The document discusses the System of Rice Intensification (SRI) practices for growing rice. SRI focuses on improving soil conditions and plant growth through young seedlings, wide spacing, soil aeration, and organic matter addition. Key practices include transplanting young seedlings 8-12 days old in a square pattern with wide spacing, mechanical weeding, and water management to keep soil aerobic. SRI can result in higher yields with fewer inputs through increased root and soil organism growth. Farmers are encouraged to experiment and innovate with SRI methods to suit their local conditions.

1. The System of Rice
Intensification (SRI):
Practices
Cornell International Institute for Food,
Agriculture and Development (CIIFAD)
and Association Tefy Saina, Madagascar

2. I. SRI Around the World:
Africa, Latin America, Asia

3. An SRI field at Ambatovy, Madagascar, 2003

4. Cuba -- CPA Camilo Cienfuegos cooperative -- 14 t/ha

5. An SRI field in Sri Lanka, 2002 – 13 t/ha yield

6. SRI field in Yunnan, China, hybrid variety, 2004 – 18 t/ha

7. I. BASIC IDEAS FOR SRI

8. SRI is a set of principles and methods
that help farmers get more productive
rice plants from ANY VARIETY of rice
SRI methods accomplish this improvement
by making changes in the management
of plants, soil, water, and nutrients to
(a) induce greater ROOT GROWTH, and
(b) nurture more abundant and diverse
populations of SOIL ORGANISMS

9. SRI Practices Should Always
be Varied to Suit Conditions
The basic practices -- starting points -- are:
• Transplant young seedlings ( < 15 days ) –
although direct-seeding is becoming an option
• Wide spacing – single plants, in square pattern
• Soil aeration – thru water management and
weeding, so aerobic conditions prevail in soil
• Organic matter added to enhance the soil –
fertilizer is not needed but it does raise SRI yield
Weed control with ‘rotating hoe’ is recommended
Farmer innovation is an important part of SRI

10. LESS CAN PRODUCE MORE
by utilizing biological potentials & processes
• Smaller, younger seedlings become
larger, more productive mature plants
• Fewer plants per hill and per m2 will give
higher yield if used with other SRI practices
• Half as much water produces more rice
because aerobic soil conditions are better
• Fewer or even no purchased inputs can
make greater output possible, because soil
organisms increase and are more active
• Living soil is the key to SRI performance

11. III. SRI PRACTICES

12. Seed Preparation
• Seed selection
• Seed amounts
• Nursery size as ratio to field
• Seed preparation (soaking, warming)
• Etc.

13. If Transplanting --
Start with Young Seedlings
• SRI can be practiced with direct seeding
• Many farmers are experimenting with this,
and have good results -- saving labor
• But many farmers prefer transplanting
because it assures good establishment
• The critical thing is to PROTECT AND
TAKE GOOD CARE OF THE ROOTS
• These are the key to SRI success

14. SRI Nurseries are Like a Garden
• No continuous flooding of the seedlings
• Soil should be light and easy to work
with – so seedlings can be separated
when transplanting
• Mixture of organic matter with the soil
Conventional nursery
in Tamil Nadu, India

15. SRI nursery
in Tamil Nadu, India

16. Small nursery in Sri Lanka
Note that this is enough
for much larger field
Note also elevation of soil
to keep roots from being
suffocated by water
Note rake-marker on left, used
to mark square pattern on field

17. Transplanting is Most
Important Operation for SRI
• Young seedlings, 8-12 days old (< 15 d),
should be removed carefully from the
nursery, keeping the seed sack attached
to the roots
• Transplanting should be done within 15-
30 minutes after removal from nursery,
keeping mud attached to root so that it
does not dry out

18. 10-day-old seedlings being taken
from nursery, very carefully

19. Pulling out of seedlings in Tamil Nadu
Conventional SRI

20. Transport of seedlings
Conventional SRI

21. Planting in a Square Pattern
with Wide Spacing is Important
• Square spacing will permit efficient
weeding with rotary hoe
• Recommend to start with 25x25 cm
spacing; but 30x30 or 35x35 better?
• If soil is very good, or as it improves
with SRI practice, spacing can be
greater, eventually to 40x40 or even
50x50 cm

22. Different Methods for Spacing
• SRI was developed using strings
across the field tied to sticks; this
gives good precision but takes time
• Most popular method now is use of a
simple wooden rake with desired
spacing, pulled in two directions
• Most recent innovation is a roller-
marker that is cheap and saves time

23. Conventional planting

24. SRI planting in Tamil Nadu

25. Field marking with rake

26. Separating seedlings
for transplanting
Yellow color is from sunlight

27. Planting seedlings shallow,only 1-2 cm deep,
keeping seedling roots as horizontal as possible

28. Roller-marker devised by Lakshmana Reddy, East Godavari,
AP, India, to mark a square pattern on field and save time
in transplanting operations; his yield in 2003-04 season
was 16.2 t/ha paddy rice (dry weight)

29. Transplanted fields in Tamil Nadu, India
Conventional
SRI

30. Careful Transplanting Is Key
• Plants should be set into muddy soil
no deeper than 1-2 cm
• Seedlings should not be pushed down
into the soil
– This will turn the root tip upward and slow
the plant’s resumption of growth
– The seedling shape should be more like
an L than like a J
• Direct seeding is being experimented
with by some farmers to save labor

31. Seeder developed by Luis Romero, Cuba, for planting
pregerminated seed, sowing 40x40 cm (too wide)

32. Variations in Plant Establishment
• Broadcast germinated seed or young
seedlings – seeding rate of 25 kg/ha –
developed by A. Subasinghe, Sri Lanka
• After about 10 days, use rotating-hoe
weeder to ‘weed’ the field as normal
recommended for SRI
• This THINS the crop, leaving only a few
plants (1-2) at each intersection of rows
• This method saves labor for making a
nursery and for transplanting seedlings

33. Variations in Plant Establishment
• In China, a ‘triangular’ method for trans-
planting was developed by Liu Zhibin,
farm manager in Meishan, Sichuan
• This increases plant population by
having 3 plants per hill with
– wider spacing between hills and
– fewer hills
• The best spacing for particular soil and
climate conditions and particular variety
should be determined by experimentation
• Spacing between plants is 7-10 cm

34. Square planting with single seedling
40cm
Original 40
cm
SRI

35. Oblong planting with triangle pattern
45cm 7cm
Improved 40
cm
SRI

36. Comparison between Triangle SRI and
Standard SRI (SAAS, 2002)
Comparison with CK
Transplanting Yield
Pattern (T/ha)
+ T/ha +%
Traditional (CK) 8.65 -- --
Standard SRI 10.42 1.77 20.4
Oblong + triangle
SRI
13.39 4.74 54.8

37. Innovation Is Part of SRI
• Kadiramangalam method developed by
Gopal Swaminathan, Tamil Nadu, India:
– where intense summer heat is too much for
tiny young seedlings, he transplants them in
hills of 3 at 15 days at 30x30 cm spacing,
and re-transplants at 30 days at 30x30 cm
– this method takes more labor, but it gives
100% survival rate and assured yield of 8 t/ha
• Farmers are encouraged to experiment
with variations in timing, spacing, etc. to
find best practices for their conditions

38. Innovation Is Part of SRI
• Gopal Swaminathan, Tamil Nadu, India,
has also developed a 4-row weeder that
works with his soils and saves time
• Ariyaratna Subasinghe, Sri Lanka, has
built a motorized weeder that greatly
reduces his labor time for weeding, so he
can handle 2 ha SRI rice field by himself
• Farmers are encouraged and expected to
make further improvements in SRI
methods as they gain experience with it

39. 4-row weeder designed
by Gopal Swaminathan,
Tamil Nadu, India

40. Motorized
weeder
developed by
S. Ariyaratna,
Sri Lanka

41. Weeding Is Important for Yield
• This activity does more than remove weeds
• Mechanical weeding with rotating hoe or
cono-weeder
– Returns weeds (organic matter) to the soil
– Aerates the soil, supporting soil organisms
• We have some evidence that additional
weedings will add to yield, without fertilizer
• Farmers can experiment for themselves
weeding different parts of field 2x, 3x or 4x

42. Effects of Weeding on Yield
Results for 76 farmers around
Ambatovaky, Madagascar, 1997-98
No. of No. of Average Ave.
weedings farmers yield (t/ha) increase
None* 2 5.9 --
One/two 35 7.5 1.6
Three 24 9.1 1.6
Four 15 11.7 2.6
*Hand-weeding only; labor cost for weeding was about $25/ha

43. Conventional weeding

44. Rotary weeder
 Handle

46. Using rotary weeder

47. Cono-weeder

48. Using cono weeder

49. Good Water Management Is
Required for Best Results
• During weeding, fields are flooded --
but otherwise, fields are not kept flooded
• The ideal is to provide the plant with a
‘minimum of water,’ i.e., enough water
to meet plants’ needs, but not so much
that:
– Roots’ access to oxygen is interrupted,
since they air to keep from degenerating, or
– Soil organisms which need oxygen are lost
and only anaerobic organisms survive

50. Water Management Methods Can Vary
• Original recommendation was to add
small amounts of water on daily basis,
preferably in afternoon or evening,
enough to wet the soil, and to drain off
any remaining excess the next morning
• This would be done during the period of
vegetative growth, with several periods
of no watering for 3-6 days, to dry soil
• After panicle initiation, only 1-2 cm of
water is kept on the field until 10 days
before harvest -- when field is drained

51. Water Management Methods Can Vary
• This may be more water than needed
• Many farmers practice alternate wetting
and drying (AWD), flooding field for 3-6
days, then draining it to be dry 3-6 days
• This reduces labor requirements; yield
may be lower, but labor cost is less
• Best amounts and timing of water will
depend on soil and other factors
• Farmers are encouraged to experiment to
determine best water practices for field

52. Conventional irrigation

53. Water-saving irrigation

54. Case Study from China: Evaluation of SRI in
Xinsheng Village, Dongxi Township, Jianyang
County, Sichuan Province, August 2004, done
for China Agricultural University (Li et al., 2004)
• 2003 – 7 farmers used SRI
• 2004 – 398 farmers used SRI (65%)
• 2003 – SRI plot size average 0.07 mu
• 2004 – SRI plot size average 0.99 mu
• 86.6% of SRI farmers (65/75) said they
would expand their SRI area next year
or keep their whole rice area under SRI
• Why the rapid acceptance of SRI?

55. 2003 WAS A DROUGHT YEAR
RICE YIELD (t/ha)
2002 2003 2004
Standard 6.02 4.47 5.64
Methods
SRI Methods -- 6.60 7.61
(SRI Increase) (46.6%) (34.8%)
Water saving/ha was calculated at 43.2%
• However, farmers in both questionnaire
survey and discussion groups said that
labor-saving was SRI’s greatest benefit

56. IV. Advantages of SRI
beyond Yield Increases

57. • Cost reduction and increased profitability –
can reduce water, seed, labor and other inputs
• Lower capital requirements – more accessible
for poorer households, help with food security
• Resistence to pests and diseases – farmers can
reduce or end their use of agrochemical sprays
• Resistance to climatic effects – greater tolerance
to drought, cold, storm and salinity, no lodging
• Environmental benefits – less chemical use,
lower water demand, fewer greenhouse gases?
• Lower risk – less chance of net losses from rice
production
• Higher grain quality – higher milling out-turn,
better eating qualities, more nutritious rice?
• Biodiversity conservation – traditional varieties

59. Other Benefits from SRI Methods

61. Two rice fields in Sri Lanka -- same variety,
same irrigation system, and same drought :
conventional methods (left), SRI (right)

63. MEASURED DIFFERENCES IN GRAIN QUALITY
Characteristic SRI (3 spacings) Conventional Diff.
Chalky kernels 23.62 - 32.47 39.89 - 41.07 - 30.7
(%)
General 1.02 - 4.04 6.74 - 7.17 - 65.7
chalkiness (%)
Milled rice 53.58 - 54.41 41.54 - 51.46 + 16.1
outturn (%)
Head milled 41.81 - 50.84 38.87 - 39.99 + 17.5
rice (%)
Paper by Prof. Ma Jun, Sichuan Agricultural University,
presented at 10th conference on Theory and Practice for
High-Quality, High-Yielding Rice in China, Haerbin, 8/2004

64. SRI STILL RAISES MORE
QUESTIONS THAN WE HAVE
ANSWERS FOR
• There are many researchable issues
to be taken up by scientists, in
association with farmers and with
extension personnel
• However, enough is known now to
pursue a two-pronged strategy
with (a) research and (b) practice
proceeding in parallel

65. THANK YOU
Email: ciifad@cornell.edu
or tefysaina.tnr@simicro.mg
Web page:
http://ciifad.cornell.edu/sri/

68. Effects of SRI vs. Conventional Practices
Comparing Varietal and Soil Differences
12
10
8
6 Local-Clay
Local-Loam
4 HYV -Sand
2 Local-Sand
0
All SRI
1/4 SRI
2/4 SRI
3/4 SRI
Practice
Conv.