Without soil and water there will be no photosynthesis and no life on this planet. Both are becoming degraded and in short supply globally — Vetiver Grass Technology (VGT) can improve both and deserves government focus and support.”
agriculture, climate change, erosion, forage, plant, slope stabilization
Arbuscular mycorrhizal fungi: AMF have an important role in the growth of vetiver and we are seeing increased use of vetiver by permaculturists for all sorts of purposes including its planting within stands of other crops and sometimes very close to young plant seedlings such as papaya, mango, dragon fruit. etc with what appears to be positive growth benefits (linked possibly to moisture and AMF). This begs the question as to differentiating between vetiver cultivars on the basis of root architecture for this purpose and are some cultivars better at hosting AMF.
Leaf and stem density: Although the roots are important, particularly as a stand alone plant, the leaf and stem density as well as the total mass, play an important role when vetiver is used as a conservation barrier to trap sediment flow to disperse concentrated water flows across and behind the vetiver barrier, and reduce flooding … These same barriers have a use as a source of forage, thatch, mulch etc. High leaf density and mass in vetiver generally is reflected in its tillering capacity and root mass. Deeper rooted plants also are better at recycling soil nutrients and better growth under dry conditions. We have noticed that once users understand the multiple benefits of vetiver they are more receptive to using the plant for soil conservation. Also deeper rooted plants can punch through soil pans and the impediments thus enabling ground water recharge (by as much as 4 times) from the spread out rainfall runoff temporarily trapped behind the barriers — reflecting a secondary but important benefit of vetiver barriers.
Root digging: We have in the past been concerned about the potential of vetiver hedgerows being dug for the oil. In reality it is rarely a problem and we virtually never receive feedback that it occurs. Most vetiver that is planted for oil (VPO) is planted on lighter sandier deep soils that are easy to dig (often on flat land) – on the other hand most vetiver grown for soil conservation or slope stabilization is grown under conditions and soil types that make digging difficult and uneconomic. Where VPO is planted on sloping land and where the digging process can result in erosion, farmers need to incorporate permanent vetiver contour barriers to protect the VPO crop. This message needs to be passed on to these farmers (as is being done now in Haiti).
Vetiver type for oil: My impression (and I stand to being corrected) is that from what I have seen in the field and from many photographs that have been posted on line is that the VPO types appear to be sturdier, bulkier, taller and more dense than some of the other types, and that the triploid/polyploids used for oil originating from south India would appear the sturdiest. Thus, as long as the plant is sterile why not use the VPO for environmental purposes. One big advantage of this would be that VPO producers could become integrated with the “not for oil” vetiver users thus providing a secondary income for oil producers (very useful when there is an oversupply of oil and oil prices are low) and what should be a very low cost source of plant material for other users. (planting slips would be low cost as they would be a byproduct of VPO harvesting and the potential supply is very high). Assuming we can discount the “digging” aspects as a problem then can we narrow the vetiver types to a few that are multipurpose includes quality oil, deep roots, good host to AMF, and sturdy and dense stems and leaves.
Vetiver types generally: Other aspects that are becoming important include (a) salt tolerance – especially for coastal stabilization (b) insect habitat and pest control – Chinese are now using vetiver as a dead end trap crop for rice stem borer control and as a habitat for beneficial insects such as parasitic wasps — I wonder if there are any differences between vetiver types as to their attractiveness and “killing” of insects such as stem borers — (c) fire tolerance – with increase in wild fires are there types of vetiver that are more resistant to fire, (d) decontamination of polluted soil and water, and (e) cold tolerance – increasing demand to use vetiver under very cold winter hot summer climatic regimes. The Chinese claim that have identified types that perform better and survive cold (freezing) conditions.
Barriers deterring the use of Vetiver Grass. (1) Some research shows that farmers need to be financially supported to undertake soil conservation works. – seems to work in the US in various forms but not in poor countries. Poor country conservation has generally come through World Food Program “food for work” programs and bilateral and multilateral aid agencies, or heavily subsidized programs where there is no incentive for farmers to maintain their works and where there are huge opportunities for corruption by officials at all levels (2) engineered design based systems are generally preferred by “officials” – a bigger budget line – more room for corrupt practices and more control by involved officials. (3) biological systems are generally not preferred by engineers as most have not been trained in such aspects. They are also much lower costs and less opportunity for corrupt practices. (4) In most developing countries soil conservation is the responsibility of a “Soil Conservation Department” most of these are focused entirely on soil conservation and rarely consider the wider and secondary aspects that are derived from the primary work. Thus when introducing (perhaps reluctantly) a technology like Vetiver Grass the conservation agents are either generally unaware of the many secondary benefits or do not tell the end user what those benefits may be. This all adds up to low adoption rates (5) In this age of “global environmental threat” primary and secondary schools should have a curricula that includes a compulsory class on basic environmental principles. — in other words some serious thought needs to be given to environmental education.
Research . There are plenty of opportunities for vetiver research in many areas of application. Vetiver research needs to be better coordinated. Such research should be multi-sector driven and not just the responsibility of the agricultural sector. Vetiver in its many applications could prove a very valuable a tool to mitigate many soil and water issues relating to climate change. A good case could be made to the World Bank and others to support such research
Policy: With 35 years of global research, development and experience to call on there is an opportunity for Government agencies to set out a clear policy directive on the use and development of Vetiver Grass Technology (VGT) in all aspects.
VGT is a proven success, is low cost, and applicable for a wide range of applications under a wide range of conditions. What more does one need!