In agribusiness, the commercial production of leafy greens, herbs or plant seedlings using multi-level growing systems is rapidly expanding around the world. The challenge all these new businesses face is to be commercially viable against the low costs of traditional open-field farming.
Vertical Farming is a revolutionary approach to producing high quantities of nutritious and quality fresh food all year round, without relying on skilled labour, favourable weather, high soil fertility or high water use.
The Advantages Of This System
Reliable Harvest
In a well-managed Vertical Farm System, there are no ‘seasonal crops’ and there are no crop losses. Harvest times and product quality are consistent and reliable, allowing a commercial grower to confidently commit to delivery schedules and offtake agreements. Vertical Farm Systems growing areas are fully enclosed and climate controlled – removing external pressures such as disease, pest or predator attacks. It also means they do not rely on fertile arable land and can be established in any climatic region globally – irrespective of seasonal daylight hours or extremes in temperature.
Minimum Overheads
Production overheads are commercially competitive and predictable. In some locations with good selling prices and reasonable power and building rental costs a 30%+ Return on Investment can be achieved.
Optimised Energy Use
High thermal efficiency climate cells greatly reduce energy use for climate control. There is ~80% less air volume in a climate cell compared to the same size open-rack system in a warehouse.
Of course, using high-efficiency LED lighting does help reduce power usage for maximum plant growth. But in addition, lights are run in stages so that a flat total power demand over a 24 hour period is achieved. This is important as more power companies start to apply surcharges based on measured peak power demand.
Through the use of green energy and the elimination of fossil fuel tractors, irrigation pumps and other horticultural equipment the vertical system can be structured as carbon emission competitive.
Low Labour Costs
Vertical systems are fully automated growing systems with descriptive SMS text messaging for any faults. This means that only low skill levels are required to operate the system and typically the only manual labour required is for sorting and packaging harvests. On larger systems even the processing can be highly automated
Low Water Use
Plants take up water to move minerals and fuel photosynthesis. Around 95% of all water a plant takes up is returned to the atmosphere through transpiration.
The climate cells make the growing system a totally closed environment. This means that 100% of plant transpiration can be recovered and reused inside the system. Including the water used for grow medium recovery and bench washing the system uses ~95% less water than typical open-field growing and around 20% less than a normal enclosed hydroponic growing system.
Reduced Post Harvest Processing
The Systems climate cells have strong natural biosecurity features to eliminate all insects, pest and disease pressure. Human contact with growing plants is eliminated until sorting & packing. Flood and Drain watering means dry leaves throughout the growing cycle – eliminating mildew and mould pressures. No sprays, pesticides or herbicides and no animal or human contact during growing means harvests do not require holding times or expensive and produce damaging cold-chlorine washing before shipping.
Lower Transport Costs
The systems can be installed in any geographic location that offers suitable power and water supplies. Strategic positioning close to the point of sale or in distribution hubs dramatically decreases the time from harvest to consumer and also reduces costs for refrigerated storage and transport.
Optimum Crop Yields
Irrespective of external climate conditions, the System can reliably provide more crop rotations per year than open-field agriculture and other farming practices. Based on typical open-field lettuce production of 1lb/ft²/year – just 5,400ft² (500m²) of building floor area fitted with the System technology and can produce the same harvest as ~8 acres of traditional farming. Crop cycles are also faster due to the systems’ controlled temperature, humidity, and photoperiod optimisation – from seed to harvest in 28 days for most leafy greens. The optional use of Bioponic organic plant nutrients and live microbes further increases crop yields, nutritional density and flavour intensity.
Extensive Crop Suitability
The System is suited to a wide range of crops. Within each climate cell all crop growth is controlled by a full suite of adjustable parameters to maintain optimum growing conditions for each specific crop variety being grown.
Some suitable crops include: Baby Spinach, Baby Rocket (Arugula), Loose-leaf Lettuce, Endives, Tatsoi, Basil, Beet Leaf, Lambs’ Ear (Mache), Mizuna, Cos Lettuce, Butter Lettuce, Raddichio, Pak Choy
Bioponics
This vertical farm system uses Bioponics so that crops can be produced with significantly increased levels of nutrients and minerals that are essential for optimum health and performance. The term Bioponics was first coined in 2005 by the American hydroponics veteran William Texier when he patented the process.
Bioponics provides an organic alternative to normal hydroponic growing that uses synthetic fertilizers, and it’s been catching on as more and more growers enjoy the challenge of combining growing techniques in the search for healthier, tastier results.
Bioponics uses beneficial microbes, bacteria, and fungi normally only found in the very best farming land and combines these with pure sustainable organic nutrients. With Bioponics, an organic environment is created by adding beneficial microbes to the growing area, which then colonize plant roots and grow media to dramatically boost the bio-availability of organic nutrients.
The primary benefits of this type of gardening include a reduction in water usage, improvement in crop growth and elimination of chemical fertilizers and pesticides. Edible plants grown with Bioponics taste better, keep longer and have significantly higher levels of essential nutrients and minerals when compared with hydroponic cultivation and some organic produce. Hydroponics is typically based on a mixture of 17 high purity chemicals while Bioponics uses sea kelp with 73 minerals.
How Does It Work
At the simplest horticultural level, the System is a multi-level growing system using rolling benches, flood & drain watering and low voltage LED Lighting – all managed and controlled through a Modbus distributed network
Climate Cell Modules
The climate cells are where the plants are grown. Each climate cell is an insulated, closed environment with 8 levels of growing benches. Each climate cell has an integrated vertical hoist at each end for the automatic loading and unloading of rolling benches that hold the grow media and plants.
Every climate cell is automatically monitored and managed to maintain pre-set temperature, humidity, CO², watering and LED lighting levels to achieve optimum plant growth for the crop varieties planted. Any variation from presets or system function error is automatically identified, logged and reported by SMS text message or email.
Transport Modules
To automatically transfer rolling benches between the various modules of the system there is a series of motorised transport rails controlled by the system network. This automated transport system efficiently and rapidly delivers benches to the various operations such as seeding, harvesting, grow media recovery, bench wash & sterilise or onto the climate cell vertical hoists – on command and when needed.
Seeding Module
The System incorporates a mechanical gravity seeder integrated into the transport system. Supplied templates can be
easily changed for different seed counts or seeding patterns suited to a wide range of crop varieties.
As an option, the standard seeding system can be configured for either growing seedlings in cell trays or for transplanting young seedlings into the system for grow-out.
Harvest Module
The standard automated harvest configuration is optimised for the production of high-volume cut leaf crops. The harvest module uses a high-speed blade to cut the crop directly from the rolling bench and transfer it by conveyors to a designated sort & pack cold room area – typically located adjacent to the System installation, or into bulk bins for later processing.
Grow Medium Recovery Module
The Grow Medium Recovery module is an automated system that separates the clay pebbles (grow medium) from the rolling benches, sieves them to remove plant roots and stems for composting, and then rinses the pebbles clean with fresh water to preserve the colonisation of beneficial microbes used in the Bioponics system. Simultaneous with the clay pebble cleaning, the rolling benches are inverted and high-pressure washed and sterilised with a solution of hydrogen peroxide. The rolling benches are then automatically refilled with the washed clay pebbles ready for re-seeding.
A Vertical Farming System has the opportunity to produce most of the food required by city dwellers in the many vacant warehouses not currently being utilised in the cities. This will cut down on transport costs and create improved food security in the city, cutting down on the carbon emissions to transport food to the city. This might very well be one of the solutions to feeding the ever-increasing population of urban dwellers.
Courtesy of Vertical Farming Systems. For more information go to their website.