Piet Sabbe has been using and promoting the application of vetiver for soil and water conservation since 1997. On his own farm in Ecuador the impact of vetiver hedgerows has been significant …. “In order to have a good showcase for the use of Vetiver, I created vetiver induced terracing on my farm, combining citrus trees and pineapples with Vetiver hedges at an interspace of 6 to 7 meters. o Within a couple of years, the effect was clearly visible and measurable: run-off had stopped and the amount of organic matter increased from 0 % to 3 %. The citrus trees produced abundant Tangelo and Lemon. Also, I planted a couple of hectares of pure Vetiver grass for production and business.” He has some interesting insights as to the problems of introducing vetiver to small farmers, but more recently has had good success with farmers who practice permaculture and are interested in agro-ecology.
Soil Erosion continues to be a serious problem, and as population growth expands and land resources are more intensively used (and misused). Soil erosion results in loss of land, reduced soil fertility, greater rainfall runoff, lower groundwater recharge, increased sediment flows in rivers, lowered quality of drinking water, increased flooding, and diminished economic benefits. The result is increased hardships to both rural and urban populations especially in developing countries. Vetiver Grass Technology provides a very low cost and effective solution on controlling sediment losses from farm land and other eroding slopes.
How does it work? — Of the many attributes of vetiver that makes it such an effective soil conservation teghnology there are some that are critical: (1) a deep root system that binds the soil to great depth (2) it is a very stiff plant that remain standing against relatively deep water flows (3) being clonal, vetiver plants can grow closely together so that when planted as a hedge along an average (allows for some straightening) contour line, the hedge creates a very tight filter barrier that (a) slows down the flow of rainfall runoff bringing velocity of runoff at the hedge barrier to near zero, and (b) traps sediment carried by the runoff on the upslope side of the hedge. Over time these depositions increase and the slope gradient becomes less, further slowing the velocity of run off and the related erosive processes. Vetiver continues to grow and maintains effectiveness as these natural terrace risers gain height.
If applied correctly the Vetiver System can be an important tool to reduce erosion by up to 90% (with variability according to soil and climate). Reported soil loss reductions of over 100tons/ha have been reported (CIAT, Colombia).
The following guides may be helpful in developing plans for the use of vetiver grass and its applications for watershed and farm planning
Contour farming and soil and water conservation — A modified sight leveling device and how to survey contour vetiver hedgerows
How to create a contour line overlay layer for Google Earth Pro.
Slope, Surface Run, and Vertical Interval
| Slope degrees
1 |
Slope percent
1.7 |
Gradient
1 in 57.3 |
Surface Run (a) meters
57.3 |
The figures for the surface run are based on a vertical interval (VI) of 1 meter. To use this table, multiply the surface run by the VI: for example, with a VI of 2 meters on a 70 percent slope, the surface distance between vegetative barriers = 2 x 1.7 = 3.4 m
Over the past 30 years much research has been undertaken that demonstrates that vetiver grass when grown as a narrow hedgerow on the contour is one of the most effective erosion control technologies available to farmers, especially small farmers, gardeners and other small scale growers. A lot of this is documented on this website in the form of research papers and also referenced under “Newsletters and Posts“
Below are listed some useful links to supporting documents:
Introductory Photo essay “Vetiver System for Soil and Water Conservation” Vetiver Guides and Manuals
Comparing constructed contour banks with Vetiver hedges
Early research on the effectiveness of vetiver for erosion control can be found in a series of TVNI newsletters TVN NEWSLETTER INDEX (vetiver.org) published in the 1990s. A recent news letter references this early research at this link. Since then more research has been undertaken some of which can be found in the Document Center – VETIVER GRASS SYSTEM ARCHIVES – SOIL AND WATER CONSERVATION APPLICATIONS OF VETIVER
There are a number of guides and manuals – the most practical and useful one, for small farmers in particular, is John Greenfield’s “The Vetiver System for Soil and Water Conservation” Vetiver System for Soil and Water Conservation.pdf Others can be found at this link.
Multiple Benefits of the Vetiver System and its Environmental Application in Ethiopia Dr. Belay Simane Feature_article-_Vetiver_System_3
Introductory Photo essay “Vetiver System for Soil and Water Conservation”
| Vetiver System: Ethiopia – Soil and Water Conservation. (movie) |
| Vetiver System: Ethiopia – Hassan Ali – Vetiver System Farmer of Excellence. (movie) |
| The Vetiver System – “key technology” for East Bali Poverty Project in Indonesia. VIDEO This video, produced by Sarah Matthews of Saffyshine Production as part of a Brock Initiative and the East Bali Poverty Project, is a training video that shows how the Vetiver System is a vital component of the East Bali Poverty Project and how it has had an impact on children and their families. The video (32 mins) includes animations, film and narration by people intimately connected to the project. The narration is in Indonesian with English subtitles. |
| Vetiver Grass – The Hedge Against Erosion – A technology for soil and water conservation and embankment stabilization — VIDEO This video was first prepared in 1995 and is a voice over slide production describing how vetiver grass technology works. Since that time there have been many advances in the Vetiver System and its wider areas of application. However the basic technology remains very much the same, and the video provides a useful entry point for a new user. (28 mins) |
| Best Practices in Natural Resource Management – Multiple Uses of Vetiver Grass — VIDEO This documentary shows how 17,000 Ethiopian farmers used the Vetiver System to halt erosion, increase crop yields, reduce insect damage, improve ground water and rehabilitate degraded wetlands. Additional uses included thatch, forage, and for important social functions. The technology is spreading to farmers in adjacent districts. The documentary was funded by Swedish SIDA. |
| COMPTABILITE NATIONALE ET PROJETS ENVIRONNEMENTAUX : CAS DU PROJET VETIVER AU MALI by Claude NJOMGANG & Abdoulaye TRAORE |
| L’utilization de Vetiver dans l’agriculture et El’arboriculture An excellent french translation that overviews the vetiver system’s many practical uses. Read More |
| The Vetiver System for Soil and Water Conservation: Download the Vetiver System for Soil and Water Conservation, a complete handbook on how VS can be used for erosion control. This book is a modification of John Greenfield’s “Vetiver Grass – A Hedge Against Erosion” and contains colored images to match the original line drawings that depict detailed application of the technology. Hard copies may be purchased from Amazon.com |
| Rural Poverty Alleviation and Natural Resource Protection in Minority Mountains of Guangxi Province of China: The EED funded Vetiver and Agroforestry Technology for Rural Poverty Alleviation and Natural Resource Protection in Minority Mountains of Guangxi Province of China has been launched. The project aims at helping local farmers develop economic trees for 48700 seedlings and 40 mini-irrigation systems. Meanwhile, vetiver system and agroforestry technology will be introduced and over 3 million vetiver tillers will be planted in order to conserve nature resources and provide farmers with multiple products and materials. Besides, various training courses will be organized and different publications will be produced and widely distributed to extend the project. Learn More |
| Vetiver Grass A Hedge Against Erosion. John Greenfield’s Farmers handbook French Edition |
| New Vegetative Approaches To Soil and Moisture Conservation. Magrath, Greenfield and Yudelman |
| Disaster Mitigation, Flood and Erosion Control in Haiti Short paper by Mike Benge. Senior Agro-Forester |
| El vetiver como componente del manejo sostenible de los suelos en ecosistemas frágiles de Cuba Autores: Claro A. Alfonso, Eduardo A. Cabrera y Pedro Porras. Instituto de Suelos de Cuba. See more… |
| Machine Planting of Vetiver in Australia Nurseries were planted under Paul Truong’s supervision using mechanical planters. See… |
| Some Vetiver related works in Ethiopia Ethiopia’s Sustainable Land Use Forum (SLUF) has been promoting VS in Ethiopia for some years. Here are some photos of its use. See |
| LE SYSTÈME VETIVER A new handbook for Haitian users – a modification by the WINNER project of “Vetiver Grass – A Hedge Against Erosion” includes photographs. Read more … |
| Vetiver The Proven Soil Conservation Technique A Training Manual for Communities and Field Workers This manual was created by the University of the South Pacific to help train people concerned with remediation of sedimentation of coral reefs |
| Farm Level Economics of Soil Conservation Practices in The Zomba Rural Development Project of Malawi This interesting study by Julius H. Mangisoni covering 450 farmers indicates farmer preference for the Vetiver System. The Net Present Value Model has demonstrated that vetiver bunds are the most profitable and effective methods of combating soil erosion. The effectiveness of the vetiver bunds lies in the fact that they combine two technologies (bare contour bunds and vetiver grass) and the vetiver grass has an excellent rooting system. |
| Sistema Vetiver(SV) Controle da Erosao e Sedimentacao & Estabilizacao de Taludes (Com referencia especial a Rodovia Ho Chi Minh ,no Vietnam) Por Dr.Paul Truong (*) e Dr. Paulo R.Rogerio(**) |
| Some Vetiver related works in Ethiopia A thoughtful and interesting paper on the growing application of the Vetiver System in Ethiopia for environmental improvement. |
| Rural Development and Environmental Protection in the Dabie Mountains of China — New Project launched A new project in the Dabie Mountains of China under development. Protection of irrigation ponds with vetiver, and vetiver handicraft training. China Vetiver Network and Liyu Xu |
| Evaluation of Nutrient Trapping by Vetiver Grass: In Soil Eroded Area of Anno Agro Industry Farm, Gobu Sayo district, East Welega Zone, Oromia Regional State, Ethiopia [Paperback] Abdisa Gesesse Wayuma (Author) This book, available at amazon, showed that Vetiver Grass has significant impacts on soil conservation and nutrient trapping. It improves most of the soil physicochemical properties and soil productivity due to the fact that vetiver plants form hedges or a living porous barrier, which slows and spreads runoff water and traps sediment. And the author recommends that vetiver grass system is an effective soil conservation system in trapping nutrients at low cost and the use of vetiver grass is recommended as an affordable and sustainable soil management practice to improve soil fertility. |
| Erosion Control Using Modified Soils Paper by James T. Kidd, Chung R. Song and Wongil Jang relating to erodibility of vetiver protected soil from plunging water flows |
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Evaluation of Vetiver Grass Buffer Strips and Organomineral Fertilization for the Improvement of Soil Physical Properties Interesting and useful Nigerian research by: Effiom Oku, Olajire Fagbola and Paul Truong Vetiver System for Erosion and Sediment Control by P.N.V. Truong and R. Loch |