Throughout the history of mankind we have had to evolve the way we feed ourselves, from hunter-gatherers, through subsistence farming through to the industrial scale farming of today. If we are to survive the next 50 years the next evolution will have to be another “green revolution”.
To put the growth into perspective: if the world population grows as predicted to over 9 billion by 2050, over 100 million hectares of arable land will be needed – that is 20% bigger than Brazil. However, both land and water resources, the basis of our food production, are finite and already under heavy stress. Future agricultural production will need to be more productive and more sustainable at the same time. As extreme weather events become more frequent there is a higher probability of poor crop yields or failure. Meeting future demand will require increased productivity and investment in alternative practices such as urban and vertical farming.
Vertical farming – food grown in high-rise buildings in an urban environment year round – could provide many advantages; being close to the point of consumption it reduces both distribution costs and spoilage. Traditional farming of mono-crops are vulnerable to pests and disease, this in turn means intensive use of pesticides and herbicides causing problems with agricultural runoff. Vertical farms reduce water usage through recycling, protect crops from weather and pests and reduce or eliminate the use of pesticides and herbicides. They could provide a major new role for the agrochemical industry designing and producing safe, chemically-defined nutrients for a wide range of commercial crops.
The productivity of closed hydroponic or aeroponic systems can be further enhanced by combining it with aquaculture. This combined process is often referred to as aquaponics. The inclusion of a fish farm acts as waste disposal, a source of plant nutrients as well as production of animal protein. In addition to edible biomass, bio-waste can be converted to useful products such as liquid fertilizer or bio-fuel.
Agriculture accounts for around 70% of water used in the world today so reducing the demand here helps reduce the pressure on drinking water. Typically a recirculating aquaculture system (RAS) requires the addition of 1-1.5 per cent of the total system’s volume due to lost from waste removal, evaporation and evapotranspiration from plants. The University of the Virgin Islands Agricultural Experiment Station is a commercial size aquaponic RAS. It produces 37,800 heads of lettuce and 11,000 pounds (5,000 kg) of fish per year using less than half the water traditional farming would use to produce the lettuce alone.
While the 37 floor vertical farm referenced in Up, Up and Away! The Economics of Vertical Farming by Chirantan Banerjee and Lucie Adenaeuer may be an academic study, there are already small scale production farms all over the world. Kyoto, Japan’s Nuvege is growing a variety of lettuces in a 30,000 square foot (2,800 m2) hydroponic facility with 57,000 square feet (5,300 m2) of vertical growing space. PlantLab in Den Bosch, Holland, is constructing a three-story underground vertical farm that completely eliminates the wave lengths of sunlight that inhibit plant growth. “The Plant” in Chicago is a net-zero aquaponic and hydroponic vertical farm converted from a dilapidated 93,500 square foot (8,700 m2) former meatpacking facility. Big Box Farms in New York City is a hybrid vertical farm, growing salad greens inside a one-story industrial warehouse; the hydroponics uses only 5 per cent of the water used by conventional agriculture.
Vertical farming has been the subject of many studies as to its technical and economic viability. When compared to conventional farming where agricultural technology and production processes are well understood, vertical farming is a much more unknown quantity.
However, with finite land resources a tipping point will be reached where vertical farming becomes more than just an academic exercise.
The industry needs to invest today in developing the technologies and processes that will support vertical farming as a technically and economically viable industry in the future. Studies and pilot schemes have shown that vertical farming offers a radical alternative to conventional agriculture. It is an industry in its infancy but one that has already shown tantalising flashes of what is possible. It is ready to realise further efficiencies by utilising established technologies such as robotics, advanced sensor networks and microfluidics.
Revolutions grow from necessity and drive innovation to new levels. Meeting the challenges and delivering successful solutions will create new leaders. Leaders who will help shape the future of this global industry. We’re ready to step up to that challenge – are you?