeroponics.

Hydroponics

Hydroponics refers to the technique of growing plants without soil. Inert mediums, such as gravel, sand, and rockwool, are used as soil substitutes to provide support for the roots. Because hydroponics have proven to increase yield per area and reduce water usage, it is the predominant growing system used in vertical farming. A study published in the International Journal of Environmental Research and Public Health found that, compared to conventional farming, hydroponic farming could increase the yield per area of lettuce by around 11 times while requiring 13 times less water.

Aquaponics

The term aquaponics is a portmanteau formed by combining aquaculture – which refers to fish farming, and hydroponics – the technique of growing plants without soil. By integrating the production of terrestrial plants with the production of aquatic organisms, aquaponics takes hydroponics one step further. In a closed-loop system that mimics nature itself, plants consume carbon dioxide produced by the fish and the water in the fish tanks generates heat that helps the farm maintain temperature at night to save energy. Given that most commercial vertical farming systems focus on producing fast-growing vegetable crops, aquaponics is currently not as widely used as conventional hydroponic systems.

Aeroponics

Unlike conventional hydroponics and aquaponics, aeroponics does not require any liquid or solid medium to grow plants. Instead, a liquid solution with nutrients is misted in air chambers where the plants are suspended. When compared to the most efficient conventional hydroponic systems, this process uses up to 90% less water. The absence of a growing medium allows aeroponic systems to adopt a vertical design. This uses gravity to automatically drain away excess liquid, which further saves energy.