Could the Future of Farming be Vertical?

Photo: BrightAgrotech, Pixabay

Vertical farming promises a more sustainable future for growing fruit and vegetables. Instead of planting a single layer of crops over a large land area, stacks of crops grow without soil or sunlight.

The nascent technology enables farmers to grow more food on less land. Among the benefits, it reduces the environmental impact of transportation by moving production from the countryside to the cities, where most people live.

Dilapidated warehouses and factories around the globe are being transformed into urban farms to grow salads and other leafy greens at a rate that surpasses traditional farming techniques. LEDs provide the lighting plants need to grow, while sensors measure temperature and humidity levels. Robots harvest and package produce.

At one vertical farm in Japan, lettuce can be harvested within 40 days of seed being sown. And within two towers measuring 900 m2 each (actual cultivation area of 10 800 m2 and 14 400 m2), the factory can produce 21 000 heads of lettuce each day.

Indoor farming is not a new concept, as greenhouses have long demonstrated. It has existed since Roman times and can be found in various parts of the world.

Greenhouses are described in a historic Korean text on husbandry dating from the 15th century and were popular in Europe during the 17th century. In modern times they have enabled the Netherlands to become the world’s second largest food exporter.

Vertical farming offers a new take on indoor farming. Popularized by the academic Dickson Despommier, its proponents believe that vertical farming can feed millions of people while reducing some of the negative aspects associated with current agricultural practices: carbon-emitting transportation, deforestation and an over-reliance on chemical fertilizers.

Vertical farming is defined as the production of food in vertically stacked layers within a building, such as a skyscraper or warehouse in a city, without using any natural light or soil. Produce is grown in a controlled environment where elements including light, humidity, and temperature are carefully monitored.

The result provides urban dwellers with year-round access to fresh vegetables since they can be grown regardless of weather conditions, without the need for pesticides and have only a short distance to cover, from farm to plate.

Initially conceived by Despommier with his graduate students as a solution to the challenge of feeding the residents of New York City, vertical farming has since taken off around the world, most notably in the United States and Japan. According to the research company Statista, the vertical farming market is expected to be worth USD 6,4 billion by 2023.

High-tech farming

According to the UN Food and Agriculture Organization, food production worldwide will need to increase by 70% by 2050 to feed a projected global population of 9,1 billion. Vertical farming seeks to address the dual challenges of feeding a growing population that, increasingly, will live in urban centres.

By repurposing warehouses and skyscrapers, these ‘high-tech’ greenhouses reuse existing infrastructure to maximize plant density and production. One vertical farm in the United States claims that it can achieve yields up to 350 times greater than from open fields but using just one percent of the water traditional techniques require.

In general, two methods for vertical farming are used: aeroponics and hydroponics.

Both are water-based with plants either sprayed with water and nutrients (aeroponics) or grown in a nutrient-rich basin of water (hydroponics). Both exhibit a reliance on advanced technology to ensure that growing conditions are ideal for maximizing production.

So as to produce a harvest every month, vertical farms need to control the elements that affect plant growth. These include temperature, requisite nutrients, humidity, oxygen levels, airflow and water.

The intensity and frequency of the LED lights can be adjusted according to the needs of the plant. A network of sensors and cameras collects data with detailed information about the plants at specific points in their lifecycle as well as the environment in which they grow.

This data is not only monitored but also analyzed to enable decisions to be taken that will improve plant health, growth and yield. Data sets sent to scientists in charge of the growing environment enable decisions to be made in real-time, whether they are onsite or at a remote location.

Automation can take care of tasks such as raising seedlings, replanting and harvesting. It can also be used to provide real-time adjustments to plant care. One factory plans to automate its analytical process with machine learning algorithms so that real-time quality control can take into account a diverse range of data sets.

While each of these farms will implement varying levels of technology, it can be expected that as these technologies become more widespread, their adoption will increase. The use of artificial intelligence and cloud computing is not yet extensive but is likely to become increasingly important to ensure production yields remain high.

Growing pains

Despite the enthusiasm for vertical farming, its business model is not yet proven. The initial investment needed to launch a vertical farm and the electricity required to power the 24-hour lights, sensors and other technologies can be costly.

Depending on the source of the electricity used to run the equipment, it may not necessarily prove environmentally cleaner than traditional farming techniques. For this reason, a shift towards renewable energy sources could support the claim that these farms have a positive environmental impact.

At this stage, vertical farms are used primarily for growing crops that attract high market prices, such as herbs, medicinal plants and baby greens. They have not been used to grow the wheat, beans, corn or rice which feed much of the world. Its scale is not yet sufficient to meet food demands.

Vertical farming is still in its infancy. No large scale studies have yet been completed to allow a full comparison with traditional farming techniques. Despite this, it has generated much enthusiasm and, more recently, significant financial support, which may enable vertical farming to create a niche market for the supply of fresh produce to city dwellers.