Hold the salt, please
Even with 20 to 25 percent less water than normal, desert turfgrass can do well as long as salts in the soil are managed properly.
That’s the finding of Paul W. Brown, biometeorologist and extension specialist at the University of Arizona’s department of soil, water and environmental science. He and his co-workers found that leaching salts from the soil is key.
Thus the conundrum: does it take less water to keep turfgrass from getting thirsty than it does to leach out the salts?
“That’s the key point,” Brown says. “You can do this in the short-term and save water.” So in a dry summer, superintendents can get away with withholding water in periods of low play.
“But it does take a certain amount of water annually or at least every three years to take the accumulating salts and leach them out,” Brown warns. “In an extended period of drought, at some point leaching has to happen.”
Brown developed and oversees AZMET — the Arizona Meteorological Network. AZMET is a near-real-time agricultural weather information system with 28 stations that provide reference evapotranspiration figures for superintendents and other turf managers. He’ll be talking about AZMET and other aspects of salinity management at the Desert Turf School. Superintendents can get some quality one-on-one time with him and other extension specialists at the School, slated to run from lunch Monday, January 9 until lunch on Friday, January 13 in Phoenix at the Maricopa extension office. Credits earned will count toward GCSAA and other certifications.
Winter rains help the leaching process. So does heavier irrigation, primarily to assure germination, during fall overseeding.
Courses with saline water have a whole different set of challenges. However, in many areas, the “lose the salt” irrigation strategy is a great water-saver. “The amount you have to apply depends on what you’re demanding of the grass,” Brown explains. A city park requires one quality of grass. A high-end golf course takes a bit better quality. A football stadium needs an even better quality.”