Urban Farming in the Modern World
Our world today is unarguably an urban one; urban in the sense that population and wealth concentration in cities are higher than they have ever been in the course of human history. More than half of the world’s population now lives in urban areas, compared to less than 40 per cent in 1990 and only around 20 per cent in the early 1900s. And future projections show no sign of decline in this trend. By 2050, it is estimated that city dwellers will represent 80 per cent of the global populace. This major shift in geographic demographics has had numerous significant impacts on how human populations build, organise and maintain their societies.
One such impact has been on the way food is produced and distributed. The industrialisation of agriculture, which evolved in tandem with modern urbanisation, drastically increased the amount of food that farmers could produce and then send to urban centres. Even though fewer and fewer people are actually farming—in the United States, for example, only 2 per cent of the population are farmers—improved agricultural technologies and better transportation infrastructure have meant that fewer people have to; the same amount of farms can feed a much larger population and can reach markets even halfway across the world.
But as urban populations swell and more people give up life in the fields for life behind a desk, the demand is becoming harder to meet. And unfortunately, this will only worsen. The United Nations estimates that food production will need to increase by 70 per cent by 2030 to meet basic demands. It’s difficult to imagine how this demand will be met when farmland is running scarce due to urban sprawl and to the fact that we are farming land at faster rates than the earth can replenish it; soil erosion is now exceeding soil formation.
In the face of this reality, city residents and planners across the world have jumped on the urban farming bandwagon. Urban farming—which utilises urban spaces such as buildings, vacant lots and backyards to grow food or raise animals—offers many promising benefits. The most obvious one is immediate access to agricultural yields, which also means that fewer resources—natural and otherwise—are used in the transportation of food, resulting in a lower carbon footprint. Another benefit has to do with the type of agricultural system most often used in urban farming: hydroponics. With hydroponic systems, a plant’s roots are continuously bathed in a solution of water mixed with essential nutrients, negating the need for soil. Using less of Earth’s soil leaves more opportunity for natural soil formation and replenishment. Lastly, due to the edifice-centric landscape of urban environments, it’s much easier to shield plants from weather and seasonal extremes. As a result, urban agriculture yields are between 15 and 20 times greater than those of traditional methods.
Some exemplary models of urban farming exist in the world today. One such model is an underground farm in Tokyo, Japan, at Pasona Tokyo Headquarters. In a 43,000 square foot space, people are growing 200 different kinds of species, including fruits, vegetables and rice. The plants are grown using both hydroponic and soil-based farming methods, and all are grown without sunlight. In the absence of natural light, the plants are sustained by artificial lighting, such as metal halide lamps and high-pressure sodium vapour lamps. An intelligent climate control system monitors humidity, temperature and breeze.
On the other side of the globe, rooftop greenhouse farming has been the most effective solution thus far. One of the most successful has been BrightFarms in New York city. This 15,000 square foot commercial rooftop greenhouse produces and sells around 500 pounds of produce each day. The facility boasts automated sensors to activate lights, fans, shade curtains and heat blankets, and has irrigation pumps that are used to catch rainwater. The greenhouse’s location was intentionally set up near supermarkets and restaurants so that the produce reaches the clients—consisting mainly of supermarkets and restaurants—the same day that it is harvested, reducing the business’s carbon footprint while at the same time guaranteeing the freshest produce possible.
Another promising agricultural innovation that is starting to take off in the same city is the idea of vertical farming. Attributed to Columbia University professor Dickson Despommier, the idea involves building a glass skyscraper with several floors for agriculture. Because temperature, humidity, airflow, lighting and nutrients can be controlled to create the optimum conditions for plant growth, yields from one skyscraper are projected to feed up to 50,000 people each year. The only challenge is making sure that all of the plants get adequate sunlight exposure. However, engineers have designed a conveyor belt system that would rotate/move crops around the window for natural light while providing artificial light to areas farthest from the windows.
It’s important to note, though, that even with urban agriculture exploding, there are significant obstacles to be overcome. One challenge is supplying farms with adequate amounts of uncontaminated soil. Soil in and around urban areas more often than not contains high amounts of lead, which is poisonous to humans. But even using soil-less hydroponic systems requires reliable and safe water sources that are already scarce. Cities generally have difficulty providing adequate and clean water to their populations, and with global climate change threatening water supplies in many regions of the world, this is becoming all the more challenging. However, if recent agricultural technology developments are any indication, farmers, scientists and engineers are well on their way to discovering solutions to these issues.