LED technology drives suckers, hopes for net-zero UK supply

Surrounded by rows of healthy trees grown using the latest LED technology, Scottish forestry researcher Kenny Hay has not doubted that science can boost Britain’s net zero efforts.

Trays of saplings stacked nine meters (30 feet) high inside the James Hutton Institute near Dundee in eastern Scotland are early evidence to Hay and others that LED light can be relied upon to speed up its growth.

Specimens housed in the vertical farming unit there grew six times faster than with traditional open-air planting methods, according to Forestry and Land Scotland (FLS), a government agency that manages the nation’s forests.

Its growth trials, in partnership with indoor horticulture specialists Intelligent Growth Solutions (IGS), could drive a transformation in the forestry sector and help the UK reach its net zero targets faster.

“The initial results were amazing,” FLS manager Hay told AFP during a tour of the vertical farm, as a technician controlled a mechanical lift that accessed stacks of shelves filled with trays of seedlings.

“We can grow a large number of trees in a very, very small area, which will obviously help mitigate climate change.

“Now we will look very carefully at how we could integrate this into our normal processes.”

specific ‘recipe’

The vertical farm project, which occupies just 300 square meters (360 square yards), has “tremendous potential” for tree production, according to Hay.

Trials found that some young trees grew 40-50 cm (16-20 inches) tall in 90 days. A similar growth rate would take up to 18 months in an open field.

The air inside the unit is warm and humid, adjusted to the ideal temperature and humidity level for plants.

Researchers can tailor light, humidity, water, temperature and soil so that each plant has its own specific “recipe,” Dave Scott, founder of IGS, told AFP.

Water and nutrition are computer controlled and fed to the plants through a network of plastic pipes.

Vertical farms operate at much higher humidity and lose much less water through transpiration compared to trees grown in polytunnels and greenhouses.

But Scott said advances in LED lighting technology were seen as the biggest factor behind the impressive results.

Each species of tree is assigned its own unique set of LED lights, mathematically matched across the color spectrum.

“Over the past few years, LED technology has reached a tipping point, with efficiency doubling every year,” he said.

‘stretch them’

The trial has also thrown complications to overcome.

Some saplings grew too fast, leaving their roots too weak to withstand the wind once they were planted at the FLS nursery in Elgin, in the remote Scottish Highlands.

FLS and IGS are now running a new test to slow down growth and ensure that young trees can develop stronger roots.

The ability to tailor the environment for each tree sapling has helped researchers meet such challenges, Scott said.

“You can stretch them, make them smaller, you can deliberately stress them to fit the outside world. There are a lot of things you can do,” he added.

Each trial, he added, yielded better results than the last.

FLS aims to plant around 24 million new trees a year, as the demand for young trees increases amid efforts to address climate change.

But the need to plant trees quickly has also increased the demand for high-quality seeds, another of the myriad challenges facing the sector.

© 2022 AFP