As Phoenix continues to set heat records and the future of water in Arizona remains uncertain, some researchers are looking for ways to keep trees healthy with less water. They want to make sure Arizona has more trees to provide shade from the sun, but conserve resources at the same time.
With the help of a Regents Grant from the Arizona Board of Regents, researchers at Arizona State University and University of Arizona have been testing out different smart tree watering strategies that are scalable and cost effective.
They tested out four different techniques including rainwater harvesting, organic mulch, and two different hydrogels — those absorb water up to 500 times their weight and keep the moisture along tree roots.
Bo Yang is an associate dean for research at the College of Architecture, Planning and Landscape Architecture at UA.
“We did [an] analysis. If we use this mulching practice or some of the hydrogel combinations, we may save about 1,700 gallons of water per year, per tree, if we apply this to a larger scale,” Yang said.
The experimental treatments also maintained 22-37% higher soil moisture content compared to conventional drip irrigation.
As a result of their findings, the research team was selected for an Honor Award in the research category by the American Society of Landscape Architects, the highest level of award in the field. The team will accept their award at an official ceremony taking place this month in Washington, D.C.
"We are trying to expand the scope and reach out to more of the communities, counties, governments and nonprofits to elevate the profile of this research and really promote this new technology we are developing," Yang said.
Team members at ASU will also use artificial intelligence and machine learning models to demonstrate how smart irrigation techniques can be applied at scale to further benefit water savings and heat mitigation in Arizona’s urban environment. They hope it will inform water use policy and guidelines.
ABOR has granted a no-cost extension of the grant to continue the project.