As populations grow, supplying sufficient amounts of nutrient-rich food will become a greater challenge. Increased vertical farming across Asia, however, will contribute to greening regional economies at the same time as addressing the sustainable food challenge.
Vertical farming practices have emerged in recent years to address the combined challenges of providing food, creating sustainable and resilient communities and effecting production in a resource-efficient manner. Vertical farming offers a means to produce nutrient-rich food close to the consumer, while using resources responsibly. Such innovative farming practices that produce what we need where we need it could positively address several of the challenges surrounding food production, storage, distribution and losses across Asia.
The world over, populations are growing, especially within cities, which is placing increasing pressure on global food systems. As populations grow, so too does the demand for food. Rapid urbanisation is putting additional strain on sourcing fresh produce to supply these growing populations. According to a policy note published by the Organisation for Economic Co-operation and Development (OECD) in 2020, the urban population in South-East Asia is forecast to grow by more than 150 million people by 2040. Across the ASEAN bloc, more than half the population, around 334 million people, live in urban areas. Combined with this rapid urbanisation in recent decades, significant dietary changes have also occurred as disposable incomes have increased in South-East Asia. Consumers have switched from rice to wheat-based products and have increased their consumption of beef, dairy products and fresh fruit and vegetables.
For many of Asia’s growing capitals and large cities, how and where the food consumed by the population is produced becomes an increasingly critical sustainability issue. When considering this rapid urbanisation against the wider context of finite land availability and the increasing scarcity of water for production, the opportunity created by closely managing resources and growing vertically becomes more compelling.
Urbanisation also presents a secondary challenge, whereby products are transported long distances to reach the consumer. Staple commodities such as rice and wheat are often grown significant distances from urban centres where populations are concentrated and produce is consumed. With greater import distances from areas of production to those of consumption, the carbon footprint of the produce increases. Importing food commodities from the wider Asia region also compounds water scarcity challenges in the catchments where produce is grown. India, for example, which supplies crops such as onions and rice to Singapore, exhibits a very high risk of water vulnerability. China and Malaysia, which combined account for the greatest proportion of imports to the country at 60% of total volume, are also at medium risk of water vulnerability.
Additionally, modern agricultural practices typically require high volumes of inorganic inputs such as fertiliser to maintain yields. Intensive monocropping practices that require increasing synthetic fertiliser applications have an associated adverse impact on greenhouse gas emissions and contribute to soil degradation and greater risks of water pollution. Relative to field production, vertical farms, when taking advantage of local conditions such as available light and temperature and proximity to consumers, present opportunities to effectively manage inputs and the associated greenhouse gas emissions. In particular, open vertical farming systems that benefit from local environmental conditions enable a reduction in their greenhouse gas emissions relative to enclosed systems, due to the reduced energy required for climate regulation and tiered lighting systems.
Vertical farms are resource-efficient due to the fact that they are fully controlled environments. Across vertical farming enterprises, it is possible to directly assess and manage the input needs of the crop. Taking precise and targeted approaches to the application of water and nutrients ensures the requirements of the crop are met, while minimising waste and over-application. Water use in these types of hydroponic systems is often 10–30% of that required for field-grown produce; this is particularly important when considering the medium to high water vulnerability risks exhibited by much of the South-East Asia region. When crops are grown within vertical farming systems, it is possible to recirculate water that is otherwise lost through evapotranspiration, which improves on these efficiencies even further. Nutrient efficiency is also improved: nutrient loss through leaching across the soil profile is a common issue in field production systems – this is minimised in vertical farms, which are optimised to deliver water-soluble nutrients directly to the growing media in which the produce is cultivated. Direct delivery and collection of tailwater also enables nutrients to be rebalanced and recirculated.
Combined with these resource-efficiency benefits, vertical farms make it possible to grow produce closer to the consumer, overcoming the import or distance from production challenge. Food items can be produced in greater proximity to the market, meeting some of the dietary needs of the population directly. Shorter supply chains also ensure that produce retains a greater proportion of its nutritional properties after harvesting.
In Singapore, the potential offered by vertical farming to green the national economy and supply food by sustainable and resilient means is being realised. Currently, Singapore is highly dependent on imports, procuring around 90% of its food needs from neighbouring countries and farther international markets. To overcome this, the government has introduced a 30 by 30 initiative to enhance food security and fulfil 30% of nutritional needs domestically by 2030. Vertical farming, which has the potential to utilise otherwise under- or unused spaces within the urban environment will be key to this goal being realised. The Sky Greens farm, for example, has developed its vertical farming system to deliver ten times more yield per unit of land area than traditional field cultivation. Spaces such as warehouses and garages will become highly productive and efficient spaces, supplying the city with leafy greens, salad vegetables and fruits.
Vertical farms, such as those bringing innovative change to Singapore’s food supply chain, will play a significant role in streamlining the process of growing high value horticulture products. As an emerging technology, the operational costs associated with heating, cooling and lighting are typically high, making these systems best suited to higher value products. Crops like green leaves, herbs and spices can be produced efficiently much closer to the market and at reasonable cost. As this technology evolves and the associated costs decrease with increased efficiency and greater innovation, the types of crops suited to these systems will diversify further. While best suited to plants with a compact habit – those that are not too tall or wide – the variety and utility of these systems to supply a greater proportion of food needs sustainably will expand.