Las Cruces, New Mexico
December 4, 2006
The contrast is evident in the
1.5-acre checkerboard of grass plots near New Mexico State
University's golf course. One square of grass, about the size of
a kitchen table top, is abundant with thick, vigorous grass.
An adjacent plot, grown under identical conditions, is almost
barren, with a single clump of grass stubbornly clinging to
life. NMSU's Bernd Leinauer, a turfgrass specialist for the
Cooperative Extension Service, points out runners from the
lively plot of grass have encroached into the neighboring plot.
The plots are among 22 different varieties of turfgrass planted
about three years ago in a research project designed to test the
effect of low quality, salty water on the grass. Three types of
water - potable water as a control, saline water provided by
New Mexico State University's
Office of Facilities Services (OFS) and a 50-50 blend of saline
water and potable water intended to mimic effluent water - are
used to irrigate the plots.
The results vary depending on the variety of grass. The nearly
barren plot was planted with tall fescue, a cool-season grass
often used in residential landscaping. The vibrant, salt-loving
grass - seashore paspalum - was discovered growing on a Hawaiian
golf course.
"That seems to be a grass that shows promise," Leinauer said.
Why attempt to grow grass with low quality, salty water? In New
Mexico, much of the ground water supply is salty, and large
reserves of underground water around the state are generally
untapped because they would have to be treated to be usable - an
expensive process. Effluent water from municipal wastewater
treatment systems also is limited in how it can be used. But
using poor quality water for yards, parks and recreation fields
is a way to save better water for human consumption.
Leinauer's research also looks at the plants' ability to
withstand temperature fluctuations between seasons and even
between day and night. In some parts of New Mexico, like the
Gallup area, daytime highs can drop 60 degrees to nighttime
lows.
"That is extreme for any plant," Leinauer said.
So far, the research plots have tested the ability of the turf,
whether seeded or planted with sprigs, to become established in
one growing season and then survive through the first winter.
Now, Leinauer, with the help of graduate student Casey Johnson
and doctoral student Yoshi Ikemura, is looking at the long-term
viability of each species, an important consideration when
deciding what to plant in a yard or park with an expectation
that the grass will grow well for many years.
Two species are showing particular promise: seashore paspalum
and inland salt grass, a native New Mexico species that grows on
rangeland and along the banks of the Rio Grande. Inland salt
grass is exceptionally well-suited to salty conditions and is
very cold tolerant.
"It can withstand water at salinity levels close to sea water,"
Leinauer said. Two varieties of bermudagrass, NuMex Sahara and
Princess 77, both bred at New Mexico State University (NMSU),
also are doing well in the salinity tests.
NMSU's reputation as a research facility for salinity testing is
growing, and Leinauer's research recently expanded into a
five-acre test site near the NMSU football stadium, which is
being developed with support from OFS and the Water Resources
Research Institute. Part of the test site will be planted with
grass from seed companies that have contracted with NMSU to
conduct salinity research.
"We have the capability to really screen turf grasses for salt
and cold tolerance," Leinauer said. In addition, NMSU is
conducting national variety trials for Kentucky bluegrass and
tall fescue, which include 100 different varieties of each
species. NMSU was one of numerous universities that competed for
the chance to host the trials. These trials, as well, test for
salinity tolerance. |