How urban farmers can now 'see the light' to improve their crop yields
Researchers have developed a new formula to allow urban farmers to design their own ‘light recipe’ - a combination of different colours of lighting that could help increase crop yields in vertical farms.
The research project, conducted at Grow It York, an indoor urban community farm based in a shipping container at SPARK in the city, developed a mathematical model that could help inform urban farmers of how light varies in different areas of a confined space as well as how to use the information to design improved lighting systems.
The team at the University of York and Vertically Urban, a horticultural lighting manufacturer, looked at how the plants in various parts of a contained farming facility might experience light.
Plants near a wall, for example, could experience brighter light because light will bounce more in that area.
They then investigated how these differences in light impacted crop growth of kale, radish and sunflower shoots.
Dr Daphne Ezer, of the university’s Department of Biology, said with more than six billion people living in urban areas by 2050, there would be a growing need to ensure those living there had access to fresh fruits and vegetables, especially as climate change threatens crop yields.
She said one potential to the issue was having indoor urban farms that house dense shelves full of crops, also known as vertical farms.
Such agricultural systems are experiencing significant growth, due to rising demand for locally sourced, sustainable food.
However, Dr Ezer said because of how many lights there are in a vertical farm, energy usage can be high, and many vertical farms do not have the experimental capacity to find the precise combination of lights that would improve their yields while reducing their carbon footprints.
The lights in vertical farms can be highly controlled, enabling farmers to precisely design farming conditions to maximise yields, but many vertical farms are small scale, fitted into compact urban spaces, and so taking ‘time-out’ to research different lighting practices to increase yield is not commercially viable.
Will Claydon, the lead researcher of the study, said: “These vertical farms might have a light recipe that is ‘good enough’, but it would be a risk to try new light treatments, because it could risk their commercial production.
"To tackle this problem we came up with a creative mathematical modelling strategy, and our key insight through this process is that even in a small vertical farm, there is a lot of variety in light colour and intensity in different parts of the farm.”
“We were able to see which aspects of light quality are most important for each species of crop, and we hope this new understanding could help pave the way for other vertical farms to optimise the light treatments in their farms, with the benefit of not having to pause production.”
The researchers believe the new “light recipe” model could mean that more vertical farms will be able to increase their yield and energy efficiency, enabling more fresh living greens to be produced in urban centres.