The Vetiver Grass System --- A General Description

There are twelve known varieties of vetiver grass, the most important is Vetiveria zizanioides. For centuries the oil extract from the roots of V.zizanioides has been used in the perfume trade. Indigenous peoples have recognized vetiver for its medicinal uses, for thatching, mulch, and feed, and for soil and moisture conservation. In more modern times (1950s) the sugar industry used vetiver grass quite widely as contour conservation hedges and for the stabilization of road sides and embankments. Vetiver once thought to be confined to wetlands thrives over a range of ecological conditions. It grows both on highly acidic (< pH4) and alkaline soils (pH11). Its roots will grow to depths of 3 - 4 meters . It is not effected seriously by pests or diseases. Many cultivars are non flowering, these when combined with a non spreading root system prevents "escape". Each clump of vetiver is extremely dense, so dense that if configured correctly will act as a near perfect filter. The grass is easy and cheap to establish, and needs minimum maintenance.

When planted as a contour hedge it acts as a continuous filtering system, that slows down rainfall runoff, reduces rilling and gullying, and collects soil sediments at the hedge face. Soil and nutrient loss is reduced, soil moisture and ground water improves significantly, and natural terraces and ground leveling develops behind the hedge. An important feature is that vetiver grass takes up minimal space and is virtually non competitive with adjacent crops. Apart for soil conservation uses vetiver is now an important grass for the stabilization of road and railroad embankments, river banks, canals, bridge abutments, landslide prevention, water quality improvement, waste management, etc.

In south India, near the city of Mysore farmers have grown vetiver for years as hedges to demarcate farm boundaries, just as farmers in Kano, Nigeria, have done so for centuries (V. nigratana). Since the mid 80's vetiver technology has been introduced to over 100 countries. Dissemination was achieved through videos, slides, newsletters, journal articles, and small books - all of value to end use users - farmers, extension workers and NGOs. Demand for information accelerated after a National Academy of Sciences (Washington DC) scientific review of vetiver under a committee chaired by Dr. Norman Borlaug. The published report "Vetiver Grass - The Thin Green Line Against Erosion" endorsed the use of vetiver grass and called for further efforts to introduce vetiver as a major technology for soil and moisture conservation in the tropics and sub tropics.

Research has been carried out by numerous agencies working in tropical areas. Research by CIAT in Colombia (1800 mm rainfall per annum) shows soil loss reductions from 143 tons (no protection) to 1.3 tons per hectare (protected by vetiver), no reduction in crop yields, and reduced water run off. At ICRISAT south India (650 mm per year) soil loss reduction is significant and the rate of runoff in these dry areas is greatly reduced, by as much as 60%. Yoon (Malaysia) and Materne (Louisiana) have undertaken some remarkable and practical demonstrations of its use, function, and management. In recent years work by Australian, Chinese, and Thai scientists point to the use of vetiver for the mitigation of environmental problems resulting from toxic minerals, waste disposal problems, and low water quality. At the same time feed back from users and small farmers in Africa from Ethiopia to South Africa and to Senegal, India, China, Central America, South America and the Philippines all confirm the tremendous potential of the grass and its use in soil and moisture conservation.

For a current world overview go to: paper (presented at recent International Vetiver Conference)

For more information go to: archives