Vetiver System

The Vetiver System (VS) is a system of soil and water conservation whose main component is the use of the vetiver plant in hedgerows. It is promoted by the Vetiver Network International (TVNI), an international non-governmental organization. The Vetiver System (VS) is a system of soil and water conservation whose main component is the use of the vetiver plant in hedgerows. It is promoted by the Vetiver Network International (TVNI), an international non-governmental organization. The Vetiver System is used in more than 100 countries for soil and water conservation, infrastructure stabilization, pollution control, waste water treatment, mitigation and rehabilitation, sediment control, prevention of storm damage and other environmental protection applications (through bioengineering and phytoremediation). The vetiver plant, Chrysopogon zizanioides, is the main component to all Vetiver System bioengineering and conservation applications. It can be used in the tropics and semi-tropics, and areas that have a Mediterranean climate where there are hot summers, and winters are temperate. When Vetiver is planted as a hedgerow across a slope, it forms a dense vegetative barrier that slows and spreads rainfall runoff. Combined with a deep and strong root system, a wide range of pH tolerance (from about pH 3 to pH 11), a high tolerance to most heavy metals, an ability to remove from soil and water large quantities of nitrates, phosphates and farm chemicals, the vetiver plant can be used for soil and water conservation, engineered construction site stabilization, pollution control (constructed wetlands), and other uses where soil and water come together. The variety of vetiver that is promoted for VS applications originates in south India, is non-fertile, non-invasive and has to be propagated by clump subdivision. Its massive, finely structured root system can grow fast - in some applications, rooting depth can reach 10–12 ft (3–4 m) in the first year. This deep root system makes the vetiver plant drought-tolerant and difficult to dislodge by strong current. It has stiff and erect stems, which can stand up to relatively deep water flow. New shoots develop from the underground crown, making vetiver resistant to fire, frosts, traffic and heavy grazing pressure. Vetiver grass is not significantly affected by pests and diseases, nor does it act as a host for pests or diseases that might attack crop or garden plants. The basic technique of soil stabilization using vetiver consists of one or more hedgerows planted on the contour. Nursery plants or slips (clumps) of about 3 tillers each, are typically planted 4-6 inches (10 – 15 cm) apart on the contour to create, when mature, a barrier of stiff grass that acts as a buffer and spreader of down slope water flow, and a filter to sediment. The development of strong plants and a deep root system requires full sun. Partial shading stunts its growth, and significant shading can eliminate it in the long term by reducing its ability to compete with more shade-tolerant species.