With the increasing demand for innovative solutions to traditional agricultural practices, vertical farming has the potential to offer this salvation. This technique involves the process of using hydroponics, aeroponics, and aquaponics to grow plants indoors. Vertical farming is very efficient for the cultivation of various horticultural crops particularly leafy vegetable plants such as lettuces, herbs, tomatoes, and peppers. The hydroponic systems are created using substrates often made from rock wool or similar materials and are drip-fed a controlled mixture of water and nutrients (Beacham et al., 2019). Alternatively, crops can be grown in small rafts and have a thin layer of nutrients between the plants and the water (Beacham et al., 2019). Aeroponic systems have exposed root systems that are controlled and misted with a nutrient solution and water. There is also the option of aquaponics which incorporates livestock directly into the system and similar to hydroponics, crops float atop a body of water except this water will contain fish which produces the nutrients for the crops from the organic waste produced (Beacham et al., 2019). These systems have the capability to recirculate and use 100% of the nutrients due to its closed system which helps maintain optimal conditions for crops while actively avoiding leaching which occurs in traditional practices.
These horizontal systems can then be stacked, optimizing space and production yields while also giving vertical farming its name. It is space effective as it is not limited to the horizontal land of traditional agriculture as it offers the ability to grow upward. These farms are often built or added to urban areas where there is a lack of available land or space and are often added to buildings and skyscrapers (Kalantari et al., 2018). The incorporation of these vertical farms can help limit the stress on traditional agricultural systems and contribute to food security in urban centers due to their ability to be placed anywhere. These facilities can either be compared to a greenhouse and be comprised mainly of glass (glasshouses), relying on natural light during the day while having the ability to provide controlled lighting during cloudy days, or they can be completely isolated and entirely controlled. The glasshouses require less energy input but can influence growing periods due to the lack of insulation whereas the controlled environments can be used year-round but require greater energy input (Beacham et al., 2019).
The Need for Vertical Farms
With over 90% of Americans and 70% of the world’s population anticipated to live in urban centers by 2050, it is crucial to find alternative support for our food systems to reduce the strain on current practices, maximize production, offer more locally grown produce and create healthy and accessible options for people in urban centers. A sustainable food system should consider environmental, social, and economic factors. With climate change and diminishing water supply redefining how our land can be used, it is important more than ever before to implement such innovative solutions that demand fewer land resources compared to traditional agricultural practices. Having food that is healthy, accessible, affordable, and offers little to no environmental degradation is a good framework to follow for sustainable agriculture practices which is what vertical farming offers.
Vertical farms can also provide support to the local food system and help reduce food insecurity. As previously mentioned in an article I wrote about green roofs, urban agriculture cannot be treated as the sole solution to food insecurity but it can definitely help support the system while also providing numerous social benefits. These facilities offer opportunities for education and exposure to practices that are usually isolated to areas on the outskirts of urban centers. This can simultaneously provide agriculture employment opportunities deeper into cities while also opening a conversation about food security and how to access sustainable foods.
More Advantages of Vertical Farming
Vertical farming has numerous advantages compared to traditional agriculture such as biosecurity, reduced land use, limited transportation, and therefore less fossil fuel consumption, and lack of exposure to pests, droughts, and other natural disasters (Benke & Tomkins, 2017). This lack of exposure to pests and extreme weather conditions reduces the need for excess use of pesticides and herbicides while eliminating the risk of nutrient leaching entirely. In traditional practices, up to 99% of nutrients go unused, resulting in leaching as the nutrients travel deeper into the soil, causing extreme soil acidification, and then travel even further, causing groundwater contamination. Nitrogen and Phosphorus leaching into the groundwater threatens local water quality and can pose potential human health risks while also causing eutrophication in freshwater waterways, damaging our ecosystems. With years of research into how to reduce the impact of leaching, a solution is to turn our focus to vertical farming.
In addition, not only do these facilities recycle their own water and nutrients, but they also have the capability of using local greywater and black water and have it purified in vertical farming systems and converted into potable water through evapotranspiration (Kalantari et al., 2018). These are the most water-efficient agriculture systems and can use up to 97% less water than traditional field agriculture.
Vertical farming is also capable of producing more variety of crops per capita due to the lack of restrictions on monocropping and can maintain productivity year-round with no influence of seasons (Kalantari et al., 2018).
Despite the optimal operations of vertical farming, it cannot be a cure-all for agricultural flaws for various reasons. Creating entire systems to replace agriculture plots is not economically sustainable in a short amount of time while also most likely being unable to maintain the demand for food production for entire cities and so should be implemented slowly. These preexisting plots are still fully functional and so, for the time being, vertical farming should be seen as an innovative support to this growing industry to reduce the strain on existing plots, and minimize damages caused by conventional farming, while also offering local produce to the innermost parts of urban centers.
Beacham, A. M., Vickers, L. H., & Monaghan, J. M. (2019). Vertical farming: a summary of approaches to growing skywards. The Journal of Horticultural Science and Biotechnology, 94(3), 277-283.
Benke, K., & Tomkins, B. (2017). Future food-production systems: vertical farming and controlled-environment agriculture. Sustainability: Science, Practice and Policy, 13(1), 13-26.
Jiao, Y., Hendershot, W. H., & Whalen, J. K. (2004). Agricultural practices influence dissolved nutrients leaching through intact soil cores. Soil Science Society of America Journal, 68(6), 2058-2068.
Kalantari, F., Tahir, O. M., Joni, R. A., & Fatemi, E. (2018). Opportunities and challenges in sustainability of vertical farming: A review. Journal of Landscape Ecology, 11(1), 35-60.
Lehmann, J., & Schroth, G. (2002). Nutrient leaching. In Trees, crops and soil fertility: concepts and research methods (pp. 151-166). Wallingford UK: CABI publishing.