Vertical farms grow crops (particularly microgreens, leafy greens and tomatoes) in vertically stacked layers in a controlled indoor environment without soil. They yield more crops per square metre than traditional farming or greenhouses, plus they can be used all year round, grow plants faster and use less water. They range in scale from the small and rudimentary, like simple wall-mounted systems, to the large and industrial, taking over huge, cavernous warehouses.
There are three main growing methods.
Probably the simplest and cheapest method, this involves plants sat in a soil substitute (like coconut fibre, polyurethane sponges or peat moss) with the roots suspended above a nutrient-rich liquid that’s pumped up through a tank.
Using less water than hydroponics, in this method the plant’s roots are suspended in air and misted at regular intervals with a nutrient-rich spray.
Here, fish enter the fray in a closed-loop system, as their nitrate-rich waste is fed to the plant roots to act as a natural fertiliser.
Some context: the world population is growing and our global agricultural systems are unsustainable and inefficient in their use of land. Enter vertical farming. Though the vast energy needed doesn’t equal a smaller carbon footprint, the growing demand for locally grown food has led to a huge industry that’s predicted to grow faster than lettuce in fish poop – Allied Market Research estimates an increase in market size from $2.23 billion in 2018 to $12.77 billion by 2026.
The advancement of tech and software means costs are coming down and crop efficiency is increasing, while lots of information sits online. Throw in shifting attitudes around origin, and it’s clear it can be profitable – either as a primary or additional revenue stream, something plenty of restaurants, grocery stores and hotels are already doing.
Jonny Reader is lead design engineer at London-based company V-Farm, which produces vertical farming hardware and software for growers of all sizes. Clients’ needs range from buying rack systems (from around £10k) to renting out glass restaurant systems all the way to grand £500k projects. We spoke to him about the basics needed for hydroponic farms.
Any vertical farmer worth their soil replacement needs to consider these.
What’s the model?
Are you starting your own brand and selling directly to consumers (in person or online); a brandless supplier to restaurants; or supplying a market? This requires a rigorous assessment of your local demand to work out what people want or need – and who your customers will be.
How are you going to fund it?
Best practice is to prepare for one to two years of loss making. Vertical farms require up-front investment for set-up – the conditions you establish often take tweaking before you grow enough to be profitable.
Is the location right?
Your physical location needs to fit your space needs and high energy needs. The geographic location is also vital – it’s essential to reduce costs after production; packaging and transport need to be minimal expenses, hence why many vertical farms are in urban centres.
What will you grow?
It’s generally easier to grow small to medium crops like microgreens (spinach, lettuce, kale and herbs), broccoli, cabbage, cauliflower, tomatoes and chillies. Many follow a 80% greens, 20% herbs breakdown.
What outside expertise will you require?
Think about gaps in your knowledge, from the layout of your space to controlling the environment and the needs of your various crops. Jonny says, ‘Vertical farming programmes go bust because they spend a huge amount on the tech up front without getting the crop side of it right.’
How much labour will you need?
It’ll be your biggest cost (between 50% and 80%). With automation only suitable for large operations, think about how many hands you’ll need during the stages of growing, harvesting and distributing. If you work solo, harvesting demands may mean days off are a thing of the past.
This article was first published in Courier issue 41, June/July 2021. To purchase the issue or become a subscriber, head to our webshop.