Simple bales of barley now sitting in several Carroll County ponds may be the solution to a perplexing and destructive environmental problem nationwide: pond scum.

"It sounds a little weird, but it is really appealing because it is so natural," said Bryan R. Butler, a horticulture instructor with the University of Maryland. "We can get rid of harmful algae without hurting the environment and maybe push up the price of barley for farmers."

If his theory works, the state's 10,000 fresh-water ponds could be treated naturally, and straw now tossed away or used for animal bedding could become a cash crop for farmers.

Butler placed bales of barley straw in six ponds in the county early in May and left two others untreated as a comparison. He tests the ponds weekly to determine if straw inhibits algae growth.

A month into the experiment, 85 percent of an untreated pond at Union Mills was covered with scum. The county's largest pond at the Carroll County Farm Museum had eight bales floating in it and less than a 5 percent algae cover.

"We haven't had to treat it at all this summer, and that has a considerable economic impact," said Bob Kimmel, grounds manager for the Department of Recreation and Parks. "If there were any problem, everybody would be yelling that it smells and they can't fish."

The county has spent as much as $500 a season on chemicals to keep the museum pond free of algae and anglers happy.

"Algae can form scum a quarter-inch thick," said Butler. "Fish can't swim in it. It breaks down and smells. On farms, it clogs up irrigation lines and makes it difficult to water the animals."

Butler is also seeing cleaner water and healthier fish at the other test ponds.

Butler's experiment is the first U.S. test of a theory widely accepted in England, where the same research began with a minor farm mishap.

About 10 years ago in England, a hay bale fell from a farm cart into a scum-covered pond. The busy farmer did not take the time to retrieve it. A month later, he noticed the thick green muck had dissipated. He called in a research team, which reported the results in the British Phicological Journal early this decade. But the findings went largely unnoticed outside of England.

"There are not too many people walking around with that publication under their arm," said Butler.

The phenomenon caught on in England, a nation that prides itself on stately gardens and ponds, Butler said. Straw wrapped in stockings is sold to keep ornamental garden ponds clear. The English have even tested the bales in canals.

Butler heard about the British experiment about a year ago while attending a seminar on pond management. He located the scant information on the effects of barley in ponds and decided controlling algae would be the subject of his master's thesis.

With a $3,500 state grant, he has set up a lab at Hood College in Frederick to test algae samples from around the world, culturing the different types and then introducing barley straw.

"I want to see if and how it works," he said. "I am starting from scratch and replicating the British findings in my lab."

The county ponds offered him an opportunity to practice the theory. He bought 80 bales, each weighing about 25 pounds, and followed the British formula of 100 pounds of straw to each 1 acre of water surface. Depth of the water seems to have no bearing on the outcome. He tests water about 10 feet offshore and at a depth of about 1 foot.

Frequent hard rains last month have made the bales heavier, some by as much as 100 pounds. Butler has attached plastic gallon jugs to keep them afloat. He plans to remove the straw in late September, promising it will make great compost.

A few researchers think the bales act like giant tea bags, releasing compounds that discourage algae growth, Butler said.

"The water moves through the straw, much like it would move through tea leaves in a porous bag," he said. "It disperses quickly."

Butler's weekly tests have shown less and less of the stringy green algae that creates scum. As the barley decomposes, it seems to promote the growth of one-celled plants, the first link in a healthy pond's food chain, Butler said.

In an unexpected side effect, the bales are attracting wildlife to county parks. Ducks, geese and turtles have been spotted sunning on them, and Butler has found fish hiding under them.

Carolyn "Nicky" Ratliff, executive director of the Carroll County Humane Society, placed bales on the 1-acre pond at the animal shelter in Westminster last year, after she heard about the British research.

"Our pond looks like pea soup every year by the end of May," Ratliff said. "Last year we tossed in a few bales and within a month the algae had sunk. In two months, the water was crystal clear."

She never achieved those results with constant chemical applications that left her with fears of "glow-in-the-dark fish." She abandoned the chemicals this year in favor of a procedure that is both cost saving and environmentally sound, she said. When she sees a dirty pond now, she often stops to tell the owner about barley straw.

"This is not rocket science, but something you can just do and walk away," Ratliff said. "It is better for the ecology, for the animals in and out of the water and for people dependent on clean water. This is news that should go all over the state."

BARLEY HOW-TO

If you're interested in trying barley straw to combat algae in your own backyard pond, you'll find the method fairly simple.

* For each acre of pond surface, apply 100 pounds of barley. A bale usually weighs 25 pounds and is available through area grain farmers and farm supply stores for $3-$5 a bale. For a 1-acre pond, you would need four bales. You do not have to consider water depth. (For smaller ponds, use a portion of a bale.)

* Tie bales or portions of bales securely with chicken wire or bird netting to keep straw intact. Heavy rains add weight to the straw, and you may need to tie empty plastic containers to keep bales afloat - one-gallon milk containers work well.

* Remove bales after about 90 days and replace with new ones, if necessary. The watered-down bales will make good compost.

* Store unused straw in a dry place. The leftovers make good mulch, particularly for perennial gardens.

Pub Date: 7/12/98