October 4, 2022
About 50% of irrigation water is wasted according to the Environmental Protection Agency (EPA). And with the West being in the midst of a megadrought, this is obviously a concern.
Smart sprinklers which adapt applications to local weather conditions can be part of the solution, but spatial analysis of soil water patterns and grass health hold the key to reducing wasted irrigation water. Despite what most think, applying more water is not always the solution to poor grass health. Says Says Ruth Kerry, professor of geography at BYU, “We generally think, 'Oh, the grass is looking dead, put water on it,’ and that’s not always the solution. Our analysis helps us say, ‘This spot needs more water, but in another place, you may need to apply some fertilizer, or you may need to aerate.’ ”
Along with her colleagues and students, Dr. Kerry has been involved in research examining patterns in soil moisture and grass health on-campus fields to determine ways Utahns can more effectively use water and combat the ongoing megadrought.
Over the course of a year, Dr. Kerry and her students surveyed fields with moisture probes, electrical conductivity meters, and drones to map the water content and the health of the grass. The results were somewhat unexpected in places. “These surveys are helping us understand what factors are causing the dead grass in different places. Soils are not always wettest at the bottom of slopes and; there are places where there is too much water and grass health is poor.”
She further shared, “We are using spatial analysis to determine optimal irrigation zones and have installed sensors in these zones to tell us about the timing of the irrigation and how much water is needed for individual irrigation events.”
Dr. Kerry concludes, “If you are going to apply water efficiently, you need to know how your field varies spatially. You can determine spatial patterns quite inexpensively.” Her research has shown that simple/inexpensive measures of soil moisture can indicate spatial patterns. She suggests that homeowners with grass take simple measures like touching the ground and mapping out where it feels wet or dry; “That can give you a good indication of where to water or not.”
Dr. Ruth Kerry grew up in the United Kingdom, where she completed her studies, including a Ph.D. in precision agriculture from the University of Reading in 2004. She specializes in soil spatial analysis and land evaluation, and precision agriculture. She was previously an affiliate assistant professor at Auburn University. She and her husband are the parents of five children with her oldest just starting at BYU.