Vetiver Grass
Technology (VGT) for engineering
purposes.
Leesburg, Virginia. November 6, 1999 I am just back from two and a
half weeks in south China attending a
workshop organized by Liyu Xu, the
Coordinator of the China Vetiver Network
(CVN), for highway engineers. It was a
great experience working with him and
Paul Truong (Australia ) and Diti
Hengchanovich (Thailand). More than half
the time was spent visiting sites in
Jiangxi, Fujian and Guangdong Provinces
that have been stabilized with VGT. Read
Liyu Xu's report for
more detail.
During the past few
years China has added over 30,000 km of
major roads to her inventory. Many of
these are in the south of the country.
Apart from the great length these
highways often pass through rugged
terrain involving massive fill and cut
engineering. It is estimated that over
80% of the point source erosion comes
from these and other infrastructure
developments in China's south eastern
provinces. As a result there are huge
stabilization and re-greening problems to
deal with. The normal Chinese approach is
to stabilize with local grasses (that are
not deep rooted) and or use stone
masonary to face the cut and fill. Linked
to this construction are large and
unrehabilitated stone quarries that add
to sediments flows and remain an
environmental eyesore.

This is a typical
scene in the mountains of Fujian and
Jiangxi -- cut and fill slope unprotected
and eroding fast. Near by is a failed and
costly effort to protect the slope with
concrete.


Above left: a fill
slope planted to vetiver in October 1997.
Now fully stable.
Above right: A fill
slope planted to vetiver in March 1999 (8
months old). Note the large sediment
deposits below the wall that are sourced
from adjacent unprotected areas.
Below right: Vetiver
at over 2 meters after 8 months planted
on very unstable fill embankment
Below left: 20,000
sq meters of vetiver planted in October
1999 on the cut slope of a super highway
(World Bank financed) near Fuzhou,
Fujian. Virtually 100% survival rate from
bare rooted planting.
Over the past three
years the highway departments of the
provinces have been testing VGT and the
results are convincing and impressive.
In Guangdong a cut and
fill slope on a highway near Guangzhou
planted by Xia Hanping in 1996 is now
fully stable. Vetiver was interplanted
with Acacia mangium seedlings.
These trees are now over 20 ft high and
the area has been turned into a dense
woodland. Most of the vetiver has been
shaded out. But it did its job in
providing initial stabilization and a
better environment for the trees to grow.
As a result of this
work and other work it appears that there
is lot of opportunity to expand the use
of VGT to highways throughout south
China, and to use it for the reclamation
and re-greening of the many quarries that
have been opened to supply materials for
the massive construction program that has
taken place in China since the market
reforms were initiated.
A major limitation to
the expansion of VGT is the lack of
trained and experienced landscapers. This
can be rectified through technical
training workshops for existing and new
landscaping companies. We see a big
increase in demand for VGT, which means
that small farmers will get involved as
suppliers of quality plant material
(training needed here too).
What we are seeing in
south China is an emerging pattern of
increased use of VGT for engineering
purposes. Companies have been established
in Central America, Philippines,
Malaysia, Australia, and South Africa to
produce large quantities of plant
material and to apply the technology to
construction sites. The rate of demand is
likely to go up as more companies are
established and they market the
technology to highway designers and
highway owners. A paper just published on
this homepage shows that in Australia (a
high priced labor market) financial
savings are estimated at over 60% when
VGT is used over conventional methods. In
China the savings are 90%+!!
Other areas of
potential for VGT in China and other
tropical countries is VGT's ability to
stabilize acid sulphate soils in coastal
areas, rehabilitation of mines, and
stabilizing of river banks, dikes and
levees. In China, Bangladesh, and Vietnam
millions of dollars are spent annually on
maintaining the levees of major rivers.
VGT could be used to reduce these costs.
Also published at this
time on the home page are new papers that
confirm VGT application for mine
stabilization, wetlands, infrastructure, and the removal of surplus pesticides from cotton and sugar cane
fields in Australia.
VGT is on the move;
those of you whose main focus is to use
VGT for on farm soil and water
conservation should look at some of these
other applications, because as the demand
for them grow, so will the demand for
vetiver planting stock, most of which
will be produced by small farmers.
Dick Grimshaw
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