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THE VETIVER SYSTEM
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| The Vetiver System relies on the ability of Vetiver grass, Vetiveria zizanioides to create a near perfect barrier that when placed across a slope will reduce the velocity of rainwater runoff, trap sediments, and improve soil moisture and groundwater aquifers.
The hedgerow needs little maintenance, and when harvested its byproducts can be used for forage (136KB) thatch, mulch, handicrafts, medicines, and as an ingredient to perfume. Vetiver grass is multiplied by plant division; we recommend the use of V.zizanioides cultivars originating from south India. (81KB). This type is sterile and is not considered weedy (27KB) |
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| Vetiver roots can grow as much as 3 meters in the first year. Maximum measured root depth is over 6 meters. The root s have an average tensile strength of 75 mpa. Vetiver roots increase the shear strength of soil by as much as 30-40%. (KB14)The roots are dense, penetrating, and non stoloniferous. New roots develop from the crown of the plant; thus if cut off below the crown the plant is effectively killed. The plant is able to grow over a wide range of soil and climatic conditions: temperatures ranging from -15ºC to 55ºC; pH ranging from >3 to >11; and rainfall of >300 mm to complete submergence by flood or lake water. | |||||||||
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| Vetiver grass roots form a living and dynamic wall in the soil. Because of the denseness of the leaves and stems runoff is ponded behind the hedgerow and sediment is deposited, over time natural terraces build up behind the hedgerow. Because the natural slope is changed velocity decreases and erosion between the hedgerows is less. Soil loss (and the contanimates that are associated with soil particles) can be reduced up to 90%. Vetiver roots will penetrate hardpans thus impoving soil perosity and runoff may be reduced by as much as 70% depending on soil type and slope. | |||||||||