Vertical farming is becoming more popular. How does a vertical farm work?
By: Dr inż. Jacek Skudlarski, SGGW
Nowadays, farmers, especially fruit and vegetable producers, are struggling with the problems caused by climate change. The factors affecting plant growth include long-term water shortages, violent and heavy rainfall, hailstorms, and frost. Hence, is it possible to grow plants without taking into account the weather conditions? It turns out that it can be possible.
Vertical farming – an alternative agriculture method
The solution is offered by vertical farms representing a new type of agricultural production known as vertical farming. This type of “farms” can operate not only in rural areas, but also in the suburbs or even in the centers of urban agglomerations, thus shortening the food supply chain.
What is Vertical Farming?
Vertical farming is the agricultural process in which crops are grown on top of each other, rather than in traditional, horizontal rows. Vertical farms are mainly located indoors, such as a warehouse, where they have the ability to control the environmental conditions for plants to succeed. Growing vertically allows for conservation in space, resulting in a higher crop yield per square foot of land used. That solution saves lots of space without reducing productivity. Vertical farms can produce one tonne of lettuce using only about 17% of the area needed for conventional farming.
The cultivation area is cut off from external conditions so they are additionally protected from possible threats.A controlled environment system creates an optimal atmosphere for plants. The risk of diseases and pests is reduced. Thanks to this, the use of pesticides is limited to the necessary minimum. Vertical farming can be considered organic.
Plants placed in the cleanrooms do not have any contact with natural obstacles, their environment is free from pests and diseases,therefore they grow quicker and their rate of vegetation is accelerated. In some cases harvesting can start just 2-3 weeks after sowing.
Vertical farming without soil.
Cultivation of plants does not require soil, using “soilless” technologies.
Hydroponics, aquaponics and vertical farming systems replace the soil. Aeroponics method of indoor farming is the one where plant roots are suspended in the air and absorb nutrients through a fog-like atmosphere. The principle of aeroponic growing is based on spraying plants’ dangling roots and lower stems with a nutrient-rich water solution in an atomized or sprayed form. This way of farming helps avoid overwatering and drying out the plants.
Hydroponics is a type of horticulture which involves growing plants without soil, by using water-based mineral nutrient solutions. Plants absorb water and minerals through the roots. Plants are grown hydroponically using an artificial growing medium and a nutrient solution designed to provide the precise amounts of nutrients needed for their development and growth.
Plants grow up to three times faster in aeroponic and hydroponic growing systems than in soil. This is because water is delivered directly to the plant’s roots.
Lack of using soil results in avoiding possible pests and diseases. The sterility of the substrate helps prevent the growth of fungi and harmful bacteria.
Aquaponics refers to any system that combines conventional aquaculture (raising aquatic animals such as snails, fish, crayfish or prawns in tanks) with hydroponics (cultivating plants in water) in a symbiotic environment. The system allows the nutrients produced by fish waste to be used by the plants, which in turn help filter the water making it suitable for the fish.
Aquaponics is more sustainable than hydroponics, where water has to be cyclically replaced. Moreover, this type of plant cultivation is free of chemical additives such as fertilizers or pesticides.
Aquaponics uses approximately 90% less water than traditional farming, and there is no need for synthetic fertilizers.
Depending on the size and specification, only one or all three systems of vertical farming can be used on different storeys of the same building.
Growing Plants under Sterile Conditions
To achieve pesticide-free crops all year round, vertical farming uses rigorous sterilization and disinfection strategies.
Sterilization can be accomplished by several means, including chemical disinfection, UV-C and ozone treatment.
Sodium hypochlorite and hydrogen peroxide is a stable and effective disinfectant when used on work surfaces of laboratories. Ultraviolet germicidal irradiation (UVGI) is a disinfection technique employing ultraviolet (UV) light to kill or inactivate microorganisms. It can inactivate microorganisms including bacteria, viruses, fungi, molds, and other pathogens.