As scarcity of land in urban areas for agriculture becomes a greater concern, new technological advancements have seen a growing recognition of the value of urban farming.
Is it possible to farm in the city?
While traditional agriculture requires large quantities of arable land, urban farms reduce this need by employing methods that harness the advancement of technology.
The United Nations estimates that the world population will reach over 9 billion by 2050, out of which two-thirds will be living in urban areas. A study recently published in the journal Bioscience, estimates that overall food production needs to be increased by 25%-70% between now and 2050. However, at present, over 80% of arable land suitable for agriculture is already being used.
As of 2020, there is the equivalent of about 30 ha (74 acres) of operational vertical farmland in the world.
Vertical farming refers to large scale, mostly indoor, systems where crops are grown vertically in layers of racks. It incorporates controlled-environment agriculture, which aims to optimise plant growth, and harnesses technology to reduce the reliance on soil-based farming techniques.
The advantage of vertical farming technologies is the increased crop yield that comes with a smaller unit area of land requirement. Additionally, crops are resistant to weather disruptions because of their placement indoors, meaning less crops lost to extreme or unexpected weather occurrences. Vertical farming is also less disruptive to the native plants and animals, leading to further conservation of the local flora and fauna.
Controlled-environment agriculture (CEA) is the modification of the natural environment to increase crop yield or extend the growing season. CEA systems are built in enclosed structures such as greenhouses or buildings, where greater control can be exerted on environmental factors including humidity, air quality, temperature, lighting, water, humidity, carbon dioxide levels, and plant nutrition.
A hyper-controlled environment that can be manipulated to replicate the desired climate needed, allows for greater flexibility in the varieties of crops grown.
Most people would be familiar with hydroponic plants which are a type of horticulture and a subset of hydroculture, which is a method of growing plants, usually crops, by using a water-based mineral nutrient solution instead of soil. This system can grow plants and vegetables faster and year-round. Plants grown this way usually yield more, require less space, and conserve soil and water.
However, such a system would require quite a bit of investment. Additionally, constant monitoring is required as water-based micro-organisms can creep into the solutions. If a disease appears, all plants in the system will be affected, and without soil to serve as a buffer if the system fails, plant death will occur rapidly.
Growing a hydroponic garden demands technical expertise and production is limited compared to field conditions.
Benefits vs drawbacks
Efficiency vs Economics
While urban farming makes the most efficient use of arable land, the investment cost to set-up the farm could be quite substantial. Thus, for urban farming to be sustainable and worthwhile, the yield needs to be consistent for a long period of time.
Crop Resistance vs Crop Immunity
As crops are grown in controlled environments, typically indoors, these crops are unaffected by severe weather conditions. However, as the crops grown in the same vertical farm tend to be monocultures, the risk of disease could decimate the crop.
Environmental Conservation vs Energy Use
By not encroaching on the natural habitats of local flora and fauna, these ecosystems can continue to thrive and be biodiverse. However, vertical farms require copious amounts of energy to supply the lighting, heating,and cooling needed to create a suitable environment.
 Fatemeh Kalantari et al – Opportunities and Challenges in Sustainability of Vertical Farming: A Review (2017)
 Fatemeh Kalantari et al – A Review of Vertical Farming Technology: A Guide for Implementation of Building Integrated Agriculture in Cities (2017)
 Merle H Jensen – Controlled environment agriculture in deserts, tropics and temperate regions – A world review (2002)
 Inter-American Institute for Cooperation on Agriculture (IICA)- Farming Change: growing more food with a changing resource base (2012)
 Anwesha Chatterjee et al – Implication of Urban Agriculture and Vertical Farming for Future Sustainability (2020)