By Lisa McLean
Guelph – It takes a lot of work – and a lot of water — to grow healthy trees and shrubs for Canada’s ornamental plant sector. The industry, which boasts approximately 3,500 nurseries across Canada, uses an estimated 190 million cubic metres of water every year.
But new research suggests this is two to three times more water than healthy trees need. And soon a new tool will be available to help nursery managers determine when to turn on –and turn off – the hose.
Jared Stoochnoff, a University of Guelph graduate student in the School of Environmental Sciences Controlled Environment Systems Research Facility, is pioneering a new irrigation management strategy designed to reduce water consumption and mitigate the environmental impact of ornamental nursery operations.
“Because many nursery irrigation managers lack reliable ways to quantitatively predict a plant’s actual water requirements, they tend to err on the side of caution and overwater,” Stoochnoff says. “This results in unnecessarily high water and fertilizer run-off that negatively impacts local watersheds.”
Stoochnoff’s team used high-tech sensor equipment to measure plant water status and quantify crop water stress tolerance thresholds. When they put those irrigation schedules based on actual requirements to the test, they reduced the nursery’s water use by 60 per cent without affecting the total growth or wholesale value of the crop.
“It’s not economically feasible to implement the equipment we were using at every nursery in Canada, but by characterizing the relationships between crop water stress levels, weather conditions and species-specific water stress tolerance thresholds, we’re now able to predict optimal irrigation frequency using onsite weather station data,” says Stoochnoff.
Stoochnoff wrote a prototype program that used onsite weather station data to predict plant water stress tolerance thresholds. Each time the threshold was reached, the program triggered irrigation and alerted Stoochnoff via text message. He was able to monitor the nursery’s current weather conditions and water use to date, and could even trigger irrigation directly from his cell phone if needed.
As a next step, Stoochnoff’s team will develop the program into an app that can be made available to a larger group of nurseries for testing. He says the program will be flexible depending on the nursery’s irrigation preferences.
“Once adopted by the nursery sector, this has the potential to conserve millions of litres of water each year and reduce the environmental footprint of ornamental nursery operations,” says Stoochnoff.
Financial support was received from the Ontario Ministry of Agriculture, Food and Rural Affairs, Canadian Nursery Landscape Association, Landscape Ontario, and The Gosling Research Institute for Plant Preservation. In-kind contributions of materials, labour and field site access were provided by Connon Nurseries, C.B. Vanderkruk Holdings, ICT International and Root Rescue Environmental.
This project was funded by Growing Forward 2, a federal-provincial-territorial initiative.
Photo source: J. Stoochnoff