Lot enfòmasyon sou anvironman - Vetiver

[ Kesyon Moun Mande Anpil ]

Serge afiche mesaj sa, jou 08 Novanm 2002 a 00:11:28:

Gen kèk semen de sa, mwen te vini ak koze Vetive a sou fowòm lan, kote mwen tap mande poukisa yo poko sèvi ak zèb pou eseye rezoud pwoblèm ewozyon ak anvironman nan peyi Dayiti. Sa telman te anmède mwen mal fe plis rechèch e se konsa mwen jwen yon liv ki enteresan anpil ke yo rele: Vetiver Grass: a thin green line against erosion. Se National Academy Press nan Washington D.C. ki pibliye li.

Map repwodui piba de paj mwen jwen nan liv ki kapab enterese lektè yo anpil e ki vin fè mwen kwè pi janm ke Vetivè, se yon zèb ki kapab yon eleman kle nan solisyon pwoblèm ewozyon nan peyi Dayiti.

Mwen fèk li nan nouvèl ke nan Okay, gen yon izin Vetivè ki boule.

Kesyon mwen toujou rete: Kouman fè pa gen inisyativ gouvènmantal pou sèvi ak zouti sa? Kote espesyalis nan anvironman yo? Mwen pa gen repons pou yo. Mwen ta swete ta gen kèk moun sou fowòm lan ki ta pouse sa pi devan. Men tèks yo ki ekri an angle.

Haiti

Because Haiti is the world's second biggest supplier of vetiver oil, the plant is very well known there. Unfortunately, however, in this country of impoverished soils, it has not been widely employed for erosion control. Its extreme robustness can easily be seen because it commonly occurs on the worst possible sites. Even when people are trying to produce vetiver roots commercially, they usually employ the least valuable ground, much of it so worn out that nothing else can survive.

However, only southern Haiti grows vetiver for oil. In the northern part of the country, people leave it in place and use it for soil conservation. "Vetiver works," notes one admiring Haitian. "The minute you remove it the banks fall down."

A good example of vetiver's abilities can be seen on the road from Port?au?Prince to Cap Haitien. Where it cuts through the hills, the embankments on both sides are lined with vetiver. The terrace effects have successfully stabilized these banks, an amazing feat considering their steepness and erodibility.11

Haitians like several of vetiver's features: it can withstand animals (which eat leucaena, for example), is easy to propagate, is drought hardy, and stays in place with minimum maintenance. Moreover, they point out that people can walk over vetiver without damaging it; doing that to Ieucaena generates a gap.

One widespread opinion that vetiver impoverishes soils has been debunked. Barrenness does occur in some vetiver areas, but hardly because of the plant. The hillsides had first been damaged to the point where farming was no longer possible, then turned over to goats, and only after the goats could find nothing else to eat did the farmers put in vetiver. For such sites vetiver was merely the last straw.

So far, not much vetiver has been used to stop farm erosion.

Men lòt pasaj la sous Vetivè a, toujou nan menm liv la:

Does Vetiver Cause Erosion?

No.

It may seem ironic, but it is nonetheless true that vetiver cultivation is barred from certain parts of Indonesia solely because it "causes soil erosion. " This had led several people to denounce all efforts to promote the wider use of vetiver. After all, they point out, more vetiver is grown for oil in Indonesia than anywhere else except Haiti; surely Indonesians must know the plant and its performance.

Closer inspection, however, shows that the culprit is not vetiver itself but the specific way farmers grow and harvest it there. It is so difficult to dig up the roots that the plants are grown in special sites where the soil is extremely' light. Only there can the farmers obtain the roots with a reasonable effort. When the time comes, they rip the plants out, leaving behind trenches of loose dirt that could hardly be more erodible if designed for the purpose. Some farmers even place their rows up and down (rather than across) the slopes. This allows the rain to scour the land in an even more disastrous manner.

When vetiver hedges are established on the contour and left in place, there is no evidence that they cause erosion.

Is It Safe?

Vetiver is already so well known in so many countries that any serious threatfrom its usefor erosion control would by now be obvious and widely reported. However, there are fertile types in India that could become hazardous if they are distributed.

A major reason for confidence in vetiver's safety is that the plant will seldom have to be introduced anywhere. It is already found throughout the tropics and has been there for at least a century. Apparently it has never spread in an uncontrolled manner or become a major nuisance. Possibly, such difficulties may be found as people investigate this plant more thoroughly, but, by and large, vetiver has not become a problem.

It is important, however, that only the right kind of vetiver be used. The types of South Indian origin apparently produce nonviable seeds and must be maintained by vegetative methods. Luckily, this is the fragrant?root type that has been spread throughout the tropics. In areas where it has been planted for decades, or in some cases for more than a century, it has seldom (if ever) spread from seed. In a few areas vetiver is reported as an escape, but even there it neither spreads rapidly nor is considered a nuisance.

On the other hand, types of vetiver grown from seeds introduced from northern India into the United States in 1989 have formed seeds and have germinated in areas adjacent to small plots in Georgia. This fertile type should not be introduced to new areas. It has long been used to protect canal banks in irrigated agriculture in northern India and the neighboring Terai of Nepal without becoming a pest or spreading uncontrollably from seed. Nonetheless, at this time, because of its potential hazard, only vegetative materials should ever be planted.

Vetiver must never be propagated from seed.



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