Vertical Farms Could Grow All the Wheat We Need — But at a Cost
For years, vertical farming has captured headlines, including on this very website. A new study published in the Proceedings of the National Academy of Sciences on Monday shows the practice could revolutionise the world’s ability to grow wheat.
The global population eats a lot of wheat. It’s the most widely grown crop in the world, and it accounts for approximately 20 per cent of the calories and proteins in the average human diet. As the global population grows, we’ll need more of it to sustain humanity. With arable land a premium, the new study looks at if vertical farming — a method of growing crops in vertically stacked layers — could help.
To find out, the authors created two growth simulation models of a 10-layer vertical farm set up with optimal artificial light, temperatures, and carbon dioxide levels. They found that the simulation could yield up to a whopping 1,940 metric tons of wheat per hectare of ground per year. For context, the current average wheat yield is just 3.2 metric tons per hectare of land.
It makes sense that the authors would be looking into this now. Globally, one in nine people already face hunger, and the problem could become more acute as the population increases. The world could have to produce more than 60 per cent more wheat to account for population growth. That won’t be easy; rising temperatures and other changes in growing seasons driven by the climate crisis are lowering crop yields around the world.
The new study offers an insight into how address some of these problems. But right now, scientists are only offering simulations. Actually bringing these massive wheat crop yields to fruition would come with massive challenges.
For one, vertical farming is wildly expensive. It requires massive amounts of energy to work, especially because unlike traditional farming, it requires artificial lighting systems. The authors say their simulated systems would provide a light intensity for the crops 30 to 50 per cent greater than directly overhead sunlight. Watering systems and technology to ensure optimal temperature and air quality conditions in these indoor environments would also be costly — not to mention energy-intensive. Depending on how the systems are powered, that could be a problem for the climate. Previous research shows that powering these systems could require vastly more energy than our current high-emissions food system.
“No one has ever attempted to grow food crops under artificial lighting that’s as strong as sunlight, much less stronger, for the simple reason that it would require too much energy,” Stan Cox, a scientist and plant breeder at the Land Institute in Salina, Kansas, said in an email.