Salt
threatens Mekong rice By
Marwaan Macan-Markar
BANGKOK - With
Vietnam's fertile Mekong delta threatened by
rising sea levels and salt water ingress, the
country's future as a major rice exporter depends
critically on research underway in the
Philippines.
Scientists at the
International Rice Research Institute (IRRI) are
working with Vietnamese counterparts in the town
of Los Banos, southeast of Manila, to develop a
strain of rice that can withstand submergence for
over two weeks and resistant salinity. A
flood-tolerant variety dubbed "scuba rice", which
has the submergence (SUB 1) rice gene, already
offers half the solution.
"IRRI is
experimenting to find a rice variety to deal with
both problems," says Bjorn Ole Sander, a scientist
at the world's leading non-governmental research
centre on rice. "Even if we
have rice crops that are
tolerant to floods they can die because of
salinity."
Four dams built by China on the
Mekong have already had an impact on the delta's
rice farms. As the usual water flow ebbed, salt
water raced inland and the alluvial soil dumped on
the delta by the river during the annual monsoon
floods also dropped, reducing the natural
fertility.
But the dams have provided
clues to the possible impact of climate change.
Almost one-third of the delta, where nearly half
of Vietnam's rice is grown, could be submerged by
salt water if there is a one-meter rise in the sea
levels, a report by the country's National
Institute for Hydrometeorology and Environmental
Science warned in 2009.
The search for
this grain has its roots in the Indian state of
Orissa, home to a flood-resistant rice variety
that resumes growth after being underwater for
even 14 days - unlike other rice varieties that
die if submerged for just over a week.
"This has been achieved without genetic
manipulation, by breeding the SUB 1 variety,"
Sander said in an interview. "It can be submerged
for 17 days."
But the quest for a
salinity-tolerant variety that could be blended
with "scuba rice" is more daunting. "It will take
at least four years to find a rice variety that
will be tolerant to both - salinity and flooding,"
he said. "That would be the answer to the problems
faced in the Mekong Delta from flooding and
salinity from the rising sea tides."
Salt
water from the South China Sea now spreads 40
kilometers into the delta, unlike the 10 kilometer
inland reach of the sea 30 years ago.
"The
future of the delta is at stake. That is why we
are working with IRRI to develop a rice variety to
deal with floods and salinity," says Nguyen Van
Bo, president of the Vietnam Academy of
Agricultural Science, a government-backed entity
in Hanoi. "Seven percent of the paddy fields in
the delta are affected by rising sea levels."
Already farmers have begun to change
occupations, many going from rice farming to
shrimp farming, he told IPS. "There is a very
noticeable shift from the previous times when
growing rice and shrimp farming were seasonal."
And Vietnam's fate - particularly on the
delta - is going to worsen, warned Asian
agriculture scientists and climate change
specialists at a meeting in Bangkok this month. It
would add to existing woes from erratic weather
patterns that have hit the region's other major
rice producers like Thailand, they added.
The delta accounts for nearly 50% of the
42 million tonnes of unmilled rice produced in
Vietnam, which harvests three annual crops and is
the world's second-largest rice exporter after
Thailand. In 2011, Vietnam exported a record seven
million tonnes of rice, mainly to the Philippines
and other Asian markets.
For over 17
million of Vietnam's 87 million people, who call
the flat, humid delta their home, the network of
waterways has been pivotal to rice production.
These arteries are fed by the Mekong River,
Southeast Asia's largest body of water, which
begins its 4,880-km route in the Tibetan plateau
and flows through southern China, touches Myanmar
and Thailand, and winds its way through Laos,
Cambodia and Vietnam before flowing out into the
South China Sea.
World Bank studies rank
the delta as most threatened by sea level rise
among coastal communities in 87 developing
countries surveyed, if there is a rise in sea
levels.
Warnings in other reports that 21%
of Asia's crops will be affected by the impact of
climate change by 2050 are yet to push government
leaders from the 190 countries who gather at the
annual United Nations climate change summit to
include agriculture in the negotiations.
"Agriculture and food production are
mentioned in the UNFCC [United Nations Framework
Convention on Climate Change] but they have not
been translated into language that will initiate a
specific work program on agriculture in relation
to climate change," says Bruce Campbell at the
Consultative Group on International Agricultural
Research (CGIAR).
"There isn't a common
voice on agriculture at the UNFCCC negotiations,"
said Campbell, a director at CGIAR, which is
sponsored by the Food and Agriculture
Organisation, the International Fund for
Agricultural Development, the United Nations
Development Programme and the World Bank.
"Climate change is impacting farming
systems and it is endangering crops," Campbell
told IPS. "Agriculture systems have to be
transformed to make agriculture climate
resilient."
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