The Emporia Gazette

February 13, 2012

• Headlines
• Sports
• Forums
• Weather
• Classifieds

• Help
• Log in
• Home

• E-mail story
• Post a comment
• iPod friendly version

In my last column, the news about the tallgrass prairie’s No. 1 enemy, the noxious week sericea lespedeza, appeared quite grim. And it is.

But I won’t leave the issue at that because those who are committed to preserving the tallgrass prairie have not come close to giving up the fight.

A quick recap of the problem: sericea’s [suh-REE-see-uh’s] aggressive, dominating spread across the prairie threatens to wipe out the native grasses, which would in turn destroy the cattle ranching industry.

In a very short time the prairie would “forest up,” as biologists say. It only takes about 50 years for an unmanaged prairie to be taken over by trees. If cattle ranching ended in the Flint Hills, the tallgrass prairie would be completely transformed into a woodland right about the time the Emporia High School class of 2009 was settling into retirement.

Welcome to the Flint Hills Forest, they’d tell their visiting grandkids.

Thankfully, researchers at our state universities are working on methods to curb sericea’s horrendous spread. As the experts noted in my last article, they’re winning some of the battles but, so far, losing the war.

With luck, some of the current research will turn that around.

A new study, launched just three months ago at K-State, is experimenting with an additive to cattle feed. Sericea’s high tannin content disagrees with the animals’ biology and they almost always avoid eating it. A previous additive experiment involving the chemical polyethylene glycol (PEG) did not produce workable results because the dosage needed to do the job was too high for FDA guidelines.

But the new study launched in June is working with natural substances that do the same thing as PEG.

K.C. Olson, an associate professor in Kansas State University’s Animal Sciences & Industry Department, explained the biochemistry to me. The high tannin content of mature sericea plants binds with proteins inside the cattle and makes the protein of that plant—and the other digesting plants—unavailable to its system. A substance like PEG binds to the tannin so that it can’t do that kind of damage to the protein.

Unlike PEG, the natural compounds that Dr. Olson is studying are inexpensive, abundant and safe. His study will determine whether or not adding them to feed will induce the cattle to literally chomp out the sericea crisis.

“If we can make cattle not have a negative experience with that plant, and they’ll eat it throughout the grazing season, two things may happen,” Dr. Olson said from his office at K-State. “First, we may be able to take pressure off our native plants that might cause them harm, and second, put enough pressure on this undesirable plant to keep it from spreading and from producing so much seed.”

The experiment is still in the test-tube laboratory stage and will eventually progress out to the pastures, where it will become a long-term operation. “It’s the animal testing that can take such a long time,” said Olson. “We’ll be working on it for several years.”

And we’ll be crossing our fingers.

Patch burning is another experimental method that shows potential. Burning is a spring ritual on the tallgrass prairie, as it allows the growth of more new grass for cattle, puts more nutrients into the soil and curbs the growth of brush and trees. With patch burning, just a section of a rancher’s grazing land is burned, which attracts the cattle to that specific area. Concentrated, hard grazing on that patch appears to take a toll on sericea seedlings.

“There are some studies done by Oklahoma State on this patch burn technique,” said Walter Fick, associate professor of range science at K-State and the region’s top sericea expert. He knows of an experiment done with yearling steers, “not an animal we think of eating sericea a lot,” he said, yet “they did seem to utilize a high percentage of the plants to the point that they might have reduced seed production.”

William Browning is experimenting with patch burning on his ranch near Madison, and other ranches are interested in the outcomes. It’s not an easy method; fire is unpredictable and burning a relatively small piece of pasture is tricky. It is much easier to go the traditional way and burn off an entire acreage, but ranchers like Browning consider it worth the effort.

Currently, pesticides are the main line of attack against sericea. Fick has specific recommendations for spraying, which he outlines in “Sericea Lespedeza Control Time Is Now,” an article available on the K-State Research and Extention website (www.ksre.ksu.edu).

Olson is convinced that science will find a solution to the sericea threat, and his attitude strikes a welcome chord of hope. “I have been alarmed in my career before,” he said. “There have been problems like sericea lespedeza before, but I bet on technology every time. We are going to beat this thing.”