Agriculture
Vetiver on farms: soil, water, fertility, mulch, pests and forage
On farms, vetiver’s main job is managing water. A dense hedge on the contour slows runoff, spreads it, and lets it soak in, and the soil that the water was carrying stays behind the hedge. Farmers report soil loss cut by up to 90% and runoff by up to 70%, more moisture for crops, springs that flow longer and, over the years, natural terraces.
The same hedges give mulch, forage and pest control, and they cost very little to establish and keep. They suit smallholders and large estates alike.
- Soil and water conservation
- Water and drought
- Soil fertility
- Regenerative agriculture
- Mulch
- Pest control
- Forage
- Large farms and estates
- Gardens and landscaping
- Further reading
“Over five or six years it is very easy to see how vetiver has changed the slopes by holding soil and reducing runoff. My land was full of stones, but now it has regenerated its topsoil. I also cut the vetiver and use it as mulch for my crops.”
— Charles Mlambo, Tala, Machakos County, Kenya. More user stories
Soil and water conservation
Soil erosion takes the most fertile soil first. It lowers yields, silts up rivers and dams, and reduces the rain that recharges groundwater. Vetiver hedges are a very low-cost answer. Three traits make them work: deep, vertical roots that bind the soil; stiff stems that stay upright in flowing water; and close planting that forms a tight living filter.
At the hedge, runoff slows almost to a stop and drops its sediment on the upslope side. Year by year the sediment builds a terrace riser, the slope between hedges becomes flatter, and the hedge keeps growing up with it. In Ecuador, Piet Sabbe planted hedges 6–7 m apart between citrus and pineapple; within a few years, he reports, runoff had stopped and soil organic matter had risen to about 3%.
Photo essay (PDF)Design guidance: A5 DS-ON-FARM-SWCDesign guidance: D12 DS-VERTISOL-AGRICULTURE
Water and drought
Erosion control and water conservation are the same job. Rain now tends to come in fewer, heavier storms with longer dry spells between them. On an open field, runoff gathers in rills and leaves the crop unevenly watered. A vetiver hedge collects that flow, spreads it sideways along its length and lets it seep through evenly, so more of the rain soaks in where it fell.
Farmers report that crops stay green ten days or more longer in a drought, often the difference between a harvest and none. Groundwater recharge follows. At Ano farm in Ethiopia, 200 km of contour hedges were planted, and springs below them now flow all year.
Soil fertility
When farmers see that vetiver improves their soil, with higher yields and lower fertilizer bills, they take it up for erosion control too. Vetiver builds fertility in four ways: it keeps more moisture in the soil, so soil life can thrive; its roots open pores for air and water; its cut leaves become organic matter; and, working with mycorrhizal fungi, it brings up nutrients from depth that crops nearby can share.
Caleb Omolo used vetiver to stop erosion on his father’s land in western Kenya, then planted it between his coffee and mulched with the cuttings. “The termites ate all the vetiver mulch, turning it into very good soil,” he says. The bare land is now a productive food forest.
Design guidance: D5 GUIDE_AMFDesign guidance: D14 GUIDE_SOIL CARBON
Regenerative agriculture
Regenerative agriculture, which aims to rebuild soil, restore the water cycle and cut purchased inputs, only works on land that is stable. Across the Global South vetiver provides that foundation, which is why TVNI calls it a keystone plant. Its benefits arrive in layers. First the hedges stabilize land and water. Then soil organic matter, moisture and nutrients build up. Crops grow better and survive drought. Mulch cuts weeding and herbicide use, and stem borer damage falls. Across the wider landscape more rain soaks in, groundwater is recharged and streams flow longer.
Vetiver is cheap to establish, long-lived and needs little care. It has limits: it is not a food crop, it needs a correct layout and protection from grazing while young, and its benefits build up over several years. TVNI’s Vetiver Farm Model Package (D13) sets out model farm layouts with start guides and fact sheets.
Mulch
Vetiver leaves make an excellent, long-lasting mulch, and every conservation hedge produces it. Coffee estates in Ethiopia have mulched with vetiver for 50 years. Laid green, the mulch resists termites; as it breaks down it adds organic matter. It keeps the soil cool and moist, suppresses weeds, reduces the water needed for irrigation, and protects the soil from rain.
Under ordinary farm conditions vetiver produces about 20–30 tons of dry matter per hectare a year. Yields near 100 tons come only where it is irrigated with nutrient-rich water. Most growers use “chop and drop”: they cut the hedge and lay the leaves beside it. A gardener in Belize replaced his raised beds with rows of vetiver about 2.8 m apart and mulched between them; drainage and soil moisture improved, with little digging.
Pest control
Vetiver is a “dead-end” trap plant for cereal stem borers. Some stem borer moths prefer to lay their eggs on vetiver, but the young larvae that hatch there die. Research by Johnnie Van den Berg in South Africa (maize) and Lü Zhongxian in China (rice) showed the effect and led farmers to adopt it. Many farmers who grow maize or sorghum near vetiver benefit without knowing it. For rice, the effect depends on the borer: it worked for the stem borers studied in China, but the rice specialist borers of India, the Philippines, Thailand and Indonesia do not lay their eggs on vetiver, so the trap does not work against them.
Vetiver hedges also shelter beneficial insects, including parasitic wasps that attack sucking insects on coffee and whitefly on vegetables. Vetiver can act as a dead-end trap for some root nematodes too.
Design guidance: D7 GUIDE_STEM_BORERDesign guidance: D6 GUIDE_NEMATODE
Forage
Correctly managed, vetiver is a useful livestock feed, both cut and carried and grazed on site. Timing matters most: young leaves are nutritious, while old leaves are coarse and poorly eaten. Short periods of intensive grazing make animals eat everything on offer instead of picking and choosing. Vetiver stays green in drought; in a recent Australian drought, vetiver cut from a wastewater wetland was baled and trucked to cattle.
Expect about 20–30 tons of dry matter per hectare a year under ordinary conditions, and more only with irrigation and high nutrient supply. Yields vary widely between cultivars. FORAGIKA, a sterile cultivar released by Dr. Umesh Lavania in India, has softer leaves and higher yields. Vetiver forage still needs more research.
Large farms and estates
Large farms use vetiver for the same reasons as small ones. They also use it to protect farm roads, drains, canals and embankments, to treat effluent, and as windbreaks. Savonnerie Tropicale Huilerie de Melville (STHM), a 3,000 ha certified-organic oil palm plantation in Madagascar, introduced vetiver in 2004 to protect its 80 km of drains. It now also uses vetiver on its riverbanks and slopes, and for mulch.
STHM case study (PDF)Pollution and Wastewater: farm effluent
Gardens and landscaping
Vetiver is an attractive plant for gardens, parks and public spaces, in the ground or in pots. It edges paths and roads, beautifies lake and stream banks, makes road dividers that cut headlight glare, and forms a living barrier along cliff tops. While it does this, it also stabilizes slopes, controls erosion and cleans water. Trimmings become mulch, compost or thatch.
In kitchen gardens, rows of vetiver conserve soil and give a steady supply of mulch. Vetiver also makes an effective rain garden for storm water in towns.
Photo essay (PDF)Design guidance: C6 DS-RAINGARDENDesign guidance: D9 GUIDE_KITCHEN GARDEN
Further reading
Photo essays, handbooks, papers and videos on vetiver in agriculture. Type in the search box to filter by topic, country or author. More papers are in the Document Center and the Conference Papers.