Tree seedlings can be grown six times faster in vertical farms compared to traditional outdoor sowing methods, a new trial led by Forestry & Land Scotland (FLS) alongside agritech firm Intelligent Growth Solutions has found.
The trial is the first of its kind in the UK, and so far, the project has found that seedlings housed in a vertical farm can grow between 40-50cm tall in just 90 days. By comparison, researchers say this would take up to 18 months in an outdoor setting.
While vertical farms are typically associated with growing herbs, leafy greens and vegetables, the trial scheme highlights the huge benefits they could provide to the forestry sector.
FLS currently plants around 24 million trees each year. The use of vertical farms is a “serious consideration” for the service as it seeks to meet tree planting targets.
Five similar growing trials have already been completed by FLS at the IGS Crop Research Centre, housed at the James Hutton Institute in Invergowrie.
Species that have been successfully grown at the facility include conifers such as Norway and Sitka spruce, Douglas fir, Lodge pole and Scots pine.
Other broadleaf varieties such as Oak, Alder, Aspen, Rowan, Hazel and Birch have also been grown at the site.
According to FLS, each trial has yielded better results than the last – with tweaks being made each time to the environment including watering regimes, light settings and nutrition.
The benefits of vertical farms
Using vertical farming techniques, tree seed germination rates are significantly more efficient compared to traditional outdoor ‘broadcast sowing’. And FLS estimates the process will use around half the number of seeds currently required.
The vertical farming system is also expected to produce a more consistent and reslient product due to the customisable conditions available within the site.
Vertical farm-grown seedlings have already been planted outdoors at FLS’s Newton Nursery near Elgin, and have successfully acclimatised to outside conditions.
IGS CEO David Farquhar said the partnership with FLS has enabled the firm to “expand the portfolio or crops” that can be grown inside vertical farm environments and explore the potential applications of the company’s technology.
He said: “We are delighted to see initial results indicating the seedlings are performing well outside the precision-controlled environment in which they started their lives.
“We believe vertical farming has a real role to play in supporting reforestation projects all over the world, and this is a very exciting step towards making that a reality.”
In addition to supporting reforestation projects worldwide, it is believed that vertical farming could help reduce water wastage and cut carbon emissions for operators in the forestry sector.
Far less water is required to grow tree seedlings in vertical farms as they operate with higher humidity and lose less water compared to trees grown in polytunnels or glasshouses.
IGS said its vertical farms also recycle the water they use and can be operated using rainwater harvesting.
Kenny Hay, Tree Nursery & Seed Resource Manager at FLS, believes vertical farms could play a key role in tackling the “unprecedented threats” faced by forests globally.
He explained: “A vertical farming system for growing trees could allow us to grow many more trees – faster, more efficiently and with far less water – for planting out in the future forests of the UK.
“We are very pleased that we now have a ‘proof of concept’ and we’re excited by the potential of the system. There are very clearly significant potential benefits from using such as system, so we will now look very carefully at how we might be able to integrate this into our normal processes.”
A sixth trial is now underway, FLS revealed. The latest project will aim to slow down the growth rate of tree seedlings to get thicker root collars, making them more suitable for planting outside.