By 2050, planet Earth is projected to host around 9.5 billion people. With each individual requiring a minimum of 1,500 calories in a day, we will require another 2.1 billion acres of land, in order to continue practicing farming to meet the food demands (1), and this is not inclusive of land required for grazing domestic animals. Consideration such as clearing forests has been proposed to generate new farmland. However, the negative impact arises when clearing forests for farmland use accelerate global warming at an even more calamitous rate (1). Other than limited farming land, outdoor farming is also subjected to viruses, bacterial infections and plant pests (e.g. locusts, boll weevil) (2). These often result in significant loss in annual harvest. In addition, agriculture utilizes 70% of Earth freshwater, which is often contaminated with fertilizers, pesticides, herbicides, thus making it undrinkable (1). Clearing forest also poses the problem in resulting greater volumes of agricultural runoff, creating estuaries and barren wastelands (1).
As outdoor farming poses problems such as contaminating freshwater with soil, pesticides and herbicides, Dr. William Gericke and colleagues in 1930s perfected hydroponics, an alternative strategy to outdoor farming where plants can grow in the absence of soil (3). Also, aeroponics has been introduced to grow plants in an air or mist environment without the use of fertilizers. Despite these methods were able to solve soil erosion problems posed by outdoor farming, it does not provide a solution to the lack of farming land. With increasing civilization, especially in developed and developing countries, there is thus a need for alternative farming within these enclosed city skyscrapers to sustain the population. In 1999, Dr. Dickson Despommier and his students open the topic of vertical farming where he envisioned that a 30-floor farm of one city block could possibly provide enough food for 50,000 people (1). He suggested that hydroponics crop could be grown on the upper floor whereas chicken and fishes can be placed on the lower floor to consume plant waste.
Vertical farming was proposed to provide many potential benefits using hydroponics and aeroponics technology indoor. For example, with the world estimate to increase by 3 billion people by the year 2050 with 80% living in the urban area, vertical farming could reduce the need for additional farmland (2). Vertical farming also potentially eliminates spoilage and weather disruption, as well as avoiding weather disruption such as monsoon, tornadoes, and flooding. This increases the overall yield in the annual harvest. By reducing or eliminates the need for additional farmland, vertical farming could potentially conserve natural biomes and prevents mass extinction that is often affected in deforestation. With hydroponics and aeroponics technology, exposure to toxic pesticides and fungicides are avoided as well in vertical farming (2).
Countries such as Singapore, a land-scarce country where there is only 0.8% arable land, is suitable for vertical farming to sustain its population food demand. Every year, Singapore imports over 90% of the food the country consumes. In 2014, Singapore spent approximately S$14.8 billion importing 5.9 million tonnes of food and vegetables was the main bulk of imports. Hence, securing the supply of vegetables to feed the 5.5 million population cannot be overlooked. In order to sustain Singapore’s food supply, they venture into vertical farming. Sky Greens, the world’s first low carbon, hydraulic driven vertical farm, was commercially set-up in Singapore in 2012 (2). Over 100 nine-meter tall towers was built to provide urban sustainability where it can achieve 10 times the yield per unit area compared to traditional farms, with the use of one light bulb to power one towers and 0.5 liters of reusable water to rotate the 1.7 tonnes vertical structure, ensuring that the crops get even distribution sunlight exposure (4). Using low energy consumption and reusable water, Sky Greens was not only able to reduce carbon footprint but to sustain Singapore’s vegetable demands to a certain extent.
Other than urban agriculture, Singapore also aims to set up urban aquaculture in the Asia-Pacific Region. As traditional aquaculture have been responsible for the destruction of mangrove forests and polluting the environment, Apollo Aquaculture Group has come out with Singapore’s first home-grown vertical fish farm to solve these issues (5). The farm is 10m-high with three stories, each story has two 135 sqm pond that can each hold about 22,000 fish fry, producing 8-10 times more supply than traditional fish farming(5). Other than avoiding environmental pollution, aquaculture vertical farming in Singapore can also aim to provide a better buffer in global supply disruptions, providing sustainability to the population.
Singapore urban agriculture and aquaculture is one of the many success stories that provide urban sustainability to its own population. However, two major downside in these high-tech greenhouse industries is the price of the land in the city and labor cost. Alterrus, a company who turned a rooftop parkade into a mass-producing vegetable greenhouse, filed for bankruptcy in less than two years of operations. Due to a mechanical failure, crop productions was affected in Alterrus. In addition, the rent for the parkade was also one of the pushing factors that result in the bankruptcy of Alterrus. Another well-known local vertical farm in Chicago, FarmedHere, closed down in 2017, due to high labor, energy costs, and increasing competition in the Chicago market. Hence, despite its benefits, vertical farming is expensive to build and technology needs to be carefully planned out as mechanical problems can have a negative impact on crop yield and profits.
There are many successful vertical farming stories that help to sustain the food supply partially. Sky Greens in Singapore make use of sustainable technology to provide leafy greens to the country (4). The sustainable technology also resulted in lesser carbon footprint and using reusable water. However, many times, a lot more issues on vertical farming need to be addressed. For example, are vertically-farmed vegetables nutritious? A further problem with vertical farming is that a lot of crops (e.g. rice and wheat) could never properly develop in these artificial conditions, resulting in limited diversity of crops produced. The current vertical farming technology has placed great emphasis on crops, but not grazing domestic animals that requires a large farming land. Nevertheless, vertical farming can potentially provide many opportunities and benefits for urban sustainability.
2019-2-18-1550461327