What is Vertical Farming?
Growing crops within a building is not a new concept by any means and has been widely practiced as greenhouse farming to grow crops like spices, herbs, cucumbers, peppers, tomatoes, strawberries, and flowers on a commercial scale. The advantage of such greenhouse farming has always been that the crops can be grown all the year round, thus enhancing the commercial aspect.
Urban vertical farming is the idea of applying these same methods to grow crops to sustain cities so that all the requirements for food are grown within the cities themselves under conditions that are controlled. It is estimated that a single living being needs about 300 square feet of intensively cultivated land to provide the necessary food and nutrition of 2000 calories per day. By the same standard, about 3 million square feet can easily provide for the nutritional needs of a population of 50,000 people. This can be done in a square city block that is 30 stories high. Indoor farming as in vertical farms is more intense and requires about 20-percent of the land area required in outdoor farms because of the controlled conditions in which it is done.
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Advantages of Vertical Farming
Vertical farming allows production of crops all the year round. As the environment is totally controlled, crop failures will be nil, as the growth of crops is not related to any external weather conditions. There is no run off of water from land that, besides being a waste, can also carry off soil and nutrients during intense rainfall. Transportation of the grown crops to distant cities and market places is totally eliminated as the produce is available locally. Supermarkets and other customers can even be encouraged to take away the produce on their own, thus completely eliminating any need for transport. This can drastically reduce the carbon footprint.
Existing abandoned buildings and properties that are lying unused can be converted into vertical farms. By the practice of drip irrigation, water requirements can be controlled, and because of the protected nature of such farms, water loss due to evaporation or wind will be minimal. The loss of crops due to extreme weather conditions is totally eliminated, reducing the need for things like crop insurance which does add to farm costs. It is possible to use the inedible parts of the crops to produce energy or fertilizer as collection of such material makes it easy.
Urban employment opportunities will increase and by employing local people even transportation for them can be avoided. The use of high yield seeds which are very sensitive to ground conditions can vastly increase production and thus help to reduce costs. Above all farmland can be saved and probably diverted to other uses like growing crops for conversion to bio-fuel. Alternatively such lands can be converted to forests, thus vastly improving the region’s ecology. Even the abandonment of farming activities on such land can help the land to recover from the exploitation it has previously been subjected to. Food in vertical farms can also be grown without fertilizers and pesticides because of the lesser chances of crop diseases.
City wastewater(mainly gray water, which is water coming from households with the exception of that coming from toilets) can be treated to use in such vertical farms and this could lead to much lower costs for an urban area as such treatment can be done within the city and the water supplied to the vertical farms.
The high yields in such controlled farming conditions can greatly help food production and may even lead to better seeds. A number of crops can even be grown in the same vertical farm at the same time.
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Disadvantages of Vertical Farming
No detailed studies have been made of the energy requirements of such vertical farms. The energy and resources are used in the building itself. The control of the environment and the creation of proper conditions for growth also require light. The vertical nature of the farm adds to cost for lifts and pumps. Scientists, however, can make use of piped sunlight to reduce the costs of lighting.
Greenhouses also produce gases, and this pollution within a city may reach large proportions. Plants also require carbon which they obtain from the atmosphere and most greenhouses supplement this requirement by burning fossil fuels, which can add to pollution in a city. However researchers are also working to develop materials to absorb carbon from greenhouse gases in a city’s vehicle pollution and probably such carbon sinks can be used to supplement the carbon requirement of plants in vertical farms.
It is also necessary to work on detailed costs for setting up such farms and weigh their advantages before coming to any conclusion about the advisability for such farms.