"Vertical farming is often seen as the future of food production. After all, in a closed environment, the climate is better controlled, and water can be reused. That is correct if vertical farming is compared with, for example, an open field. But what about a high-tech greenhouse: are the benefits of vertical farming still just as great?" says David Katzin and Cecilia Stanghellini, Researchers from Wageningen University and Research.
To disclose the comparison between these two cultivation methods, both researchers wrote an article for the scientific journal Journal of Cleaner Production in which vertical farming is compared with high-tech greenhouse horticulture on several variables. The researchers compared available data and knowledge about both forms of horticulture.
So what are the differences?
The Greenhouse Horticulture and Flower Bulbs Business Unit of Wageningen University & Research (WUR) discovered that the disadvantages of vertical farming often outweigh the advantages. David says, "When assessing the opportunities of vertical farming, do not look with rose-colored glasses, but with realistic glasses."
Vertical farming is the cultivation of a crop in a closed environment, for example in a container. The cultivation does not come into direct contact with the outside air and sunlight. That has many advantages. This makes it possible to control the cultivation in a very targeted manner (due to the absence of outside influences). Cultivation in a vertical farm has several advantages for reducing damage to the environment: less crop protection is needed, and water and fertilizers can be reused.
As a result, there is a lot of enthusiasm - especially in science - about vertical farming. Yet, the researchers claim that vertical farming is not necessarily the sustainable future of food production. For example, a lot of energy is needed to grow crops due to the use of artificial light, and it is very capital-intensive. According to WUR researchers, it is therefore good to compare vertical farming with other forms of food production, and in particular with high-tech greenhouses. Even in modern greenhouses, water and fertilizers are reused, and less or no chemical crop protection is used. And don't forget greenhouse benefits from (free) sunlight.
In the study, the following topics will be elaborated on: Quantify productivity and electricity requirements of vertical farm cultivation, vertical farm energy used vs. greenhouses, the transport impact of open field vs. vertical farming, the water savings and reduction of chemical use, and finally, a benchmark for evaluating vertical farming vs. greenhouses.
Results
They showed that the disadvantages of vertical farming - especially the high energy consumption - often outweigh the advantages. Even the benefit that vertical farming offers, namely making it possible to grow food anywhere in the world, is often not a benefit to the ecological footprint. For instance, lettuce grown in a vertical farm in the Netherlands can have a larger footprint than if lettuce is grown in a greenhouse in southern Italy and transported to the Netherlands by truck.
Figure 2: The total energy consumption (kWh kg-1) for the production of one kg of lettuce
"Since it is a new technology, there is still very little data on vertical farming in practice. However, the researchers have been able to outline the boundaries of vertical farming based on known scientific principles. They showed that, when considering all possible alternatives, it is rarely desirable to lose the free light of the sun," the researchers concluded.
Click here to access the research.
For more information:
Wageningen University & Research
www.wur.nl