Presented by: Dr Amod L. Thakur Presented at: International Rice Congress. Pre-Congress SRI Day, November 8, 2010

1. Dr. Amod K. Thakur
Directorate of Water Management (ICAR)
Bhubaneswar, Orissa, INDIA
SRI Findings in India
Pre-Congress ‘SRI DAY’
November 8, 2010

2. Objectives
 Varietal performance
 Impact of spacing
 Effect of different N-level
 Effect of water management practices
 Comparative performance

3. Varietal performance
Khandagiri (Short duration)
Surendra (Medium duration)
CRHR-7 (Hybrid)
Lalat (Medium duration - popular variety)
Savitri (Long duration)
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4. • All the varieties performed better under SRI management than
with conventional transplanted management.
• SRI showed 36-49% higher yield than TP
• Short duration variety (Khandagiri): 36%,
• Medium duration and hybrid varieties: 42-45 %,
• Long duration: 49% more yield than TP
SRI: Panicle length, grains per spike, and grain-ripening percent
were the major factors responsible for higher yield than TP
Salient Findings
A. K. Thakur, Sreelata Rath and Ashwani Kumar (2010). Archives of Agronomy and Soil
Science ((Taylor & Francis),
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5. Effect of spacing
Grain Yield (t/ha) under different spacings in SRI and TP
Khandagiri Surendra Savitri
Treatment Yield
(t/ha)
% Change
in yield
Yield
(t/ha)
% Change
in yield
Yield
(t/ha)
% Change
in yield
30 x 30cm 2.97c -1.65 2.94d -33.48 3.86d -19.79
25 x 25cm 3.42b 13.12 4.26bc -3.58 6.31a 31.16
20 x 20cm 4.44a 46.80 6.27a 41.89 6.06a 26.03
15 x 15cm 3.01c -0.39 4.21bc -4.71 4.40c -8.53
10 x 10cm 2.88c -4.80 4.16c -5.84 4.23c -12.10
TP (15x10 cm) 3.02c - 4.42b - 4.81b -
Thakur, A. K.., S. K. Choudhari, R. Singh, and Ashwani Kumar. (2009). The Indian Journal of Agricultural
Sciences 79 (6):443-447.
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6. Optimum spacing:
For short and medium duration varieties with
SRI -- 20 cm x 20 cm
For long duration varieties -- 25 cm x 25 cm
Salient Findings
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At wider spacing (more than 20 cm x 20 cm):
Yield was reduced due to lesser panicle number/m2
At closer spacing (less than 20 cm x 20 cm) :
Yield was reduced due to shorter panicles

7. • Performance of individual hills was significantly
improved with wider spacing compared to closer-spaced
hills.
• In these trials, both SRI and TP gave their highest grain
yield with spacing of 20x20 cm. However, SRI yielded
40% more than the recommended practice. Lowest yield
was recorded at 30x30 cm spacing under both practices,
due to less plant population (11/m2
) despite improved hill
performance.
• Wide spacing beyond optimum plant density does not
give higher grain yield on an area basis, and for
achieving this, a combination of improved hills with
optimum plant population must be worked out for SRI.
A. K. Thakur, S. Rath, S. Roychowdhury & N. Uphoff (2010). Journal of Agronomy & Crop
Science (Blackwell Verlag GmbH), 196:146–159.
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Salient Findings

8. Effect of different N-levels
The effects of different N application rates (0, 60, 90 and 120 kg/ha) were
assessed with the different cultivation systems (SRI and TP).
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Overall, grain yield with SRI practices was 49%
N uptake, N use-efficiency, and partial factor productivity from
applied N were all higher in SRI, which can be attributed to the
greater root development under SRI.
With SRI and TP management, one kg N produced 64 and 43 kg
of rice grain, respectively.
Higher N and chlorophyll content, reflecting delayed
senescence, contributed to an extension of photosynthetic
processes, which translated into increased grain yield under SRI.
A.K. Thakur et al. (2010) Journal of Plant Nutrition and Soil Science (under review)

9. Effect of different water levels
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Highest grain yield at 1 DAD under both cultivation methods. As more
water stress was imposed, the grain yield reduced in both methods, but
the reduction in grain yield was found greater in conventional TP than
SRI. This might be due to deeper and greater root growth under SRI,
which enables the plant to extract water from deeper soil zone.
0
1
2
3
4
5
6
7
CF 1
DAD
3
DAD
5
DAD
7-
DAD
CF 1
DAD
3
DAD
5
DAD
7
DAD
TP SRI
Grainyield(t/ha)
-50
-40
-30
-20
-10
0
10
20
CF
1
DAD
3
DAD
5
DAD
7-
DAD
CF
1
DAD
3
DAD
5
DAD
7
DAD
TP SRI
%changeoverCF

10. Comparison
SRI vs. TP
Thakur, A.K., N. Uphoff, and E. Antony. (2010). Experimental Agriculture
(Cambridge University Press) 46 (1): 77–98.
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11. Root Growth & activity
Tillering under SRI
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Leaf development
Canopy structure & Light
Interception

12. Physiological Observations
• SRI had higher chlorophyll content,
maximum quantum yield of PS II (Fv/Fm)
and actual quantum yield (Φ PS-II)
• Higher photosynthetic rate
• Increasing crop growth rate (CGR)
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13. Yield and yield contributing characters
SRI rice crop had:
• More number of longer panicles,
• More number of grains in spike,
• Higher 1000-grain weight, and
• More grain-ripening percent
These were responsible for higher grain yield.
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14. Rice plant (cv. Ciherang) grown from a single seed
using methods of the System of Rice Intensification
(SRI), in E. Java, Indonesia. Presented by farmers
to N. Uphoff, 6 Oct 2009. The plant produced 223
fertile tillers, which means that it had reached into
the 14th phyllochron of grpwth
Future research needs
 Reason for phenotypic alterations/tillering in SRI plants
(physiological, biochemical, hormonal and genetic changes
in plants responsible for this alteration)
 Study grain-filling and source-sink relationships in rice
grown through SRI methods
 Effects of different components of SRI practice on plant
growth and physiology
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15. Roots are the key to a second green
revolution
(Virginia Gewin (2010) An underground revolution. Nature, 466, 29 July 2010)
 Changes in soil-root environment that occurs in SRI due to
aerobic/semi-aerobic field conditions and the use of a mechanical
weeder needs to be addressed for future research.
 There is also a need to conduct study on nutrient uptake, its
budgeting in SRI, and long-term effects on nutrient status of SRI
field.
 Initial findings have indicated that SRI is drought-tolerant, so
proper experiments are required to assess this observation.
 Root traits that are linked to shoot growth and dry matter
production should be investigated systematically to understand
better how the plasticity of roots could enhance grain yield within
their dynamic soil environment.
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16. Dr. Amod K. Thakur
amod_wtcer@yahoo.com
SRI Research: Still has a long way to go…
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