A recent study by scientists at the Vietnam Nature and Environment Protection Association has found that Vetiver grass possesses effective water retention properties, making it suitable for use as an erosion control barrier at Ba Bể Lake, which is currently facing severe shrinkage. 
Ba Bể Lake is one of the 20 largest freshwater lakes in the world and is often referred to as the “Green Pearl” of humanity. However, the lake’s water level is gradually declining due to the increasing population in the surrounding area, coupled with sedimentation that reduces its depth. According to calculations by the Institute of Water Resources Science, approximately 700,000 tons of sediment are deposited in the lake each year. At this rate, in the next 70 years, the picturesque Ba Bể Lake may become a lifeless sandbank.
Mr. Nguyễn Công Tuỵ, a member of the Vietnam Nature and Environment Protection Association, stated that various grasses and plants have been tested over the years for their effectiveness as erosion control barriers, but so far, only Vetiver grass has withstood the test of time.
Scientifically known as Vetiver Zizanioides, Vetiver grass is referred to as Xiang-geng-chao in China and Bala in India. This grass is easy to cultivate, drought-resistant, and less susceptible to pests and diseases, with a vertical growth height of 0.5 to 1.5 meters. It thrives in both dry and wet conditions and can be planted in any type of soil, regardless of fertility. It is propagated through root clumps and stem cuttings, growing in large clumps.
Vetiver is a perennial plant that requires minimal care to quickly establish a dense barrier capable of withstanding drought and flooding. It does not produce creeping stems or rhizomes, thus preventing it from becoming a weed. The sharp leaves and fragrant roots of the plant deter rodents, snakes, and other pests.
Vetiver barriers provide excellent cushioning effects and effectively combat erosion when placed along contour lines at specific intervals on slopes. Most of the Vetiver roots grow straight down to at least 3 meters, causing minimal harm to crops while reducing surface water runoff and enhancing groundwater supplies.
In addition to serving as an effective protective barrier for the lake, Vetiver grass also helps safeguard dams, canals, roads, and hydropower lakes from sedimentation, flood control, and mitigates seasonal water loss on a large scale.
Furthermore, Vetiver leaves serve as nutritious feed for livestock. The roots are used to produce fragrances for celebrations and can also be used as bedding for livestock, as they absorb urine and retain moisture longer. In coastal areas with strong winds, Vetiver grass can serve as windbreaks to protect young fruit trees and timber species, along with pineapple plants, which act as green firebreaks and prevent soil erosion, retaining moisture in the soil. Vetiver is also used as straw for thatching roofs and covering animal shelters. The grass can be woven into baskets, and the leaves and flower stalks make excellent brooms for cleaning homes.
In 2001, the Minister of Agriculture and Rural Development signed a decision recognizing the widespread application of Vetiver grass for protecting sloped land.
Contact: Nguyễn Công Tuỵ, 48 Alley 42, Lac Trung Street (14C Group, Thanh Luong Ward), Hai Ba Trung District, Hanoi. Phone: 04 – 9872752.
Anh Thi
