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Suppose you were told that a new system of rice
cultivation had been �discovered' that requires half the water needed
for conventional rice cultivation, would increase per acre grain yields
by at least 50%, would substantially reduce or eliminate the need for
chemical fertilisers, would cut seed requirements by up to 95% and yet
make rice cultivation more sustainable and profitable for farmers.
Most people would reject these claims as a figment of
the imagination. Indeed, scepticism was the natural reaction of many
participants at the fourth IWMI-Tata Annual Partners Meet held on
February 24-26, 2005 , in Anand ( Gujarat ) where nine papers on the
system of rice intensification (SRI) were presented.
Let us look at the solid facts before we reject one of
the most remarkable developments in agriculture in recent times. If
found workable, and it seems there is a rapidly building body of
evidence in its favour, the system could have huge implications also for
water resource development in India and other countries as it entails
considerable water saving for water-intensive crops like rice.
What is SRI?
The system of rice
intensification (SRI) is a new and evolving alternative to conventional
methods of rice cultivation. In this method, rice seedlings are
transplanted early (eight to 12 days old compared to 21 days in the
conventional method). They are transplanted in un-puddled condition; the
seedlings are widely spaced (up to 20, 25, 30 or even 50 cm apart). The
fields are alternately kept wet and dry; they are not flooded until the
panicle initiation stage (1-3 cm of water in the field during the
reproductive phase). The field is drained 25 days before harvest and
organic manure is used as much as possible. Mechanical weeding should
start around 10 days after transplantation; at least two weedings are
necessary, more are recommended. It is supposed to provide better
growing conditions in the root zone, save inputs, improve soil health
and optimise water use efficiency.
History
SRI was developed in
Madagascar in the early-1980s by Father Henri de Laulanie, a French
priest. As Shambu Prasad, Prajit K Basu and Andrew Hall note: �SRI has
evolved over two decades, involving 15 years of observation,
experimentation and mastery in Madagascar . It rapidly spread to 21
countries in the next six years.� Uphoff and CIIFAD started popularising
SRI to other parts of the world in 1997, calling it the answer to the
needs of farmers in the 21st century.
Experiments in India
Formal
experimentation in India started in 2002-2003. So far the method has
been taken up in Tamil Nadu, Andhra Pradesh, West Bengal , Jharkhand,
Chhattisgarh and Gujarat .
- Tamil Nadu
During experiments in 2003-2004 at
the Agricultural College and Research Institute and Tamil Nadu
Agricultural University (TNAU), Killkulam, Tamil Nadu, it was found
that, on average, 53% less irrigation water was used in SRI farms. In
these experiments, 21-day-old seedlings were transplanted 15 x 10 cm
apart on the conventional farm. The SRI farm had 14-day-old seedlings
transplanted 20 x 20 cm apart. Water depth on the SRI farm was
maintained at 2.5 cm, with alternate wetting and drying cycles up to
the panicle initiation stage. The farm was flooded to the same depth
thereafter until harvest. On the conventional farm, the depth of the
water was maintained at 5 cm throughout the standing crop. The
experiments showed that SRI recorded higher water productivity of
0.699 kg/m3 compared to conventional farm water productivity of 0.253
kg/m3. The partial factor productivity of nitrogen was 28.3% more
under SRI. The SRI farm recorded a grain yield of 3,892.7 kg/ha, 28%
higher than from the conventional farm.
The results from two on-farm, state government-funded
evaluations by TNAU -- one of which was in the Tamirparani basin in
south Tamil Nadu -- showed that mean grain yields under SRI and
conventional cultivation were 7,227 and 5,637 kg/ha respectively,
showing an overall yield advantage of 1,570 kg/ha (maximum yield
advantage: 4,036 kg/ha) for SRI. Around 31 farmers recorded grain yields
of over 8 t/ha under SRI.
- Andhra Pradesh
On-farm SRI demonstrations
were organised in 22 rural districts during the 2003 kharif season. A
study carried out by the Acharya N G Ranga Agricultural University,
Hyderabad, using 291 respondents including 67 SRI farmers, 71
neighbouring farmers, 77 researchers and 76 extension workers, found
that 95% of seeds on SRI farms were saved, as a seed rate of 5 kg/ha
was sufficient; about 50% of water was saved and an average yield
advantage of 2 t/ha was reported. SRI farmers did have problems using
the rotary weeder, transplanting the young seeds and managing the
water. However, all of them reported that the plants look healthier on
SRI farms.
Through the civil society organisation Timbaktu
Collective, farmers in drought-prone Anantapur district in Andhra
Pradesh have turned crisis into opportunity by employing SRI principles.
- West Bengal
PRADAN has done a study on the
experiences of 110 farmers in Jhalda and Balrampur blocks in West
Bengal 's Purulia district during the 2004 kharif season. The study
found that SRI plots produced an average of 32% higher paddy yields
even with the partial adoption of SRI practices. In the 59 plots in
Balrampur, the average paddy output from SRI farms was 6,282.65 kg/ha
(49.8% higher) compared to 4,194.13 kg/ha in conventional fields.
Average straw output was 5,150.1 kg/ha in SRI fields compared to
3,456.87 kg/ha in conventional fields.
In Jhalda block the
increase was only 11.9% for a number of reasons including drought,
only one weeding and transplantation of older seedlings. Straw output
was 49.13% and 54.34% higher respectively in Balrampur and Jhalda
blocks. Seed requirements for SRI farms were only 2.87 kg/acre
compared to 27.17 kg/acre in the case of conventional farms -- a
saving of Rs 292 per acre. SRI farms also required less labour
compared to conventional farms, resulting in savings of Rs 184 per
acre. The gross return per acre was Rs 3,341 in Balrampur block. The
net return from an SRI farm was 67% higher than a conventional farm.
The results show substantial savings in applied water on SRI farms,
partly due to less percolation and partly due to a reduction in
evaporation from the field.
- Gujarat
During experiments at Anand
Agricultural University , Gujarat , it was found that while the
conventional practice yielded 5,840 kg/ha of grain, the SRI method
yielded 5,813 kg/ha, with 46% less water usage.
- Others
In Pondicherry , SRI trials were done
at the Annapurna farm in Auroville, and later the M S Swaminathan
Research Foundation tried SRI on small plots in the bio-village.
PRADAN also took up SRI work in Jharkhand. Farmers like Kouligi from
Melkote in Karnataka have produced booklets in Kannada on SRI.
Tamil Nadu Agricultural University has recommended SRI
as a technology in Tamil Nadu to increase rice productivity and save
irrigation water. The state department of agriculture held demonstration
trials in all rice-growing areas of the state during the 2004
season.
In Punjab , as reported by Dr Sudhirendar Sharma, the
JDM Foundation in Ladhowal, Ludhiana , is pushing a different version of
low-water-use rice cultivation. According to Dr Sharma, this practice is
the answer to Punjab 's water problems as it can lead to water savings
of up to 60-70% during the paddy-growing season.
Experiments in other countries
SRI
has been tested in 22 countries around the world including predominantly
rice-growing countries like China , Sri Lanka , Cambodia and Indonesia
and it is supposed to have come up with outstanding results.
- Sri Lanka
According to a study by the
International Water Management Institute, SRI farmers reported yield
increases of 44%. Returns on crop budgets were higher, cost of
production per unit of paddy output considerably lower, and average
profits almost double those from conventional farms. It was found that
both rich and poor farmers were equally likely to adopt SRI; once they
adopted the method, however, poor farmers were more likely to continue
with it. Rain-fed farmers saw SRI as an opportunity to minimise losses
associated with weather uncertainties.
Reduction in the use of
chemical fertiliser is an obvious environmental benefit of SRI. The
need for a considerable labour force and the tedious nature of the job
(transplanting, manual weeding) are also seen as problems associated
with conventional rice-growing.
- Nepal
Experiments by 14 village development
committees, in 2004, have shown yields from SRI farms to be more than
double yields from conventional farms.
- Laos
Rice cultivation through SRI has led to
increases in yields from 3.27 t/ha to 5.05 t/ha.
- China
Experiments since 2000 have shown that
rice yields under SRI have risen by 35.6% compared to yields from
conventional rice-growing.
- Philippines
SRI farms achieved rice yields of
7.33 t/ha compared to the most advanced system of conventional
rice-growing where yields were restricted to 3.66 t/ha.
- Cambodia
According to a GTZ-supported study
in 2004, over 400 SRI farmers displayed 41% higher grain yields from
SRI farms.
Implications of SRI for India
Around 5,000 litres of water are required to produce one
kilo of rice. Tamil Nadu has roughly 2 million hectares under rice
cultivation; 70% of the area being irrigated. Rice consumes around 70%
of the water available for agriculture in Tamil Nadu. Over the last four
decades, the area under rice in Tamil Nadu has declined at the rate of
22,900 hectares per year.
Today, India has over 24 million hectares under
irrigated paddy. If SRI were to be applied on all this land we would be
able to increase our irrigated area by at least 50%, using the water now
being used for paddy irrigation. It would also lead to a 50% increase in
rice production. Both these factors would have huge implications for
water resource management in India in the years to come. The question
that immediately springs to mind is: With such far-reaching implications
why is the government not actively pushing the adoption of SRI?
(Himanshu Thakkar is coordinator of the
South Asia Network on Dams, Rivers & People and editor of Dams,
Rivers & People )
InfoChange News & Features, June 2005
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