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| SALINITY IS NO LONGER A THREAT TO THE MAJORITY
OF TSUNAMI-AFFECTED LAND |
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The deterioration of soil fertility due to the salt pollution of agricultural
fields has been a major concern since the 26th of December 2004 when
the tsunami ravaged thousands of kilometers of coast along the shore
of the Indian Ocean penetrating from 0.5 km up to several kms inland.
Agriculture is the second sector affected after fisheries. FAO estimates
that in the countries hardest hit by the disaster (Indonesia, Sri
Lanka, Maldives, India and Thailand) a total of 47,000 ha of agricultural
land has been damaged by huge waves and sea floods leading to massive
crop losses and deterioration of land fertility.
"38,000 ha of the affected areas can be recovered for cultivation
in 2005 while the remaining 9,000 ha should be regarded as lost
to the sea or in such a bad state that alternatives other than agriculture
need to be examined" says Daniel Renault FAO Agriculture Coordinator
for tsunami.
This devastation has adversely affected more than hundreds of thousands
of farmers and families in the region whose livelihoods depend on
agriculture. Furthermore in many countries bordering the Indian
Ocean, home gardens although small in terms of area, are very important
in helping people to sustain their livelihoods, providing additional
nutrients and medicinal plants. In addition to the countless homes
that need rebuilding, more than 40,000 home gardens have been devastated
and salinized by the tsunami and need to be created from scratch.
Tsunami salinity pollution has two origins:
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sea water infiltration during the flood and resulting salt fixation along the top soil profile
and
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saline sea deposits (sand or clay).
The duration of the inundation had a direct impact on the quantity
of infiltrated salt and this depends mainly on the local post-tsunami
drainage capacity.
The fear of a massive decrease in fertility due to soil salinization
has prompted many actors to carry out survey campaigns and careful
monitoring of the local situation. In the days following the disaster
there were wide-spread alarmist reports on the impact of saltwater
on the soil and how reclaiming the land would take many years. Fortunately
this fear is unfounded, or more precisely it is founded on salinity
problems that are very different. It is true that reclaiming soils
in arid countries, which have become salinized due to irrigation
practices or natural accumulation, can take years, but in the case
of sea flash floods it is obvious that the nature, duration and
type of impact are very different.
In early January FAO predicted that in general in the tropical humid
conditions of the Indian Ocean salt-affected fields would return
to their pre-tsunami state in a matter of months. Since then, this
prediction has been largely verified, and recent surveys show that
where fields are well watered by rain or irrigation and well drained,
the situation has returned to normal and farmers have already started
to recultivate their fields.
To help governments and communities tackle the challenges, FAO
has carried out 3 main types of action for salinity issues:
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several survey campaigns of soil and water resource salinity
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provision of hundreds of Ec meters and training to help local
actors deal with the salinity issue
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coordination of efforts for assessment and strategies for recovery.
More than two-thirds of affected arable land is salt cleaned
FAO estimates that for the coming crop season starting in most places
in April and May, more than 2/3 of the affected arable land throughout
the region has been cleaned of salt through precipitation and irrigation.
For the areas yet to be cleaned, the problem is not so much the
severity of the salt pollution but the absence of a means of cleaning
the soil.
"To leach out accumulated salt on the top soil layers you need
to water your field either using natural precipitation or irrigation
water and then you need good drainage, either vertical (on sandy
soil for instance) or surface drainage for paddyfields to evacuate
the saline water " says Daniel Renault, FAO Agriculture Coordinator
for tsunami.
With respect to these means of rehabilitation, i.e. watering and
drainage, the situation varies on the ground. In the Maldives, the
FAO survey shows that the top soil has been largely cleaned from
salinity by recent rains. With the Monsoon in sight, the problems
have receded as far as salt is concerned. On the dry East Coast
of Sri Lanka, heavy precipitations in Trincomalee and Batticaloa
districts immediately after the tsunami, respectively 100 mm and
350 mm, have been a real blessing in terms of land cleaning, whereas
in the nearby district of Mullataivu lack of precipitation and irrigation
facilities associated with very poor drainage will leave depressions
along the coast uncultivated for months to come.
Along the Indian coast of Andra Pradesh and Tamil Nadu, farmers
are waiting for the onset of the monsoon around July, to leach out
their land so that they can begin to cultivate. On the dry East
Coast of Aceh, the recovery from salt contamination is strongly
dependent on irrigation and drainage, while along the severely damaged
West Coast, heavy precipitation has already leached out most of
the contaminated lands.
Sigli
District East Coast Aceh Province - Indonesia
Left picture: (24th February 05) a field still salinized and
water logged 2 months after the disaster, due to lack of irrigation
and proper drainage. The drainage canal shown at the bottom
of the picture is full of sediment and trash.
Right picture: (same day), near-by fields well served by irrigation
and drainage systems on which farmers have started transplanting
immediately, rice is developing well. |
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Special efforts
needed for the areas that are still polluted
FAO recommends that a special effort should be made to provide a
water supply and drainage to areas that have not yet been cleaned.
This of course depends on the local situation, with respect to water
resources and the ability to transport and distribute fresh irrigated
water. Tapping upstream water storage and using natural streams
and pumping facilities for transport and distribution to provide
water to affected fields should be funded through the tsunami recovery
plans.
A Regional
Workshop to consolidate assessments, design land reclamations and
plan agricultural recovery
In line with the coordination intervention FAO - through its Regional
Office for Asia and the Pacific - is convening a regional workshop
to bring together interested parties involved in post-tsunami soil
salinity assessment and rehabilitation work. The workshop will be
held in Bangkok FAO Office the 31st of March and 1st of April, and
will provide participants with an opportunity to share information,
collectively assess initial findings related to rehabilitation needs
and opportunities, share plans and proposals for future rehabilitation
work, and develop mechanisms for collaboration and joint activities.
About 50 experts representing 7 countries are expected at the regional
workshop. It is anticipated that the workshop will lead to a comprehensive
and consolidated assessment of the situation regarding salinity
as well as practical solutions for land reclamation interventions
targeting salt, deposits and erosion. Since salinity is only one
aspect of land rehabilitation and agricultural recovery it is the
intention of the workshop to place the recommendations within a
comprehensive regional framework for agriculture recovery, dealing
with this issue within a much broader perspective.
Salinity is only one of the many constraints affecting the return to cultivation
Although today we can say that soil salinity is declining progressively
and a return to normal conditions for crops can be expected within
a few months for the remaining land that has not yet been cleaned,
a return to cultivation depends on many other factors. Affected
agricultural fields have been damaged by massive erosion, sediment
and trash deposits along with salinity contamination. Leaching out
salts is only one of the issues to be tackled in reclaiming the
land. To revive a healthy agricultural community along the coasts
of the Indian Ocean the perspectives should be further broadened
in order to achieve an integrated approach to repairing the physical
damage, but beyond that to revitalizing the farming systems as well.
"Salt-cleaned lands of the West coast of Aceh may be kept fallow
for different reasons, for example because households have not returned
to their villages/fields; due to shortage of labour to clean and
cultivate the land; and because people have other priorities such
as building/repairing their homes; or are suffering from psychological
trauma; because there is no capital for inputs; and no equipment
and tools" reports Ronald Dijk FAO Agronomist Banda Aceh.
Along with the positive message that initial problems like salinity
are being overcome, the challenges ahead require the continuous
attention of all actors involved.
As rice is the main crop in the region FAO-AGLW proposes below
an example of approach developed for paddyfield but which can be
easily extrapolated to any particular other crop.
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