Vetiver grass, also known as Chrysopogon zizanioides is a perennial grass of the Poaceae family. It is native to India and popularly known as Khus.
Morphology
Vetiver grass has a gregarious habit i.e. grows in bunches. Its shoots grow from the underground crown and make the plant frost and fire-resistant. The shoots allow the plant to survive heavy grazing pressure.
The leaves can grow up to 120-150cm long and 0.8cm wide. The plant stems are erect and stiff thus can resist deep water flow. Under clear water, the plant can survive up to two months.
It can grow up to 1.5metres tall and forms clumps as wide with tall stems, long, thin and rigid leaves. This grass has a unique feature in that its roots grow downward to a depth of 2-4 meters within the first year.
The root system of vetiver grass is finely structured and very strong. The grass has neither stolons nor rhizomes. Due to these features, the vetiver plant is highly drought tolerant and can help to protect soil against sheet and other types of erosion. Furthermore, new roots can grow out of buried nodes in case of sediment deposition.

Soil and Water Conservation uses
The roots grow downwards, 2-4meters which is deeper than some tree roots rather than forming a horizontal mat of roots, common with most grasses. This makes vetiver grass to be an excellent stabilizing hedge for stream banks, terraces and rice paddies and protecting the soil from deep sheet erosion. The roots strongly bind to the soil, therefore it cannot dislodge. Vetiver grass has been used to stabilize railway cuttings or embankments in geologically challenging situations. This has been in an attempt to prevent mudslides and rockfallls. The Konkan railway in Western India is a being example. Farmers in Kajulu East- Kisumu County,Kenya have also planted this grass to stabilize their land against erosion which has destroyed fertile lands. The plant also penetrates and loosens compacted soils.

Run-off mitigation and water conservation
Vetiver grass has close-growing clums which block the run-off of surface water. It slows water flow velocity and thus increases the amount absorbed or infiltrated by the soil. It can also withstand a flow velocity of up to 5m/s (16ft/s).
Mulch of vetiver increase water infiltration and reduces evaporation. This makes it to protect soil moisture under hot and dry conditions. Splash erosion is also controlled by the plant.
Other uses
Vetiver grass is also used for crop protection. It uses its hairy architecture to attract pests such as the stem borer (Chilo partellus). This pest lays its eggs on the grass but the hair prevents the larvae from moving on the leaves. Thus, they fall on the ground and perish. Vetiver mulch acts as a weed control mechanism in cocoa, coffee and tea plantations. It forms a thick mat barrier that allows the additional nutrients to be available when the mulch breaks down and soil organic matter builds up. The leaves of the grass are also used as an animal feed to cattle, goats, sheep and horses. It is also used to develop oils, flavors and ropes.