CDM Assistance

Vetiver

The Vetiver System is low cost and efficient system for soil and water conservation, infrastructure stabilization, pollution control, waste water treatment, mitigation and prevention of storm damage and many other applications. Vetiver Grass, Vetiveria zizanioides, (recently reclassified as Crysopogon zizanioides) is the main component to all Vetiver System based bioengineering and conservation applications. The plant is unique. It can be used in the tropics and semi tropics, and areas such as Italy and California that have a Mediterranean type climate where there are hot summers, and winters are temperate. The roots of the grass have an average tensile strength of Mpa 75 and improve the shear strength of soil by between 30 and 40%.

How vetiver caught the world's attention in the late eighties, is a very interesting story. In 1987, noting that soil erosion is the most serious agricultural problem in the world, Richard Grimshaw and John Greenfield, two agricultural scientists of the World Bank decided this had to be tackled on war footing. During their visits to different states of India, they chanced upon the solution they were so eagerly looking for in a sleepy village near Gundlupet in Karnataka. The village evokes vivid memories in Grimshaw's mind. "We learnt from these farmers that they have been successfully growing vetiver against soil erosion for centuries. It reduced rainfall runoff by as much as 70%, recharged groundwater (villages that use vetiver have much higher water levels in their wells), and improved ephemeral stream flow."

Subsequent studies prompted the World Bank to launch The Vetiver Network (TVN), which has been disseminating vetiver technology to the world with a missionary zeal. Now there are more than 20 vetiver networks in the world and newer ones are being formed every year. In China alone, vetiver is so popular that the country now has a Chinese Vetiver Network and 6 corporations for the implementation of vetiver systems for environmental protection.

Best candidate for 'earth repair'
What makes vetiver so popular?

Water purification

One recently discovered attribute of vetiver is its capacity to purify water, and thus to help in wastewater treatment. Vetiveria zizanioides, a species widely present in India, can absorb many heavy metals, nitrogen and phosphorous from water. In studies conducted in China using vetiver to treat effluents from piggery farms, the results were quite encouraging. Using vetiver to purify water bodies is easy, too. Being hydrophyte, the plants don't require a separate medium to grow in water. The only arrangement required to make vetiver plants survive in water properly is a float to maintain the balance between roots and shoot and to make the plant stand erect. Cut pieces of bamboo make a good float.

Another widely adoptable use of vetiver is for embankment stabilisation. What is required is just timely planting of vetiver slips in linear rows across slopes. Using this technology alone, countries like China, Brazil, Philippines, Malaysia, Vietnam and the West Indies have saved millions of dollars. In recent years, China has extensively used vetiver for major highway and railroad embankment stabilisation.

Apart from its value for soil and water conservation, vetiver can check weed invasion too. "Vetiver grass grows so densely that it can block the spread of other grasses including some of the world's worst creeping grasses. In Zimbabwe tobacco farmers reportedly plant vetiver around their fields to prevent invasion of other tough grasses. In Mauritius sugar cane growers rely on vetiver to prevent Bermuda grass from penetrating their fields from adjacent road-sides. In High Range, for example, a vetiver plot established at Kundaly in the early 1990s kept Kikyu grass (Pennisetum clandestinum) from creeping in. Obviously establishing vetiver hedges along the periphery of tea fields could prevent invasion of deep rooted tough grass weeds. "

"Water ponds and tanks that are being cleaned and desilted would benefit from surrounding vetiver hedgerows to prevent future siltation, and floating platforms of vetiver on the ponds would significantly increase water quality. Spring heads can also be very effectively protected by vetiver. Additionally vetiver could be used in villages to help clean up household effluent, and stabilise those communities that live on steep slopes. "

Vetiver and vetiver oil have many medicinal uses and are claimed to cure some stomach infections and skin diseases. For those who have problems with termites it is a useful plant to grow around one's house as it is a termite deterent. A piece of the root in a bottle of water is said to purify water.

Aromatherapy (Umesh Lavania): Vetiver oil owes several beauty benefits and emotional effects. It balances the activity of the sebaceous oil glands, has deodorizing properties, and helps normalize oily skin and clear acne. It replenishes moisture in dry and dehydrated skin and has a rejuvenation effect on mature skin, as well as cuts / wounds / irritated and inflamed skin. When used regularly during pregnancy, vetiver oil reportedly prevents stretch marks. The oil strengthens the central nervous system, and is helpful in overcoming depression, insomnia, anxiety, stress, tension and nervousness (Wilson, 1995). When locally applied in rheumatism, lumbago, headache, sprain, it is a relieving embrocation. Infusion of roots is a refreshing drink in fever, inflammation and irritability of the stomach. Some people use vetiver oil as aphrodisiac (Wilson, 1995)

Benefits from using vetiver grass hedges are less easy to determine. In most instances soil loss is quickly and permanently reduced, reductions of erosion losses from 143 tons to 1.3 tons per ha. In one year are not uncommon. Short-term yield gains have been demonstrated in India resulting in estimated Benefit Cost ratios of more than 2:1. Some farmers in India have reported no crop loss in drought years when using vetiver, whilst their neighbors have lost their unprotected crops. Other benefits that should be quantified include the value of vetiver as a mulch (in China US 2 cents per kg), as a fuel (vetiver has an energy value of about 55% of that of coal), and as a fodder. Indirect benefits include value of otherwise lost soil and soil nutrients, value of increased ground water recharge, its value in upper catchment flood protection and reduced maintenance cost of embankments. If one assumes the benefits between engineered systems and vetiver grass to be the same (which they are not - vetiver’s being superior) then the low cost of vetiver compared to engineered systems (about one fifth) should rank VGT as a priority technology.

The distance between two contour lines may range from 50 to 100 m depending on the slope of the land. Soon after the first rains, vetiver slips of 10-15 cm split from the clump are to be planted along the contour line and pressed. Dipping the root of the slips in Azospirillum slurry, a non-symbiotic, free-living N-fixing bacterium, ensures better establishment and growth, as evidenced by the number of tillers and height measured at periodic intervals. Zigzag planting at 15-20 cm spacing is advantageous.

Dusting 10-percent BHC along the contour line will ward against possible termite attacks. A single tiller develops into 30 to 40 tillers per clump during the first year itself and 55 to 70 during the second year. Gap filling may be necessary during the second year. The rooting is dense, extending to 30 cm vertically and 50 cm horizontally during the first year and 50 and 70 cm, respectively, during the second year. The roots or the clumps do not hamper beyond 1 m horizontally. This is advantageous because of non-interference with the crop cultivation between hedges. The contour hedges act as the guideline for contour farming, ploughing, seeding and other cultivation operations. Each furrow acts as a miniature reservoir in conserving moisture and soil. The soil moisture was monitored. The moisture percentage was higher in the hedged areas than in the non-hedged areas. During the summer months it was 45% in vetiver hedged areas and only 20% in non-hedged areas. The soil loss in non-hedged areas was 2.5 kg/m2/yr as against 0.2 kg/m2/yr.

The Vetiver System was first developed for soil and water conservation purposes but in the last six years its role has been extended into environmental protection field, particularly in the field of wastewater treatment and solid waste landfills. Research in Australia and China has shown that VS is a very effective method of treating polluted water, domestic effluent, industrial wastewater and landfill leachate.

Purification of Polluted Water
There are two ways of improving the quality of polluted water. One is to control the input of pollutants, particularly N and P, and organic pollutants to the water body, and another is to remove these substances from water.

In China research showed that vetiver can be used to remove high soluble N and P concentrations in polluted river water (Zheng et al. 1997).

The removal percentage of total P was 76-91% after 2-week growth, and more than 98% after 3 or 4 weeks. The removal rate was higher in river 1 water than in river II water. This might be because vetiver planted in river I water had more roots and thus stronger absorbability. The removal percentage of total N was a little less than that of total P.

It was 34-45% after 1 or 2 weeks, and only 71-74% after 4 or 5 weeks. These indicate that the removal efficiency of P by vetiver is higher than that of N. Phosphorous is usually considered to be a key element in water eutrophication.

Effluent Disposal

With the potential of removing very high quantities of N and P and very rapid growth, vetiver planting can be used both to reduce the volume and to remove nutrients in effluent from sewage, abattoirs, feedlots, piggeries and other intensive livestock industries. In Australia VS was used very successfully as an integral part of a wastewater purification program in removing nutrient from effluent from septic tanks.

Best candidate for 'earth repair'
What makes vetiver so popular?