Vetiver grass may be best defense against worldwide erosion problems

February 03, 1993|By The Los Angeles Times

WASHINGTON -- Vetiver is a coarse, stubborn grass that grows 6 feet tall, and under warm tropical sunlight may send roots down 12 feet or more. Its strength may present it with a bright future.

The National Research Council has concluded that the little-known, if far-flung, grass could be a powerful weapon against a major environmental threat -- soil erosion from the wind-swept plains of the United States to the African sub-Sahara threatened by the expanding desert.

The study was released last week.

What makes the species useful is its habit of growing from a bunch that extends three feet or so in diameter, sending up stems so tough that a strong man can break them only with difficulty.

At the ground, a single row of plants is said to produce a barrier so dense that not even a snake will penetrate it.

The plant originated in India and was transplanted by Colonial botanists who discovered that its roots contained an oil that made a perfect base for perfumes and fragrances. It was established in the United States early in the 19th century.

The survey by the NRC, undertaken with funds from the U.S. Agency for International Development, the U.S. Department of Agriculture and the World Bank, shows that vetiver has already proven itself as an erosion-control barrier in a wide variety of settings.

In the Philippines, it is being used to help restabilize roads severely damaged by a 1990 earthquake. In China, plans are under way to cultivate it extensively in five provinces. In Nepal, it is being planted to protect irrigation canals.

And at Fort Polk, La., it is used to prevent silt from washing into streams from land torn up by tank treads.

Although the NRC concludes that much more research is needed, it says experience suggests that vetiver is "a potential breakthrough."

In the galaxy of worldwide environmental problems, soil erosion ranks high. Twenty billion tons of soil are swept away each year by wind and water. In sub-Sahara Africa, the rate has increased 20-fold in just three decades, leaving a third of the continent threatened by desertification.

In the tropics, clear-cutting forests exposes millions of new areas to the threat.

And in the United States, $18 billion is spent each year for fertilizer to replace the nutrients lost to erosion.

Vetiver appears promising because of its potential for massive, inexpensive use.

The further good news is that many strains of the plant are sterile. Hedges employing it have stayed in place for decades without spreading.

This means that it does not pose a threat of the kudzu debacle visited on the southeastern United States.

Early in this century, kudzu was brought into the United States from the Far East, with the objective of controlling erosion.

It served that purpose admirably in the raw hills of Georgia and Alabama, but it spread over buildings, climbed utility poles and blocked drainage canals. Its range now extends as far north as West Virginia.

"I was skeptical at first," said Nobel Laureate Norman E. Borlaug of Texas A&M University, who chaired the study. "But I've seen vetiver at work. And I know that in these times of great ecological concern about what is happening to our soil because of erosion, vetiver could indeed play a very useful role in many places. I see all sorts of potential."

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