San Antonio, Texas
November 4, 2005
It's a turf battle, and the
"combatants" are various Central Texas turfgrasses. Numerous
turf types and cultivars will be denied water for 60 days to
evaluate their drought recovery potential. Only the fittest will
survive.
To establish this research,
Texas Cooperative
Extension specialists in soil and crop sciences and
agricultural engineering entered into an agreement with the San
Antonio Water System Conservation Program and the Turfgrass
Producers of Texas.
Earlier this year, researchers discussed methods that would meet
San Antonio Water System needs for developing turfgrass
recommendations.
Through their trade organization, turfgrass producers provided
sod, as well as input on the types of grasses to be evaluated.
Ultimately, 25 types or cultivars of grasses were chosen for the
two-year-plus study. One buffalo grass, eight Bermuda grasses,
seven St.
Augustine grasses and nine zoysia grasses were selected.
"We needed to set up a field research site where we could test
the drought tolerance and recovery of grasses in the San Antonio
area," said Dr. David Chalmers, Extension turfgrass specialist
and one of the principal investigators for the study. "It was
also important that these results could be put to practical use
by our research partners."
During August and September, team members constructed a research
site south of San Antonio and sodded plots with 25 grasses.
Grasses were planted on 4 inches of native soil over an
impermeable plastic barrier.
Washed sod was used to reduce differences in rooting from the
soil on the sod.
Later this year, a 5,000-square-foot shelter will be built on
the site.
The shelter will act as a barrier to rain in order to maintain a
consistent 60-day drought period. After that period, the grasses
will be irrigated for 60 days to allow for recovery. Each grass
will be evaluated during the drought period and the recovery
period.
"Drought studies are scheduled to begin in July 2006 on the
grasses we've already planted," said Roger Havlak, the Extension
turfgrass specialist in charge of data collection and plot
maintenance. "The same set of grasses will be planted in a
second set of separate plots in September 2006 to repeat the
60-day drought cycle, beginning in July 2007."
Grasses will have been established for more than nine months
before the 2006 drought treatment, he said. And data from the
2006 study will be used to produce a list of drought-tolerant
grasses.
"This data will be helpful because the City of San Antonio has
passed a conservation ordinance that addresses new turf
installation that is supposed to go into effect January 2007,"
Havlak said. "The ordinance will require new home construction
to have at least 4 inches of topsoil before a lawn is
established, and that's the amount we used in our plot testing.
It will also require that during new home construction,
landscapers plant grasses most likely to survive a 60-day
drought. Of course, it's imperative that this is all based on
good science."
Similar drought conservation measures may be adopted in other
municipalities where water conservation is a priority, Chalmers
said.
"This study and similar studies that may come after it will be a
good thing for turf in Texas," he said. "We will have practical,
science-based data that will allow for better turfgrass
selection and to help promote the conservation of water, which
is a vital resource for our state." |