Vertical farming is a new method of providing local food for urban centers by growing crops indoors rather than on a farm. Instead of just utilizing a rooftop for a garden, an entire building can be dedicated to growing crops. The key is to stack layers of each crop in order to maximize the use of space. Vertical farming would help to increase crop yield without requiring more land, and shifting farming from the countryside to the city would create access to local food where the demand is greatest.
Obviously, not all crops can be grown indoors. Wheat, maize and rice simply have too high of a biomass to be possible to grow indoors. For example, production of 5 to 12 tonnes of grain per hectare requires over 20 tonnes of dry wheat plant. However, crops such as tomatoes, lettuce, and other green crops are realistic options for this type of farming.
Interestingly, this type of farming does not require soil. Instead, the crops are grown hydroponically, meaning in water that contains the necessary mineral nutrient solution. The water can be reused and it is significantly easier to keep the plants clean and pest-free without the use of pesticides. When I was reading this article, my main question was: what about the sunlight? Some current vertical farms use LED lights beneath each stack of plants to light the layer below it. However, though these lights are efficient mechanisms of providing light and controlling growth of the plants, they require large amounts of energy. Before this type of farming can be considered a truly sustainable alternative the ability to provide the required light for the plants without using large amounts of energy must be increased.