Photos courtesy of Bernd Leinauer, NMSU.
World conditions for
growing turfgrass are continually changing with water becoming scarcer, and water quality
issues are gaining increased significance. Learning the conditions under
which grasses can perform is an essential step to developing appropriate
turfgrass varieties to eventually be released. Trials must be conducted
where the turfgrasses are exposed to heat, cold and drought.
With the increased use of recycled, or effluent, water
in various locations across the U.S., screening turfgrasses for performance
with high-salinity water is a major need. The New Mexico State University
(NMSU) turfgrass screening facility provides a
testing site with wide-ranging conditions that include extremes of hot and
cold weather, drought and high-saline irrigation water. NMSU began a
program of turfgrass screening several years ago and, more recently, has
expanded its abilities to screen turfgrass under various conditions. Dr.
Bernd Leinauer, NMSU turfgrass researcher, is leading a program with
research results reaching far beyond the borders of the Chihuahuan
|Marco Schiavon, Bernd Leinauer, Matteo Serena and Elena Sevostianova are working on a number of salinity studies at the NMSU salinity screening facility.
Screening site conditions
The Chihuahuan Desert region is almost 800 miles long
and 250 miles wide, reaching from the southwestern states deep into Mexico.
It includes the Rio Grande Valley of southern New Mexico and the San Simon
Valley of southeastern Arizona. Las Cruces, N.M., home to NMSU, lies within
the region at 4,000 feet elevation, where nighttime temperatures drop below
freezing approximately 100 days of the year, and summer temperatures often
reach 105 degrees. The low humidity and seasonal changes have made Las
Cruces one of the fastest growing cities in the U.S. The location is also
one of the best sites to screen turfgrass plants for performance under
various growing conditions.
In addition to the range of climatic conditions, New
Mexico has an extensive supply of high-saline water. Leinauer said,
“Because of our geological setting, about 80 percent of New
Mexico’s groundwater has high salinity. We have data from California,
and from Phoenix, Ariz., and our water matches well with the salinity of
the recycled water used in those locations.”
NMSU’s screening facility is located on a fully
irrigated, 3-acre site at the southeast corner of NMSU’s campus, just
south of the Aggie Memorial football field. About 2.5 acres are devoted to
salinity screening. After initiating salinity studies a few years ago, NMSU
ran out of space at its first site to conduct the requested screening.
“We were contacted by a number of companies
about screening. We wanted to do it on a larger scale, but we were limited
by the amount of land and water. We asked for more land,” Leinauer
said. After receiving a positive response, setting up the new turfgrass
screening site was a major cooperative effort, with the NMSU facilities
department donating time and money to the project.
Leinauer said, “The well we drilled at our first
site was geothermal. The water came out at 160 degrees. The water was used
to heat the swimming pool and dormitories on our campus for some time. We
drilled a new well at the new site. We have a low-lying aquifer with
high-saline water, but it is not geothermal.”
Water is pumped into an 8-inch line that carries it to
a holding tank and 2-inch PVC pipes take the water to the plots. A Toro DL
2000 drip irrigation system is then used to water the plots.
Leinauer has done extensive research on subsurface
irrigation, and a number of sites in the Southwest are using subsurface
irrigation. Leinauer’s earlier studies indicated that subsurface
irrigation is an important component in water conservation since less water
is lost to drift. Leinauer noted that some companies specify sprinkler
irrigation for screening their grasses,
providing settings comparable to the type of settings
where the turfgrasses will be grown. MP rotator sprinkler heads provide
uniform irrigation. Sprinkler and surface drip irrigation are used at the
|NTEP trial plots are planted with bermudagrass in the foreground, tall fescue in the middle, and Kentucky bluegrass in the back.
The NMSU screening facility is an NTEP testing site,
and a number of seed companies have their varieties screened at the site.
Warm-season grasses in screening studies include bermudagrass, seashore
paspalum and zoysiagrass. Cool-season grasses
include Kentucky bluegrass, ryegrass and
Barenbrug USA, Inc., Tangent, Ore., is looking for
turfgrass varieties that can perform under drought conditions and in heat
and cold, as well as with high-saline water. At the same time, turfgrasses
that can perform well with lower inputs are being sought.
Dr. Joseph Wipff, turfgrass breeder at Barenbrug USA,
noted that breeding for various characteristics is essential. Wipff said,
“At the NMSU site, we not only test our current turfgrass varieties,
developed at the breeding site in Oregon, but now also develop new
varieties by screening germplasm.”
Wipff said, “The NMSU site has a saline level
close to effluent water. It gives us an opportunity to see how the
varieties perform under high salinity, and heat and cold stress.
We’ll be ready to take them for testing to other test
Wipff noted the importance of looking at the salinity
tolerance of various grasses. “We know that Kentucky bluegrass is
very sensitive to salt,” he said. “Ryegrass is a cool-season
turfgrass that has some salt tolerance, and there are differences in
tolerance between varieties. We made selections and pushed it up a notch.
Fescue is more salt tolerant than ryegrass.” He noted that the fescue
has produced an improved turf quality and is good for the salinity levels
found in recycled water.
Some grasses, such as alkali grass, have done well in
high-salinity conditions in roadside settings. The next step is to screen
turfgrasses to see how they perform through cold winters and with frequent
mowing. The best performing varieties are then ready for trials in target
areas for the development of turfgrass that can perform under both
high-salinity and cold conditions with frequent mowing.
Expanding salinity studies
The Southwest is at the forefront for water shortages,
and a number of restrictions have been placed on water consumption
throughout the region. Recycled or low-quality groundwater is frequently
used for landscape irrigation. Low-quality groundwater is water that does
not meet standards for human consumption, such as New Mexico’s
A NMSU study is looking at advanced turfgrass
establishment issues when using high-saline irrigation water, and at
associated establishment timing and fertility issues. Leinauer said,
“Matteo Serena and Marco Schiavon, graduate
students who received their undergraduate and master’s degrees
at the University of Padova in Italy, have started new projects
investigating establishment strategies when subsurface drip irrigation is
used in combination with saline irrigation water. Matteo will look at
establishment timing and fertilization to successfully grow warm-season
grasses under saline drip irrigation, and Marco will determine minimum
water requirements to establish warm-season grasses.”
An earlier NMSU study conducted by Leinauer and Casey
Johnson, at that time a Master of Science student at NMSU, looked at the
effects of saline irrigation water on turfgrass in comparison with potable
water. That study found that while high-saline irrigation water reduced
establishment of both warm and cool-season grasses, salt-tolerant
turfgrasses such as alkali grass, seashore paspalum, bermudagrass and salt
grass could be successfully established. The study also found that salinity
tolerances were greater between cultivars within a single species than
previously reported species differences, and that no significant
differences occurred in establishment between subsurface drip and sprinkler
With the wider use of recycled water, an increased
need is expected for turfgrasses that will perform well with the
high-saline levels found in the recycled water. Seed companies are likely
to increase their work in developing new turfgrass varieties that will
offer the needed qualities, and the climatic conditions and availability of
high-saline water at the NMSU screening site will continue to offer
expanded benefits in turfgrass performance screening.
Nancy Riggs is a freelance writer and frequent
contributor to Turf. She resides in Mt. Zion, Ill.