By the year 2050, nearly 80% of the earth's population will reside in urban centers. Applying the most conservative estimates to current demographic trends, the human population will increase by about 3 billion people during the interim. An estimated 109hectares of new land (about 20% more land than is represented by the country of Brazil) will be needed to grow enough food to feed them, if traditional farming practices continue as they are practiced today. At present, throughout the world, over 80% of the land that is suitable for raising crops is in use (sources: FAO and NASA). Historically, some 15% of that has been laid waste by poor management practices. As mass expansion continues and globalisiation has significant impacted on natural resources and the environment, what are options for future generations and what roles can cities play in the ecosystems of the future. Well according to Dr. Dickson Despommier who is a microbiologist, ecologist and Professor of Public Health in Environmental Health Sciences at Columbia Universitywe could soon be seeing skyscrapers transformed into crop production centre’s, the idea of indoor food growing is taking off.
What is vertical farming?
The name vertical farming comes from the concept of growing more crops on a small land area, thus going upwards onto building, instead of a single crop layer pver a bread land area you have stacks of crops going vertical, its commonly associated with urban and city farming.
What are the benefits?
As consumption increases so does the production and crop yield and this method is a way to increase without using traditional land area for crops. If some of the crop growing can be transplanted away from the farmlands and into inner city areas this will have a positive impact on immediate food and supply chain within highly concentrated areas of population. It also adds food control to those living in the city.
How high can it go?
The great thing about vertical farming is that you can develop as high as you like, provided you have an efficient system that works well. The main Risks associated with vertical farming are the core things crops require, nutrients and water which must be provided, in addition you must be able to harvest the crops efficiently.
Can all crops be grown in this way?
Staples such as rice, wheat and maize which are high calorie providers are very difficult to maintain and grow on a vertical farming setup. The reason is you need an accumulated and huge biomass for these crops, on average 5-12 tonnes per hectare of grain for wheat. To achieve this you would be an accumulation of 20 tonnes upward per hectare of dry wheat plant. Therefore the weight of the plant is an issue. Ideally the most suitable crop for vertical farming would be high nutrition-high value crops such as green plants, lettuces and tomatoes.
What are the barriers to entry?
Power and energy is a key limiting factor as plants need plenty of light for photosynthesis. There have been examples in the U.S. where warehouses were converted into plant stacks. LED lighting was used for efficiency and emits less heat, which means they can be positioned closer to the plants. Plant growth can be controlled more effectively with this system however the energy consumption is still a considerable part of the process.
How can this develop?
Technology is going to be the key driver and the technology we have in new buildings, “Green builds” or refurbished old buildings, where you can have high concentrations of plants; and get enough light in order for them to grow, other things are recycling water and plant nutrients. This can also be achieved without soil and can use hydroponic systems. Less soil means cleaner production and better nutrient cycling. It’s also easier to maintain and eliminate biological pests or plant disease