Water absorbing polymers: lawns
The current drought has revived interest in the use of polymers as soil amendments for reducing irrigation requirements of turf. The term "polymer" covers a lot of territory. The crystalline polymers promoted for landscape uses are most commonly either starch-based (which last about a year in the soil) or polyacrylamide-based (very long-lasting).
A CSU field study on Kentucky bluegrass and tall fescue conducted in the early 90's could find no advantage to using polyacrylamide polymers as soil amendmentsThey did not allow maintenance of green turf with less frequent irrigation or lesser amounts of water, and did not delay the onset of dormancy when water was withheldFurther, dormant turf did not green up more quickly when watering was resumedThese findings held true even when very high rates were used.Municipalities, golf courses, and other users of polymers have generally reached the same conclusions regarding their effectiveness on turf areas.
Some companies that market these materials for existing landscapes inject the polymer crystals into the soil. The injection equipment often does an admirable job of aeration and cultivation, leading customers to believe that the polymers are the reason for increased lawn qualitySoil aeration increases rooting and water infiltration. This enhances water use efficiency and ultimately raises lawn quality.
It should be noted that using crystal-type polymers in hanging baskets and in some container plantings can significantly reduce the frequency and/or amount of watering needed to keep plants healthy.
For more information, see the following Colorado State Extension fact sheet(s).
For more information, see the following Planttalk Colorado™ script(s).
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Updated Friday, April 19, 2013