Vernon, Texas
August 6, 2004
Research under way at The
Texas A&M University System's
Agricultural Research and Extension Center here may one day help
Rolling Plains cattle producers fill the gaps in their grazing
season.
Wheats bred for forage and grain production are a staple crop
for many producers on the Rolling Plains. They provide forage
throughout the fall and spring grazing season, and a grain crop
come summer. But they produce little forage in late fall and
early winter, and provide no summer grazing at all.
Cattle producers typically fill the winter and summer grazing
gap with supplemental feed and hay, which can prove expensive.
"The long-term goal of our research is to develop sustainable
systems that employ several types of forages," said Dariusz
Malinowski, Texas Agricultural Experiment Station assistant
professor-forages based at Vernon. "We are looking at dual
purpose wheats and other small grains, introduced cool-season
perennial grasses, warm-season annual and perennial grasses,
annual legumes and alfalfa."
A native of Poland, Malinowski earned his doctorate in natural
sciences in Switzerland in 1995. He studied tall fescue forages
from 1996-1998 as a visiting scientist at the USDA Agricultural
Research Service Appalachian Farming Systems Research Center in
West Virginia. He conducted his post-doctoral forage research at
the Vernon center from 1998-2000 and has led the forage research
program here since 2001.
"This is a challenging climate for forage production,"
Malinowski said.
"Most rainfall occurs in May and September. In between there is
extreme heat and moderate to severe drought. At first, we tried
several species of improved introduced cool-season perennial
grasses. They can survive the winters here, but not many could
survive the extreme summer heat and prolonged drought.
"Then we looked at drought tolerant species. But they did not
produce much forage early in winter grazing season and they had
poor persistence. We had to reseed them each year."
In 2000, Malinowski decided to take a new tack.
While in Switzerland he had seen cool-season perennial grasses
native to the Mediterranean Basin that yielded well in winter
and went completely dormant in summer. Would they grow here, he
wondered?
"The severity and duration of summer drought in the
Mediterranean Basin is very similar to what we experience here
on the Rolling Plains. The cool-season perennial grasses that
evolved there just might work here," he said. "As the days grow
longer and temperatures rise, these grasses go dormant and stay
dormant regardless of soil moisture. This is called obligatory
summer dormancy.
"They break dormancy and begin to grow again when the days grow
shorter and temperatures drop, about the time that autumn rains
begin to fall."
Malinowski planted two such grasses, Grasslands Flecha tall
fescue and Maru harding grass, in 2000. They yielded well in
clipping trials and survived severe summer drought in 2001.
In 2002, other types of summer-dormant tall fescues, harding
grass and orchardgrass developed in Australia and New Zealand
were added to the trials.
All of these grasses survived drought conditions in 2002 and a
severe summer drought in 2003.
"These grasses go dormant beginning in late-May or early June,
and then break dormancy in September. They put on good growth
and managed to survive dry winter conditions," Malinowski said.
"They obtain their peak growth from January through March, and
produce nutritious forage during that time.
"After four years of severe clipping trials, their persistence
is good...they are still holding their own. They can withstand
severe defoliation, persist and regrow in this climate."
Malinowski's 2004 evaluation trials will test these grasses'
ability to withstanding different amounts of grazing pressure.
Larger grazing plots will be planted and stocker cattle provided
by Bill Pinchak, Texas Agricultural Experiment Station ruminant
nutritionist, will put these forages to the test.
"We want to see how they respond to different stocking rates,
and how the cattle will perform," Malinowski said. "We think it
may be a good idea to withhold cattle during the first grazing
season after establishment, but that remains to be seen.
"Withholding cattle that first season would give these grasses
more time to establish a larger, deeper root system. Such a root
system is a factor in the plants' ability to persist and
out-perform the summer semi-dormant grasses that have been tried
in the past."
The cool-season, obligatory summer-dormant perennials tested so
far have done well on a wide range of soil types, are less
expensive to establish and are not fertilizer-hungry.
"We typically seed them at lower rates than dual-purpose wheat,
between 18 and 20 pounds per acre or less on sandy soils. Our
seed cost ranges from $3 to $5 per pound," Malinowski said. "We
give them about 40 pounds of nitrogen per acre in early fall and
early spring, without any supplemental phosphorus or potassium.
"The best yield we have obtained in our clipping trials was
5,000 pounds per acre. The worst yield, during the driest
season, was 1,000 pounds per acre."
During the next few seasons, Malinowski hopes to develop a list
of best management practices for these forages.
"We need more information on how to manage these forages. We
also plan to add some annual legumes to the mix," Malinowski
said. "We are also evaluating alfalfa cultivars for winter
hardiness under limited irrigation, and new dual-purpose wheats
developed by Texas A&M small grains breeders.
"Limited water and recurring drought shape our forage and
grazing systems here on the Rolling Plains. We are working to
develop integrated sustainable forage systems that will give
cattle producers a better chance of success in this climate." |