Seminar by Amod K. Thakur (Borlaug Fellow at Cornell University and Senior Scientist at the Directorate of Water Management (ICAR) in Bhubaneswar, Odisha, India) presented at Cornell University on December 6, 2011. (Co-sponsored by the Dept. of Crop and Soil Sciences, International Programs and SRI-Rice)

1. Dr. Amod K. Thakur
Directorate of Water Management (ICAR), Bhubaneswar
Crop & Soil Sciences Dept. Seminar, Cornell University
December 6, 2011r

2. Facts about Rice…… A Preface
 Rice is main source of directly-consumed
calories for about half of the world’s
population
 Rice provides 23% of all calories
consumed by world’s population
 Rice productivity has stagnated since
the mid-80s
 It is estimated that by the year 2025, the
world’s farmers will need to produce
about 60% more rice than at present to
meet the food demands of the expected
world population at that time (Fageria 2007).

4. Scarcity of water is acute in the world’s ‘rice bowls’
1/3rd of the world’s population
lives with water scarcity & this
proportion will double by 2050

5. Dual challenges
(a) Enhance Food Production
(b) Under Water-Scarce Conditions
Objective-
“More Crop per Drop”

6. SRI
System of Rice Intensification
It involves the use of certain management
practices which together provide better growing
conditions for rice plants, particularly in their root
zones, compared with those for plants grown
under conventional practices
It is a system rather than a technology because it
is not a fixed set of practices. While a number of
specific practices are basically associated with
SRI, these should always be tested and adapted
according to local conditions rather than simply
adopted.

7. Practices
 Transplanting young seedlings
 Minimize time gap between uprooting & transplanting
 Transplant seedlings singly rather than in clumps
 Wider spacing in square pattern
 Keep soil well drained (moist) rather than flooding
 Weeding by mechanical weeder (aerate soil)
 Organic inputs like compost or mulch (optional)

8. Impetus for this research: IRRI Rice Today, July-Sept, 2004
Energy for crop growth results from intercepted sunlight,
and the amount of light intercepted translates directly into
plant growth. High plant density enhances light
interception, growth and yield. SRI suffers from poor light
interception because of low plant densities, acc. to Sinclair.

9. Sheehy et al. 2004 FCR 88:1-8
SRI has no inherent advantage over the conventional system

10. But trials had excessive application of N-fertilizer (180-240
kg N ha-1), causing lodging in some SRI plants (uncommon)
Herbicide was used-, so there was no active soil aeration
as recommended in SRI practice
Comparison was made of yield between 11 SRI plants/m2
(30 x30 cm spacing) with 25 plants/m2 (20 x 20 cm)
If 16 or 25 SRI plants would have been used,
maybe the results would have been different?

11. Research question: Whether SRI practices
have any effect on the grain yield or not?
If so, why?
How do SRI practices affect rice plants’
morphology, their physiology, and what are
their implications for crop performance?

12. Methodology
Location: Deras Research Farm, Orissa, India
DWM (ICAR), India
Season: Dry (January-May) 2006, 2007 & 2008
Soil: Aeric Haplaquepts, sandy clay-loam in texture, pH 5.5.
Design: RCBD - five replicates
Plot sizes: 20 × 10 m2
Variety: Surendra
Crop management systems:
System of Rice Intensification (SRI) compared with
Traditional flooding (TF) using Recommended management
practices (RMP) proposed by Central Rice Research Institute

13. Management
practices SRI TF/ RMP
Seedling age 10-12 21-25
(in days)
Plant spacing 20 x 20 cm 20 x10 cm
DWM (ICAR), India
and density One seedling /hill Three seedlings
/hill
Weed control 3 weedings with 3 manual
cono-weeder @ 10, weedings @ 10,
20 and 30 DAT 20 and 30 DAT
Water AWD after 3 DAD Flooding with 5-6
management during vegetative cm depth of
stage water during the
vegetative stage
Nutrient Organic manure @ 5 t ha-1
management Chemical fertilizers: 80 kg N ha-1,
(not a variable) 40 kg P2O5 ha-1, and 40 kg K2O ha-1

14. Directorate of Water Management, Bhubaneswar, INDIA
Morphological Changes with SRI

15. Root Growth
SRI hills had better root
development (deeper
roots, more dry weight,
root volume and root
RMP SRI length) than rice crop
grown under RMP.
Effects of rice management practices on root depth, root dry weight,
root volume, and root length at early-ripening stage of development
Management Root Root dry Root dry Root Root Root length Root
practice depth weight weight volume volume (cm hill-1) density
(cm) (g hill-1) (g m-2) (ml hill-1) (ml m-2) (cm-2)
SRI 33.5 12.3 306.9 53.6 1340.0 9402.5 2.7
RMP 20.6 5.8 291.8 19.1 955.0 4111.9 1.2
LSD.05 3.5 1.3 NS 4.9 180.1 712.4 0.2

16. Tillering under SRI
The number of tillers per hill
significantly increased (by 2 times, up
to 34 tillers) in SRI compared to RMP.
But the number of tillers per unit area
was found not to differ significantly in
SRI vs. RMP.
Effects of rice management practices on morphological
characteristics at early-ripening stage of development
Management Plant Culm height Ave. tiller Tiller number Ave. tiller
practice height (cm) (cm) number (hill-1) (m-2) perimeter (cm)
SRI 124.2 84.0 18.3 450.1 2.9
RMP 101.4 67.5 8.9 441.2 2.1
LSD.05 8.1 4.3 3.5 NS 0.3
Why?

17. SRI plants were able to complete more
number of phyllochrons (completion of
10 phyllochrons in SRI plants and 8
phyllochrons in RMP) before the onset
of reproductive stage of growth.

18. Phyllochrons
1st 2nd 3rd 4th 5th 6th 7th 8th 9th 10th 11th 12th
New Tillers 1 0 0 1 1 2 3 5 8 12 20 31
Total tillers 1 1 1 2 3 5 8 13 21 33 53 84
Comparison between numbers of phyllochrons completed under SRI and RMP
Prac- 12 DAG 30 DAG 40 DAG 50 DAG 60 DAG 70 DAG
tice
SRI TP < 4th 6th 7– 8th 8-9th 9th 10th
phyllo- phyllo- phyllo- phyllo- phyllo- phyllo-
chron chron chron chron chron chron
RMP In Trans- 6th 7th 8th 8th
mursery planting Phyllo- phyllo- phyllo- phyllo-
shock chron chron chron chron

19.  The number of leaves/hill, leaf area/hill
Leaf development
and area of flag leaves significantly higher
in SRI than RMP.
 The size of individual leaf under SRI is
more than leaves under RMP.
Effects of rice management practices on morphological characteristics
of leaves at flowering stage of development
Management Leaf Leaf Ave. leaf Ave. leaf Ave. flag Ave. flag leaf
practice number number length (cm) width (cm) leaf length width (cm)
(hill-1) (m-2) (cm)
SRI 79.8 1997.6 65.25 1.82 39.45 2.10
RMP 35.6 1766.5 48.14 1.34 30.27 1.66
LSD.05 15.8 229.4 6.09 0.21 4.49 0.31

20. Canopy structure SRI plants had higher LAI than RMP.
Greater SLW of leaves under SRI
shows greater thickness of leaf.
SRI: Open-type canopy structure
RMP: Closed-canopy structure
Effects of rice management practices on LAI, SLW and
canopy angle at flowering stage of development
Manage- LAI SLW Canopy
ment (mg cm-2) angle
practice ( )
SRI 3.95 5.50 33.1
RMP 2.60 4.89 17.8
LSD.05 0.28 0.34 3.6

21. Comparison of leaf inclination at early-ripening
stage under SRI and RMP
Management 1st leaf 2nd leaf 3rd leaf 4th leaf 5th leaf
practice (flag
leaf)a
SRI 7.5 4.9 7.5 10.7 15.9
RMP 9.2 7.3 9.9 13.7 19.9
LSD.05 0.8 0.6 0.8 1.3 1.8
a Angle between flag leaf and panicle axis

22. Directorate of Water Management, Bhubaneswar, INDIA
Physiological Changes with SRI

23. Effects of rice management practices on xylem exudation
rates at early-ripening stage of development
Manage- Amount of Amount of Rate per hill Rate per area
ment exudates per hill exudates per (g hill-1 h-1) (g m-2 h-1)
practice (g hill-1) area (g m-2)
SRI 7.61 190.25 0.32 7.93
RMP 2.46 122.95 0.10 5.12
LSD.05 1.45 39.72 0.06 1.66

24. 60
CGR (g m-2 day-1)
50
40
30
20
10
0
30-40 40-50 50-60 60-70
Period (Days after germination)
Crop Growth Rate
The increase in CGR in SRI crops was
mainly due to maintenance of leaf area
(lower leaf senescence). Lower rate of leaf
senescence might be due to larger amounts
of cytokinins (xylem exudates) transported
from roots.

25. Light Interception SRI plants: intercept more light
without shading
RMP plants: in closed canopy,
lower leaves experiences more
shading
100
At PI stage: light
Light Interception
80
interception reached 89%
60
in SRI canopies, while in
(%)
40
RMP canopies this was
20 only 78% -- giving SRI
0 plants a 15% advantage
12 25 30 40 50 60 70
Days after seed germination

26. Changes in leaf chlorophyll content at
different growth stages in SRI and RMP
%
4 Flag SRI decrease
3.5 Flag TF from
Chlorophyll content (mg g-1
3 Fourth SRI FL-LR
Fourth TF
2.5 SRI-Flag 35.93
leaf
2
FW)
1.5 RMP- Flag 48.94
leaf
1
0.5
0 SRI-4th leaf 39.44
FL MR LR RMP- 4th 56.14
Stages leaf
FL: Flowering stage; MR: Middle-ripening stage; LR: Late-ripening stage

27. Changes in chlorophyll fluorescence (Fv/Fm)
at different growth stages in SRI and RMP
0.9 Flag SRI
Flag TF % decrease
0.8 from
Fourth SRI
Fourth TF FL-LR
0.7 SRI-Flag leaf 22.77
RMP- Flag leaf 31.81
Fv/Fm
0.6
0.5
SRI-4th leaf 27.55
0.4 RMP- 4th leaf 31.88
0.3
FL MR LR
Stages
FL: Flowering stage; MR: Middle-ripening stage; LR: Late-ripening stage

28. Changes in chlorophyll fluorescence (Φ PS II)
at different growth stages in SRI and RMP
0.650 Flag SRI
Flag TF
0.600 Fourth SRI %
Fourth TF
0.550
decrease
from FL-
0.500
LR
0.450
SRI-Flag leaf
Ф PS II
9.93
0.400
RMP- Flag leaf 21.62
0.350
0.300
0.250 SRI-4th leaf 15.31
0.200 RMP- 4th leaf 24.27
FL MR LR
Stages
FL: Flowering stage; MR: Middle-ripening stage; LR: Late-ripening stage

29. Changes in photosynthesis rate at different
growth stages in SRI and RMP
30 Flag SRI
Flag TF % decrease
25 Fourth SRI from
20
FL-LR
Pn (µ mol m-2 s-1)
SRI-Flag leaf 43.20
15
10
RMP- Flag leaf 51.09
5
0 SRI-4th leaf 52.98
FL MR LR
Stages RMP- 4th leaf 59.02
FL: Flowering stage; MR: Middle-ripening stage; LR: Late-ripening stage

30. Directorate of Water Management, Bhubaneswar, INDIA
Performance with SRI

31. Yield & yield-contributing SRI: Longer panicles, more
Characteristics number of grains in spike (40%),
higher 1000-grain weight, and
more grain-ripening percent than
the RMP crop, responsible for
higher grain yield (42%)
Parameters SRI RMP LSD0.50
Panicles / m2 439.5 421.2 ns
Ave. panicle length (cm) 22.5 18.7 2.3
Spikelets / panicle 151.6 107.9 12.9
Filled spikelets (%) 89.6 79.3 5.1
1000-grain weight (g) 24.7 24.0 0.2
Grain yield (t/ha) 6.41 4.50 0.23
Harvest Index (HI) 0.47 0.32 0.04

32. Distribution of panicles according to their
length under SRI and RMP
350
Panicle number/m2
300
SRI TP
250
200
150
100
50
0
Short Medium Long Extra long
Category of panicles
Short: >10 cm - 17 cm
Medium: 17.1 cm - 20 cm
Long: 20.1 cm - 24 cm
Extra-long: 24.1 cm - <26 cm

33. Tiller number
Panicle number
Roots growth and activity
Panicle length
Canopy development
Higher Yield
Light utilization
Grains per spike
in SRI
Grain filling

34. HIGHER GRAIN YIELD
Increased effective tillers Enhanced panicle length,
More grain number & grain filling
Open hill structure Greater light interception
More erect leaves
Enhanced photosynthesis rate
Higher LAI
Higher leaf N-content,
Increased leaf More chlorophyll content
number & leaf size More Rubisco
Delayed senescence More photosynthates
to the roots
Higher nutrient uptake
CK
Higher microbial activity
Greater root growth and activity
A schematic model showing factors that may be responsible for higher grain yield of
rice plant grown under SRI management practices. (CK: Cytokinins; LAI: Leaf area
index; Rubisco: Ribulose-1,5-bisphosphate carboxylase/ oxygenase)

35. Salient findings
Significant changes were observed in the
morphological and physiological characteristics
of SRI plants:
• Greater root growth & activity
• Improved shoot growth
• Greater LAI
• Favourable canopy structure
• Higher levels of leaf chlorophyll
• Increasing fluorescence efficiency
• Photosynthetic rate
• Delayed senescence

36. These factors contributed to :
 Larger panicles (more spikelets per panicle)
 Better grain setting (higher % of filled grains)
 Heavier individual grains (higher 1000- grain
weight), and consequently
 Higher grain yield

37. Take-home points
Improvement in grain yield under SRI is
attributable to improved morphology and
physiological features of the rice plant both
below and above ground (better and positive
root-shoot interaction).
SRI methods narrow the gap between genetic
potential and in-field yield achievements
through management practices.

39. Factors for giving super-high yield in
super high-yielding rice
Akenohoshi (a slowly-senescing and high-
yielding cultivar) produces high dry matter
production as a result of maintaining a high
rate of photosynthesis, which is a
consequence of the delayed senescence of
its leaves, resulting from transport of large
amounts of cytokinins from the roots to the
shoots (Jiang et al. 1988, Soejima et al. 1995).

40. Variety: Xieyou 9308
Maintain higher root activity and cytokinin
content
Delayed senescence and highly efficient
photosynthetic performance during grain-
filling stage
(Shu-Qing et al. 2004 JACS 190, 73-80)
SRI plants had similar characteristics as that of
the super high-yielding varieties- Xieyou 9308 and
Akenohoshi – achieved through changes in
management practices

41. SRI: Experience

42.  Varietal performance
 Impact of spacing
Objectives Effect of water management practices
 Effect of different N-level
 Evaluation of SRI components
 Performance under Integrated SRI

43. Varietal performance

44. Khandagiri: Short-duration
Surendra: Medium-duration
CRHR-7: Hybrid
Lalat: Medium-duration
(popular variety)
Savitri: Long-duration

45. • All the varieties performed better under SRI than
conventional transplanted rice.
• 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: More panicle length, grains per spike and grain
ripening percent are the major factors responsible
for higher yield than TP.

47. Effect of spacing

48. Experiment 1
Grain yield (t/ha) under different spacing in SRI and TP
Khandagiri Surendra Savitri
Treatment Yield % Yield % Change Yield %
(t/ha) Change (t/ha) in yield (t/ha) Change
in yield in yield
M1: 2.97c -1.65 2.94d -33.48 3.86d -19.79
30 x 30cm
M2: 3.42b 13.12 4.26bc -3.58 6.31a 31.16
25 x 25cm
M3: 4.44a 46.80 6.27a 41.89 6.06a 26.03
20 x 20cm
M4: 3.01c -0.39 4.21bc -4.71 4.40c -8.53
15 x 15cm
M5: 2.88c -4.80 4.16c -5.84 4.23c -12.10
10 x 10cm
M6: TP 3.02c - 4.42b - 4.81b -
(15x10 cm)
Thakur, A. K.., S. K. Choudhari, R. Singh, and Ashwani Kumar. (2009). The Indian Journal of
Agricultural Sciences 79 (6):443-447.

49. a.Short-duration variety (Khandagiri)
450 30
400
25
Panicle number/m2
Panicle length (cm)
350
300 20
250
15
200
150 10
100
5
50
0 0
M1 M2 M3 M4 M5 M6
Treatment
Panicle number /m2
Panicle length (cm)

50. b. Medium-duration variety
450
(Surendra) 30
400
25
Panicle number/m2
Panicle length (cm)
350
300 20
250
15
200
150 10
100
5
50
0 0
M1 M2 M3 M4 M5 M6
Treatment
Panicle number /m2
Panicle length (cm)

51. c. Long-duration variety (Savitri)
450 30
400
25
Panicle number/m2
Panicle length (cm)
350
300 20
250
15
200
150 10
100
5
50
0 0
M1 M2 M3 M4 M5 M6
Treatment Panicle number /m2
Panicle length (cm)

52. Salient Findings
Optimum spacing:
For short and medium-duration varieties for SRI, this
was 20 cm x 20 cm (under the trial conditions)
For long-duration varieties, it was 25 cm x 25 cm
At wider spacing (more than optimum): Yield was
reduced due to lesser panicle number/m2
At closer spacing (less than optimum) : Yield was
reduced due to shorter panicles

54. Experiment 2
Variety: Surendra (medium-duration)
Method: SRI and RMP
Spacing: 5 spacings (30x30 cm; 25x25 cm;
20x20 cm; 15x15 cm; 10x10 cm)

55. Grain Yield
Plant spacing Grain yield (g m-2)
SRI RMP Mean
30x30 cm 295.4 247.0 271.2
25x25 cm 426.3 397.9 412.1
20x20 cm 627.7 448.1 537.9
15x15 cm 421.8 403.4 412.6
10x10 cm 388.2 342.9 365.6
Mean 431.9 367.9
Practice Spacing PxS
LSD0.05 18.5 19.4 27.5
Grain yield was significantly larger in the SRI than in the RMP
when plants with the same planting spacing were compared.
Largest yield at 20x20 cm spacing; lowest at 30x30 cm.

56. LAI & Light Interceptio
Flowering stage
5.00 100
4.50 90
Light interception (% )
4.00 80
3.50 70
3.00 60
LAI
2.50 50
2.00 40
1.50 30
1.00 20
0.50 10
0.00 0
30x30 cm 25x25 cm 20x20 cm 15x15 cm 10x10 cm
Plant spacing

57. Salient Findings
At wider or closer than optimum, grain yield decreased in both
practices. At wide spacing, yield reduction was due to the less
number of hills/m2, and at closed spacing, yield reduction was due
to shorter panicles with lower grain number.
Chlorophyll content and photosynthetic rate of both flag leaf and
4th leaf was significantly higher in plants at wider spacing than in
the closer-spaced plants. At all the spacings, these physiological
parameters were greater in SRI compared to RMP.
Performance of individual hills was significantly improved with
wider spacing compared to closer-spaced hills.
Both SRI and TP gave their highest grain yield with spacing of
20x20 cm in these trials. 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),
in spite of the improved hill performance.

58. Wide spacing beyond optimum plant density
does not give higher grain yield on an area basis.
For achieving this under SRI, a combination of
improved hills with optimum plant population
must be worked out under the specific soil and
climatic conditions with the particular variety.
In some locations, e.g., East Java, Indonesia, the
optimum spacing has proved to be 30x30 cm

60. Effect of different N-level

61. Methods: SRI and conventional transplanting
flooded practice of rice cultivation method (TF)
N-doses: Four rates of N (0, 60, 90, and 120 kg
N per ha)

62. Grain yield & HI
Straw dry weight Grain yield Harvest Index
N rate (t ha-1) (t ha-1)
SRI TF Mean SRI TF Mea SRI TF Mean
n
N0 2.76 2.29 2.52 2.32 1.36 1.84 0.46 0.37 0.41
N60 5.77 4.55 5.16 4.27 2.75 3.51 0.43 0.38 0.40
N90 6.49 7.64 7.06 6.31 4.20 5.25 0.49 0.35 0.42
N120 7.55 7.25 7.40 6.07 4.37 5.22 0.45 0.38 0.41
Mean 5.64 5.43 4.74 3.17 0.46 0.37
LSD0.05
Cultivation ns 0.14 0.02
practice (CP)
Nitrogen level 0.31 0.14 ns
(N)
CP x N 0.44 0.20 0.03
SRI increased yield by 49% compared to TF
Yield enhancement was due to improvement in HI

63. N-uptake & use-efficien
N rate N uptake (kg ha-1) ANUE (kg kg-1) PFP (kg kg-1)
SRI TF Mean SRI TF Mean SRI TF Mean
N0 27.38 24.17 25.78 - - - - - -
N60 41.16 38.58 39.87 32.59 23.25 27.92 71.21 45.87 58.54
N90 58.32 54.30 56.31 44.32 31.55 37.94 70.07 46.62 58.35
N120 82.47 76.75 79.61 31.30 25.13 28.22 50.61 36.44 43.53
Mean 52.33 48.45 36.07 26.64 63.96 42.98
LSD0.05
Cultivation 2.49 3.10 1.89
practice (CP)
Nitrogen level 1.89 2.00 1.65
(N)
CP x N ns 2.84 2.34

64. Salient Findings
Overall, grain yield increase with SRI practices was 49%
N uptake, N use-efficiency, and partial factor productivity (PFP)
from applied N was higher in SRI, which was attributable to the
greater root development under SRI
With SRI and TP management, one kg of added N produced 64
and 43 kg of grain, respectively
Higher nitrogen 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. (2011) Plant and Soil (under review)

65. Effect of different water level

66. 7
6
Grain yield (t/ha)
5
4
3
2
1
0
CF 1 3 5 7- CF 1 3 5 7
DAD DAD DAD DAD DAD DAD DAD DAD
TP SRI
Highest grain yield at 1 DAD under both cultivation methods

67. 20
10
% change over CF
0 CF
DAD
DAD
DAD
DAD
CF
DAD
DAD
DAD
DAD
7-
1
3
5
1
3
5
7
-10
TP SRI
-20
-30
-40
-50
As more water stress was imposed, grain yield reduced in both
methods, but the reduction in grain yield was found to be 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 zones

68. SRI components and their
synergies

69. Grain Yield
Treatments Grain yield (g/m2)
AWD CF
25 × 25 cm 20 ×10 cm 25 × 25 cm 20 ×10 cm
CW MW CW MW CW MW CW MW
1 Organic 522.3 501.7 468.3 458.4 468.2 416.3 417.9 427.0
14 seedling Org + 607.4 587.3 576.2 517.8 523.6 498.4 469.2 547.8
days Inorg
3 seed- Organic 428.7 416.3 478.7 476.8 398.7 387.6 447.7 397.6
lings Org + 475.4 412.7 376.9 397.4 368.9 447.1 311.9 377.6
Inorg
1 Organic 327.8 311.6 311.9 301.5 340.8 361.0 264.5 346.5
24 seedling Org + 359.7 427.2 368.9 407.3 284.2 335.0 326.9 278.4
days Inorg
3 seed- Organic 311.4 288.2 343.3 380.0 318.2 296.0 368.1 316.8
lings Org + 359.0 317.8 412.0 434.2 422.3 378.4 307.4 258.4
Inorg
AWD: Alternate wetting and drying; CF: continuous flooding;
CW: weeding by cono-weeder; MW: manual weeding by hand

70. In summary, the effect of various SRI components on grain yield area as follows-
Grain yield (g/m2) Change in SRI
SRI Conventional (in (in %)
practices practices g/m2)
No of seedlings 416.28 378.48 37.80 9.99
Seedling age 456.49 338.27 118.22 34.95
Fertilization 383.12 411.65 -28.53 -6.93
Spacing 403.10 391.67 11.43 2.92
Weeding method 397.70 397.07 0.63 0.16
Water management 417.63 377.14 40.49 10.74
Mean 412.39 382.38 30.01 7.85

71. Salient Findings
Significantly higher number of tillers and panicles per
hill was recorded due to SRI practices like wider
spacing, younger seedling, intermittent irrigation, and
mechanical weeding
Grain yield was found significantly higher due to SRI
practices like- single seedling, wider spacing, younger
seedling, intermittent irrigation. and mechanical weeding
Plots that received only organic (FYM) fertilization gave
lower yield than mixed inorganic-organic fertilized plots
Need more research

72. Performance evaluation of Integrated
SRI

73. Treatments
T1 Rice grown following conventional
methods; all rainwater was harvested in the
field with no supplementary irrigation
T2 Rice grown following SRI methods; all
rainwater was harvested in the field with no
supplementary irrigation
T3 Rice grown following SRI methods; no
stagnant was kept in the field (excess water
was drained) and 3 supplementary irrigations
were provided during flowering and grain
filling stages
T4 Rice grown following SRI methods; no
stagnant was kept in the field (excess water
was stored for fish culture in the refuge) and 3
supplementary irrigations were provided
during flowering and grain filling stages
through stored water

74. Treat Grain Water Total Income Income Net Profit Net water Gross water
- yield required expenditure from rice from fish (Rs./ha) Productivity Productivity
ment (t/ha) (m3/ha) (Rs./ha) (Rs./ha) (Rs./ha) (Rs./m3 (Rs./m3
s water) water)
T1 2.36 6509 16900 18880 - 1980 0.30 2.90
T2 4.21 6509 16500 33653 - 17153 2.64 5.17
T3 5.96 10009 17500 47653 - 30153 3.01 4.76
T4 6.22 6509 21500 36510 21360 36370 5.51 8.81

75. Estimated average productivity of inputs on SRI
and RMP
Units SRI RMP
Seed Kg per kg seed 797.13 59.83
Fertilizer Kg per kg fertilizer 12.99 9.14
Labour Kg per man-days 35 23
Land Kg per ha land 6377 4487
Water Liter water per kg 1571 2801
SRI methods enhance paddy yields, increase returns,
and save labour and water. They enhance productivity
with respect to all of the key inputs in terms of paddy
output per unit of seed, fertilizer, labour-days, and water

76. Directorate of Water Management, Bhubaneswar
Sri Lanka
Cambodia
‘Swarna’ in AP:
Ave. yield: 6.5
t/ha
SRI yield: 10.2
t/ha

77. SRI Crop at IARI, 2004
Directorate of Water Management, Bhubaneswar
Madagascar SRI field, 2003
Cuba – Two plants of the same age
(52 DAP) and same variety (VN 2084)

78. Directorate of Water Management, Bhubaneswar
Eastern Indonesia - Nippon Koei
Irrigation Project, 2004
Morang District, Nepal - 2005

79. Directorate of Water Management, Bhubaneswar
Punjab
WTCER, Bhubaneswar - 2007

80. Some of the reported effects of different SRI practices
SRI Practices Effects
Transplanting Greater root growth, more cytokinin flux towards
single seedlings shoots, delayed senescence, higher
with wide spacing photosynthesis (San-oh et al., 2004; 2006)
Transplanting Early tillering, greater nutrient uptake (Mishra and
young seedlings, Salokhe, 2008), greater yield (Pasuquin et al., 2008;
quickly, carefully Menete et al. 2008)
and at shallow
depth
Intermittent Water saving (Bouman et al., 2007; Satyanarayana
irrigation /AWD et al., 2007; Zhao et al., 2009)
Greater root growth (Satyanarayana et al., 2007)
Improves ROA, cytokinin concentration in roots
and shoots, leaf PS rate, and activities of key
enzymes involved in sucrose-to-starch conversion
in grains (Zhang et al., 2009)

81. Some of the reported effects of different SRI practices
SRI Practices Effects
Use of organic Root growth and nutrient uptake enhanced (Yang et
manure al., 2004)
Microbial biomass and activity increased (Gayatri,
2002)
Compost application (@12 t/ha) increased the rice
grain yield by 12-13.5% (Menete et al., 2008)
Weeds controlling Aerobic soil condition improves root growth
with mechanical (Satyanarayana et al., 2007)
weeder

82. Future Research Needs
Directorate of Water Management, Bhubaneswar
Reason for the phenotypic alterations/tillering in SRI
plants: what are the physiological, biochemical,
hormonal, and genetic changes in plants responsible for
these alterations
Study grain-filling, source-sink relationships, and grain
quality in rice grown through SRI methods
There is considerable evidence for stimulating effects
of soil aeration on N mineralization, like intermittent
drainage favouring the accumulation of nitrate with
subsequent denitrification. In view of current trends to
minimize water use in rice cultivation, it is a challenging
research issue to re-examine the quantity of N losses via
nitrification-denitrification (nutrient budgeting).

83. Effects of fluctuating aerobic and anaerobic
Directorate of Water Management, Bhubaneswar
conditions on microbial populations, their activity, C and
N dynamics, GHG emissions, and crop N supply.
How do SRI practices affect diversity and functioning
of soil microbial populations, what is effect of these
populations in turn on crop performance, with
consideration of the role of micronutrients?
Roots are the key to a second green
revolution
Virginia Gewin (2010) ‘An underground revolution.’
Nature, 466, 29 July 2010
Need for breeding crop plants with deeper and bushier root ecosystems
could simultaneously improve both the soil structure and its steady-state
carbon, water, and nutrient retention, as well as sustainable plant yields.
(Douglas Kell (2011) Annals of Botany)

84. Rice plant (cv. Ciherang) grown using
System of Rice Intensification (SRI)
methods in Indonesia, producing 223 tillers
from a single seed, which means that it had
reached into the 14th phyllochron of growth

85. SRI: Still has a long way to go…

86. Acknowledgement
• USDA, CSS, Cornell University and ICAR
• Norman Uphoff, Janice Thies, Francine,
Harold, John Duxbury, KV Raman, Erika, Lucy
• My friends at Cornell: Jin, Charles, Pulver, Lu,
Shafiq, Aisha, Nicole, Rao, Vinod, Dr. Mehta
All of You

87. Thanks
Rice field art in Japan, just using plants

88. Discussion?