CV Akar Wangi Jaya
VETIVER GRASS ROOTS OF STABILITY ; Practical solutions to sustainability challenges
Rapid adaptation to the consequences of climate change will become an urgent focus of aid and development programs. Under global warming, maintaining food production and water supplies will be two of the most urgent and difficult challenges. In arid lands, water scarcity is worsening. Harvesting rare, intermittent rainfalls, while, protecting farm soils from erosion are the main priorities. In arid zones, every drop of scarce rainfall must now be harvested. Although dams and water tanks have their place, in general, the only practical way to store rainfall is, as soil moisture, in the soil.
Soil & organic particles accumulate behind vetiver hedges so well that by capturing runoff vetiver hedges also prevent excessive soil erosion. Vetiver hedges are proven to solve two of our biggest resource management challenges at once: They conserve rainwater & they conserve soils. Vetiver is an economic solution for two of the biggest problems in (warm climate) land management worldwide.
The key to harvesting stormwater runoff is retaining it on the land long enough for it to percolate into the soil. Vetiver, planted in contour hedges, retains and harvests rainfall by retaining runoff, allowing it to percolate into soils. In wetter regions, annual rainfall is being concentrated into more extreme storm events. In areas with higher rainfall, vetiver
contour hedges harvest rainwater from storm events, while dramatically reducing soil erosion at the same time. Widespread establishment of vetiver hedges, on sloping and flood-prone farmland, will quickly and effectively mitigate against increasing water scarcity and the increasing concentration of annual rainfalls into more extreme storm events.
CIAT, in 2002 estimated that deep rooted South American grasses sequestered between 100 to 500 tons of Carbon per ha per year.
Vetiver would sequester probably more. Lets take an average of 250 tons of carbon per year.
This would mean that at a density of 100,000 plants per ha vetiver would sequester 2.5 kg carbon per plant.
Thus every linear km of vetiver hedge (8 plants per meter) would sequester (8000 x 2.5 kg) 20 metric tons of atmospheric carbon per year. A linear km of vetiver hedgerow is equivalent to 2000 fast growing poplars in carbon sequestering terms.
Your “carbon foot print” could be negated by planting 50 to 60 vetiver plants in a tropical country or approximate 8 meters of vetiver hedgerow.
Vetiver grass is a ‘soft’ engineering solution. Vetiver is planted to protect slopes, banks and cuttings. Vetiver is environmentally, technically and economically superior (in appropriate situations) to ‘hard’ engineering solutions. Vetiver is ‘green’, permanent and economical. Vetiver, bio-engineering for the 21st century.
IN WETTER REGIONS
In wet or wet/dry tropical regions, soil erosion, nutrient leaching & rapid drying of carbon-deficient soils are root causes of poverty & poor agricultural production. Vetiver hedges conserve soils & nutrients while increasing soil moisture & soil-carbon levels. Vetiver hedges can increase agricultural production & alleviate poverty.
BIO-ENGINEERING for INFRASTRUCTURE PROTECTION
- Stop excessive soil erosion, vetiver planted on slopes, banks & cuttings is a permanent solution
- Permanently stabilize roads, vetiver planted on banks & cuttings
- Landslide protection, vetiver planted on unstable slopes will reduce rock falls and landslips
- Vetiver protects causeways & floodways
SUSTAINABLE SEWAGE /WASTEWATER /SANITATION TREATMENT
- Vetiver in Sewage Treatment, vetiver is ideal for sewage & wastewater wetlands and vegetated leach fields, vetiver roots are an excellent filter for wastewater outfalls and landfill leachates
SUSTAINABLE LAND MANAGEMENT
- Sustainable farming on slopes, vetiver contour hedges, ‘the best solution for soil erosion’ according to the definitive series, The Ecology of Indonesia.
- Stabilize eroding riverbanks, vetiver is more economical than gabions, vetiver will reduce sediment loads from run-off, vetiver improves water quality, reduces nutrient loads & risk of eutrophication
- Stabilize & protect storm water & irrigation canals, vetiver leaves will filter sediments and rubbish. Vetiver roots filter soluble nutrients and chemicals
- Aquaculture ponds and access paths can be stabilized with vetiver grass
- Fencing, mature vetiver, if combined with fencing wire, is an effective barrier against livestock
- Dewatering soakage areas, vetiver roots improve percolation
What is vetiver:
Latin name: Crysopogon zizaniodes, is in the grass family. It is a clumping grass, which produces new young plants around the perimeter of the clump (seeds are mainly sterile)
Vetiver can be used to:
- Harvest Rainwater – vetiver hedges intercept and retain overland flows (storm runoff) and significantly increase soil-porosity in the root-zone
- Protect Infrastructure – road shoulders/cuttings/banks, causeways, bridges, pathways, canals, drainage systems Protect Structures – stabilizes unconsolidated banks and cuttings, mitigates flood damage
- Protect Coastlines – barrier to wind blown sand, grows well in the littoral zone
- Protect Waterways – stabilizes riverbanks, improves water quality (reduces sediment loads) by filtering run-off Stabilize Sloping Land – permanent bioengineering solution against sheet erosion, gully erosion and landslides
- Protect Flood-prone Land – slows down overland flows, traps sediments
- Protect Farmland – stabilizes slopes, riverbanks and flood zones, does not compete with adjacent crops, vetiver is non-invasive
- Sequester Carbon – creates a permanent, massive root system comprised mainly of carbon. Estimates of carbon sequestration have been made, see http://www.vetiver.com
- Facilitate Reforestation and Plantation Establishment – increases survival rates and promotes rapid growth of tree seedlings
- Treat Liquid Wastes – nutrient removal via massive, fibrous root system and rapid biomass production, removes other pollutants including some heavy metals in leachates
The World Bank recognized the benefits of Vetiver grass many years ago. It has been actively supporting the use of Vetiver via funding for field projects and support for The Vetiver Network for many years. Other large development agencies have funded vetiver projects eg. USAID and GTZ et al.
There are Vetiver projects in many countries throughout the tropical and sub-tropical world including Australia, China, Vietnam, Indonesia and several countries in South America and Africa. Complete information is available from: The Vetiver Network. http://www.vetiver.com
Assessing Environmental Risks:
- Vetiver sets sterile seed, it does not invade surrounding areas
- Vetiver does not have stolons, it does not spread into adjacent areas
- Vetiver requires sunlight, it does not grow in vegetated or forested areas
- Vetiver roots grow vertically straight down, it does not compete with adjacent plants
Assessing Environmental Benefits:
- Vetiver, in contour hedges or blanket plantings, stops or significantly reduces sheet and gully erosion
- Vetiver hedges can significantly reduce sediment loads in waterways by trapping sediments in runoff and overland flows
- Vetiver plantings can reduce nutrient loads in ground and surface waters eg leachates from landfills, septic tanks
- Vetiver, in sewage treatment systems (subsurface flow wetlands and leachfields) removes nutrients (and some other pollutants) from wastewater
- Vetiver can facilitate more successful reforestation or plantation establishment. (Note: Once trees have formed a closed canopy and erosion control is no longer necessary, the vetiver will die out)
From the many thousands of native plants and animals available to us, only a very few can successfully be used in agriculture. The same is true about plants for use in environmental management. Many plants have some of the required characteristics but vetiver is unique in the combination of benefits it provides without causing any negative side effects.
CV. AKAR WANGI JAYA
CV. Akar Wangi Jaya is a registered Indonesian privately held company.
We provide local and international expertise on Vetiver, and we have our own research and development facility which we share with the local university for education purposes.
- Fencing (also land management): improving poor fencing by integrating close-planted vetiver
- Farming Small Crops: vetiver fencing for a vegetable farm, demonstrate that vetiver does not compete with nearby crops plants
- Wastewater Treatment & Disposal: vetiver in a household, sewage & wastewater treatment system, vetiver is planted in a leach field
- Flood-Zone Land Management: vetiver hedges will trap silt under flood conditions reducing soil erosion and sedimentation in waterways
- Freshwater-well Protection: vetiver planted around a well to filter pollutants from surrounding soils
Our Vetiver plantations are located in Aceh and we supply Vetiver plants with a current stock of over 500,000 ready to go plants.
In addition we provide consulting and planting services to our clients.
Post-Tsunami reconstruction in Aceh:
American and British Red Cross’s – on-site sewage treatment systems for 2,000 houses in Aceh Jaya
Sewage and Wastewater Treatment by Vetiver grass
BIOLOGICAL TREATMENT SYSTEM
SEWAGE AND WASTEWATER TREATMENT
Although the major focus in sanitation has been on preventing human contact with fecal coli forms and other pathogens by far the major pollutant in sewage and wastewater is nutrients. Effective treatment systems will not only separate people from disease carrying organisms, they will also harvest nutrients out of sewage and wastewater.
HOUSEHOLD ON-SITE TREATMENT SYSTEMS
Poor, or non-existent, sanitation and its corollary, lack of safe drinking water are the biggest causes of sickness and disease in the tropical developing world. Urban communities may eventually be served by centralized sewage systems, but in rural areas, where centralized facilities are out of the question, there is an urgent need for low-tech, low-cost household treatment systems.
Recently, perhaps for the first time, biological treatment systems using plants to harvest nutrients have been installed on a large scale. Subsurface flow wetlands and/or vegetated leach fields are currently being installed in thousands of rural homes under reconstruction in tsunami-affected Aceh.
Vetiver grass is being widely used in wetlands and leach fields in Aceh for two main reasons.
Firstly, although wetland plants, reeds, rushes and cattails, are usually recommended, Acehnese living in wetland environments view these plants as invasive weeds and as such they are not acceptable in household gardens.
Secondly, vetiver has the desired characteristics needed in biological treatment systems. It has a massive root system, which effectively harvests nutrients, it produces biomass quickly and it can live in high moisture and nutrient rich environments.
Danish Red Cross – dyke reconstruction in Aceh Jaya
USAID – Pilot: communal sewage treatment system for 18 houses in Lhok Nga, Aceh download
GTZ – High School sanitation system, SSF wetlands and vetiver leachfields, Cot Aron, Banda Aceh
CV Akar Wangi – Pilot: riverbank stabilization in Darussalam, Aceh
Handicap International – on-site sewage treatment systems for 300 houses in Lhok Nga, Aceh
International Federation Red Cross Crescent – sewage treatment system at Head office, Banda Aceh
Swiss Caritas Aceh – Vetiver used to stabilize collapsing flood control drainage system and reduce wastewater pollution
Road stabilization and sediment trapping on a frequently flooded passage
Fish Pond stabilizing for flood-prone areas
Very steep slope stabilizing, after 6 months permanent stabilized
Oberoi Hotel Bali – large wastewater leach fields to protect nearby river and beach
Riverbank stabilization near university before, planting and 6 months after
Jantho district hospital in Aceh Besar – design and completion of external premises
ROAD DAN INFRASTUCTURE
Stabilizing slopes, cuttings and banks with Vetiver grass
The stabilizing structure on an unconsolidated slope may be retained by gravity and/or secure anchorage. Ideally, anchors are attached through the unstable surface into a stable substrate. On compacted fill, the surface structure will ideally be anchored deeply into the fill material.
The surface of the slope, bank or cutting must be very durable, able to withstand extreme weather or flooding events for many years into the future with little or no maintenance.
Conventional or ‘hard’ engineering solutions are expensive and resource intensive. Contractors implement the projects, often using cheap foreign labor and heavy machines. Large quantities of fuel are used transporting bulk materials to the site. Overall, these projects have a significant Greenhouse footprint and provide few work opportunities to local communities.
‘Soft’ engineering or Bioengineering employs plants with specific characteristics suited to the task at hand. Vetiver grass is unique in the number of benefits it provides without any significant drawbacks.
Benefit of Vetiver Grass
- A permanent, low maintenance solution: Vetiver grass is a perennial plant, which provides a permanent solution with little or no maintenance
- Strong anchors are spread evenly over the stabilized area: The vetiver root mass is very large and the fibrous roots are very strong
- Deep anchorage: Vetiver roots penetrate several meters into native soil or fill material
- A durable surface: Vetiver foliage is tough, it survives fire and extended flooding
- Stops soil erosion: The dense foliage traps soil particles being washed downhill
- Improves water quality: Sediments are trapped by foliage before entering nearby waterways
- Water harvesting, flood mitigation: Vetiver greatly increases percolation rates
- Supports local economies: Vetiver projects are labor intensive. They employ locals, especially in rural areas
- A ‘Green’ solution: Vetiver is more natural and more attractive than stone or concrete
- Side-benefits: Vetiver foliage may be harvested for thatching, fodder, composting or other purposes where biomass is required
- Vetiver is non-invasive: It sets sterile seed and does not have running stolons
- Vetiver is non-competitive: Roots grow vertically downwards, vetiver does not compete with adjacent plants
- Safe from pests and disease: Vetiver has been shown to have very few pest or disease problems
- Precedents: Vetiver has been proven in many projects in many countries around the world. Vetiver has been promoted and supported by the World bank for many years
Vetiver Contour Hedges
Insufficient soil moisture is the main limiting factor in agriculture in many parts of the world and Global Warming is exacerbating the problem. In many places, although there is sufficient rain to grow crops, rainwater, especially in storm events, runs off quickly before it can percolate into the soil profile.
Small crop agriculture typically exposes soils between the beds, in the beds before planting and in between the crop plants. In areas practicing dryland grazing soils are exposed between sparse grasses and weedy plants.
Soil is exposed between sparse grasses on a slope. Soil is eroding quickly. Most rainwater is running off. (Aceh, Sumatra)
Topsoils exposed to rainfall erode quickly but they also tend to form crusts as larger particles (soil colloids) are smashed into fine particles by raindrops.
In places that experience heavy storms, topsoils on grassed or unvegetated slopes are lost very quickly. Flooding on flat unvegetated land also carries away vast quantities of topsoil. Lack of fertile topsoil is a major limiting factor in agriculture.
Reducing soil erosion and increasing soil moisture levels are urgent priorities for agriculture in the developing world.
On slopes physical barriers are required to retain topsoils and hold rainwater long enough to allow for percolation. In flood zones, permeable barriers are required to slow water velocity and trap sediments.
Vetiver Grass Countour Hedges
Water harvesting contour hedges must be horizontal. Sloped hedges will act as drains, carrying water away rather than holding it back.
Vetiver grass, planted closely in contour hedges, traps eroding topsoil and holds back stormwater runoff allowing it to percolate into the soil profile. The massive, deep root systems of the vetiver plants also facilitate percolation. Established vetiver plants survive prolonged drought and will regenerate after fire.
Vetiver grass, planted in hedges perpendicular to overland flows, slows water velocity while the dense, fine-leafed foliage traps sediments. Established vetiver plants can survive flooding for weeks.
A Permanent Solution
Vetiver contour hedges are a permanent and durable solution to soil erosion. Vetiver contour hedges continually harvest rainwater over the years. Vetiver hedges perpendicular to overland flows permanently mitigate against soil erosion in flood zones.
Vetiver grass is non invasive, it does not produce traveling stolons and it sets mainly sterile seed. Vetiver roots grow vertically downward, importantly, it does not compete with adjacent crop plants.
Vetiver will not grow in shade. If reforestation or plantation establishment is the ultimate aim the (no longer required) vetiver will slowly die out as the tree canopy closes.
Vetiver has been proven in many projects, in many countries, worldwide. The World Bank has been promoting vetiver via field projects and The Vetiver Network for many years.
Large areas require large numbers of vetiver plants. Vetiver plants are produced commercially, by government agencies and NGO’s.
As a rough guide, bearing in mind that plantings must be designed specifically for each location, vetiver planted at 5cm spacings requires 20,000plants for 1,000m of hedges. Costs and prices will vary according to several factors but economies of scale will likely be the major influence.
Riverbanks play a critical role in water quality and sedimentation in waterways.
The riverine zone is critical wildlife habitat if vegetated and it provides a vital corridor between otherwise isolated pockets of biodiversity.
Un-vegetated riverbanks collapse during high flows. Waterways become wider and shallower. ‘Hard’ engineering strategies are stone masonry, gabions, riprap and concrete armoring. These strategies retain riverbanks although they do not mitigate against sedimentation or provide habitat for wildlife.
‘Soft’ engineering, or bioengineering, uses appropriate vegetation to retain riverbanks, it is less expensive and provides multiple benefits. Appropriately vegetated riverbanks intercept sediment in overland flows dramatically improving water quality in waterways.
Globally, riverine zones are one of the most important and one of the most endangered ecosystems. Farmland is lost and infrastructure is threatened when riverbanks collapse. Sedimentation of waterways impacts on water quality and exacerbates flooding. Re-vegetation of riverbanks is therefore one of the most valuable strategies to be employed in sustainable land management.
Only plants with deep root systems can effectively anchor riverbanks during high flows. Trees with deep taproots provide deep, but isolated anchors.
Effective protection requires coverage by plants with deep but fibrous root systems. This dramatically reduces the available choices of suitable plants.
The diagram above shows different management strategies for stable riverbanks.
If re-vegetation to a natural state is the aim a diverse suite of native plants and trees will eventually provide good protection although these plantings are extremely vulnerable to high flows during establishment, which may take several years. An interim strategy, which secures the area during establishment, is highly desirable.
Vetiver grass, inter planted with native species, will secure the area while it becomes established with the desired suite of local plants and trees. As the
natives form a canopy the vetiver will slowly die out as shading increases. Over time, vetiver will remain only in those areas not shaded out by other plants.
If simply stabilizing the banks while retaining maximum space for agriculture or infrastructure is the aim, vetiver grass is the most space-effective solution. In engineering terms, it is permanent and durable. Vetiver has the added advantage of acting as a filter of overland flows, reducing soil erosion and subsequent sedimentation of waterways.
Even in the absence of native species, vetiver is a more natural and more aesthetic solution than hard engineering. Vetiver is less resource intensive, not requiring large quantities of rock or cement and the transport costs they incur.
Establishing vetiver is labor-intensive providing significant work for locals, especially in rural areas. Riverbank stabilization projects using vetiver are more likely to benefit local communities rather than large contractors.
It is important to note that although deemed a ‘soft’ or ‘green’ solution, vetiver plantings must be designed, planned and implemented with the same
disciplined approach used in conventional engineering. Spacing and other design elements must be strictly controlled and adhered to in implementation.
A practical establishment regime must also be planned, funded and executed.
Once vetiver plants are established no further maintenance is usually required.
With Vetiver Grass
- Agricultural soils could sequester carbon
- Vetiver Roots sequester carbon
Sequestering carbon in agricultural soils
Modern agriculture, especially in the tropics and sub-tropics, has largely ignored the importance of maintaining soil carbon or humus levels. Soil carbon is vital for the maintenance of fertility and greatly improves retention of moisture. Developing sustainable agriculture in warm climates will require a strong focus on soil carbon levels.
If broad commitments are made to building and maintaining soil carbon levels in farmlands very significant amounts of carbon will be sequestered in the process.
Soil carbon is present mainly in top soils. It is mainly top soils that are lost to erosion most especially in heavy rains. A range of strategies, including incorporation of crop residues, can build soil carbon levels, however, these levels can only be maintained if erosion of top soils is arrested. Foliage from vetiver hedges may be harvested to build soil carbon.
Loss of topsoil seriously threatens agricultural production in many parts of the world. Topsoil erosion occurs mainly on slopes and in flood zones. Most erosion occurs during storm events. Storm events are predicted to increase in intensity and frequency as a consequence of global warming.
Vetiver hedges, more than any other single strategy, have the proven capacity to dramatically reduce soil erosion on slopes and in flood zones.
On Slopes: Vetiver is closely planted in contour hedges, which trap eroding top soils and harvest rainwater. Over time accumulating top soils build fertile terraces behind the hedges. Hedges are spaced according to the steepness of the slope and other site-specific factors. Vetiver survives drought and fire.
In Flood Zones: Vetiver is closely planted in hedges perpendicular to overland flows during flooding. Vetiver’s strong, dense foliage reduces water velocity and traps sediments reducing soil erosion and sedimentation of waterways. Vetiver survives immersion for several weeks.
Carbon sequestration in vetiver roots
Vetiver grass produces a massive and very deep root system. Precise methodologies to quantify the amount of carbon sequestered in vetiver roots are not yet available, however, it is clear that the enormous root mass does store impressive quantities of carbon in the ground.