Dr. Dariusz Malinowski, Texas Agricultural Experiment Station forage researcher, examines a stand of summer dormant cool-season perennial grasses near Vernon. (Photo: (Texas Cooperative Extension photo by Tim W. McAlavy) They say that once you taste a mouth-watering steak from a …
So when Texas scientists began noticing a change in weather patterns on the southern plains of Texas – the prime grazing land for Texas steer in recent years – there was cause for worry. Less rain in the summer and warmer weather was gradually affecting the way perennial grass grew on the plains, and created a situation that required intervention.
It was their good fortune that there is another area of the world that shared similar weather to the Texas plains – the southern desert region of Israel. Both areas are characterized by severe water deficits and extreme heat in the summer followed by mild, rainy winters.
So, it seemed fortuitous that scientists from the Texas Agricultural Experiment Station turned to Hebrew University of Jerusalem scientists to launch a joint project that could boost grazing options for livestock producers in both nations.
“This project is specifically called the ‘Role of Obligatory Summer Dormancy in Cool-Season Perennial Grasses for Improved Semiarid Grassland Ecosystems,’” laughs Prof. Jaime Kiger, the HU scientist in charge of the Israeli side of the project. “But it’s really a lot simpler than that.”
Unpredictable autumn rains on the southern Great Plains often delay the planting of the area’s most important forage crop for cattle, wheat. This delay can result in a lack of forage for cattle to graze on in the winter and spring.
“In recent years, there’s been a strong reduction in the summer rains, and it’s becoming more like a Mediterranean climate with dry summers, and wet winters,” Kiger told ISRAEL21c.
“Due to these changes to the rainfall patterns, there’s a situation arising that after a small summer rain, the perennial grasses native of the region begin to grow. Due to grazing pressure, the grass is quickly consumed by cattle. The combined negative effects of the drought and grazing is destroying the population of local perennial grasses,” added the researcher from the university’s Institute of Plant Sciences and Genetics in Agriculture in Rehovot.
Israel is home to several populations of perennial grasses that are summer dormant, meaning they are well adapted to prolonged summer droughts and high temperatures. These grasses however, are often not a very reliable source of forage for cattle.
The joint research project is studying the various factors that affect the summer dormancy of these Mediterranean grasses in the hopes of developing grass cultivars with summer dormancy traits. The cultivars can then be used to ease reliance on wheat and other forage crops that are dependant on consistent precipitation.
“As the days grow longer and temperatures rise, these grasses go dormant and stay dormant regardless of soil moisture,” said Dr. Dariusz Malinowski, Kiger’s liaison at the Texas Experiment Station based in Vernon. “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 we receive our autumn rains. They obtain their peak growth from January through March, and produce nutritious forage. They do well in a variety of soils, are less expensive to establish than wheat and they are not fertilizer-hungry,” he told the Texas A&M Ag News.
Kiger added, “We’re trying to find varieties of cultivar of perennial grasses which are adaptable to the Mediterranean climate. This means that even if it rains in the summer, these strains of grasses won’t grow – that’s the obligatory part – they’ll only start growing again with the winter-like weather.”
“The whole idea is to look on our side for the species – the cultivars which can adapt to the changing rain patterns in Texas. On the more theoretical side, we also hope to understand the regulations guiding the summer domain – what environmental signals the species send – so that dormancy is induced and maintained during the summer even if it rains.”
The end result is that the economic sustainability of the agro ecosystems of the Great Plains and degraded natural grasslands of Israel will be improved.
“The program is funded by a 2004 grant from the Texas-Israel Exchange Program,” said Malinowski. “Our objective is to develop sustainable agro-ecosystems using introduced cool-season perennial grasses on the southern Great Plains of Texas.
“Our counterparts in Israel hope to use these grasses to improve or rebuild degraded natural grasslands.”
“I’ve worked on the subject for several years, but I wasn’t aware of the problem in Texas. They approached us about two years ago and asked if we would collaborate on the project. And we prepared a proposal,” said the 62-year-old Kiger, a native of Argentina who moved to Israel in the early 70s and received his PhD from Hebrew U. in 1975.
The Texas-Israel research program will evaluate the long-term productivity, adaptability and grazing value of these grasses in both nations. Malinowski and Dr. Bill Pinchak, Experiment Station ruminant nutritionist at Vernon, recently began a grazing study using two cultivars planted in 2004. They will measure weight gains of grazing cattle and overall forage productivity this winter. The two Texans visited Israel in May 2005 to see how grasslands are managed in Israel.
“They looked at different species and varieties – and saw how they grow in a local environment, which helps them evaluate more or less the potential use for Texas,” said Kiger. “The visit was very interesting, and the results so far have been very good. Everyone is satisfied. The project is a good combination of theoretical and applied sciences.”
“Our initial research with summer-dormant cool-season perennial grasses taught us they are adapted to our climate and have real forage value,” Malinowski added. “Some of these improved grasses are already being tested on a large scale in North Texas by seed companies and producers. Our work with Israel may open the door for the development of new cultivars/varieties that are more adaptable and productive in a wider range of climates and growing conditions.”
Giving livestock producers more grazing options could prove important if Great Plains weather continues to trend toward hotter, dryer conditions.
“If you look at long-term weather records for the Great Plains, you see a gradual rise in mean annual temperatures for the past 20 years,” Malinowski said. “At the same time, you see a decline in mean annual precipitation. This is not a favorable climate shift for forage or livestock production. With each one degree rise in temperature, forages need 15 percent more moisture to sustain production.”
To further the cooperation between the two teams, Kiger said that he’s going to pay a reciprocal visit to Texas this year. And he’s looking forward to trying some of that Texas beef.
“I’m from Argentina, the home of cattle, so it’s an issue near to my heart,” he concluded with another laugh. “It’s difficult to find somebody from Argentina who doesn’t eat red meat.”