Massive roots: Through centuries of selection for essential oil production, vetiver has a very high Root:Shoot ratio around 1:1, one of the highest among grass species. This makes vetiver an ideal plant to build up organic matter in poor or degraded soils.
In China 3.3m in 9months. Extreme depth: Vetiver roots grow vertically, slow but steady, 3.3m in first year and acquiring a total length of over 7 meters after 36 months (Seshu Lavania, ICV3 2003). This feature provides vetiver with an extremely strong anchor to the soil, which is vital in erosion control of steep slopes such as road batters and riverbanks. At the same time it makes vetiver extremely drought tolerant as it can explore deep soil moisture. The combination of the large root mass and extraordinary depth makes vetiver an excellent candidate for carbon sequestration.
In Thailand 3.7m in 12 months Penetrating: mature vetiver roots can penetrate compact soil profile such as hard pan, bitumen and mudstone
In Senegal in 6 months Fineness: The fineness of vetiver roots has two important implications: - Research showed that the tensile strength of vetiver roots increases with the reduction in root diameter, implying that stronger fine roots provide higher resistance than larger roots per unit cross section. - Providing more root surface/soil/water interfaces for microbial population and activities, which are vital in the phytoremediation of both organic and inorganic pollutants.
Reinforces the soil of this dam wall in Australia Toughness: Vetiver roots have a very high tensile strength, equivalent to 1/6 of design mild steel reinforcement, which strengthen weakly structured soil or uncompacted slopes. Vetiver roots are stronger than many tree roots.
Reinforce the soil of this batter in Fiji
New growth in clean water in Australia
Young growth in clean water in Australia
Mature growth in clean water (left) and in sewage effluent (right) in Australia
Young growth in sewage effluent ponds in South Africa (PC: Roley Noffke)
V zizanioides at the back and V nemoralis in the front (PC: PHD Phuoc)
Two V zizanioides cultivars from the DR of Congo (PC: A Ndona)
Two V zizanioides cultivars from the DR of Congo (PC: A Ndona) Kolofuma 3.3m (left) and Kikwit 2.5m (right), 1 year old
Air cells in vetiver roots (PC: Liao)
Vetiver roots sold for water flavouring in Senegal (PC: Criss Juliard)
