1. The System of Rice Intensification (SRI): Understanding an
Opportunity to Raise Rice Sector Productivity Norman Uphoff, CIIFAD
Cornell University, USA
2. For Centuries, Even Millennia, We Have Been ABUSING and
MISTREATING the Rice Plant
We have FLOODED it drowning its roots
We have CROWDED it inhibiting the growth potential of its
canopy and roots
Now we apply FERTILIZERS and chemical BIOCIDES that suppress or
kill soil biota which provide many services to the plants
Bacteria, fungi, etc. provide N fixation, P solubilization,
disease protection, etc.
3. The System of Rice Intensification
Evolved in Madagascar over 20-yr period by Fr. Henri de
Laulani, S.J. through working with farmers, observing, doing
experiments, also having some luck
SRI synthesized 20 years ago (1983-84) now spreading around the
world
SRI is a set of principles and insights translated into certain
practices that change the growing environment of rice to get
healthier, more productive plants
These principles were developed in China as the 3S system same
ideas/concepts
4. Canopy of an individual rice plant grown under SRI
conditions; this variety (Swarna) is normally shy-tillering Andhra
Pradesh, India, Rabi season, 2003-04
5. Roots of a single rice plant (MTU 1071) grown at
Agricultural Research Station Maruteru, AP, India, Kharif 2003
6. SRI field in Sri Lanka -- yield of 13 t/ha with panicles
having 400+ grains
7. CFA Camilo Cienfuegos, Cuba 14 t/ha -- Variety Los Palacios
9
8. SRI (3S) in Summary : A set of principles/methods to get
more productive PHENOTYPES from any existing GENOTYPE of rice. SRI
(3S) changes the management of plants, soil, water, and nutrients
to (a) induce greater ROOT growth and (b) nurture more abundant and
diverse populations of SOIL BIOTA
9. Plant Physical Structure and Light Intensity Distribution at
Heading Stage (CNRRI Research --Tao et al. 2002)
10. Dry Matter Accumulation between SRI and Control (CK)
Practices (kg/ha) at Full Heading (Zheng et al., SAAS, 2003)
11. Dry Matter Accumulation between SRI and Control (CK)
Practices (kg/ha) at Maturity (Zheng et al., SAAS, 2003)
12. Table 2. Different sizes of the leaf blade (cm) (Zheng et
al., SAAS, 2003) 11.98 15.95 7.96 18.49 19.11 14.97 9.79 14.59 %
0.20 8.86 0.16 9.00 0.30 9.29 0.14 8.18 +/- 1.67 55.56 2.01 48.67
1.57 62.03 1.43 56.07 CK 1.87 64.41 2.17 57.67 1.87 71.32 1.57
64.25 SRI Width Length Width Length Width Length Width Length
Average Flag leaf 2 nd leaf 3 rd leaf Item
13. Figure 1. Change of leaf area index (LAI) during growth
cycle (Zheng et al., 2003)
14. Different P aradigms of Production
The GREEN REVOLUTION paradigm:
(a) Change the genetic potential of plants, and
(b) Increase the use of external inputs -- more water,
fertilizer, insecticides, etc.
SRI changes certain management practices for plants, soil,
water and nutrients so that:
(a) Root growth is promoted , and
(b) Abundance & diversity of soil microbial populations --
also soil fauna are increased
Reduce WATER and COSTS OF PRODUCTION
15. Greatest Benefit Is not YIELD
Yield varies , often widely -- besides, for farmers,
profitability is more important
From societys perspective, what is most important is factor
productivity kg per land, labor, capital, and water !
Rather than focusing on yield, I want to consider possible
explanations for SRI results try to advance science for rice
Some of what I say will have evidence & support --
otherwise strong hypotheses
16. SRI Practices Should Always be Varied to Suit Conditions
Four basic elements of SRI practice:
Young seedlings are used -- DS an option
Wide spacing single plants, square pattern
Soil aeration thru water management and weeding, so aerobic
conditions prevail in soil
Organic matter to be enhanced in the soil fertilizer not needed
if compost is used
Recommend weed control with rotating hoe
These are the basic ideas for SRI practice
17. Explanations: 1. Above-Ground Environment
Create the edge effect for the whole field
Only avoid edge effect for measurement; promote it
agronomically (triangle spacing)
Too close spacing affects photosynthesis within canopy:
measurements at AARD (Sukamandi, Indonesia) found that with normal
spacing, lower leaves had to be subsidized by upper leaves; but
wider spacing enables whole plant to contribute
18. Explanation: 2. Nitrogen Provision
Rice yields increased 40-60% when same amount of N provided
equally in both NO 3 and NH 4 forms vs. when all N is provided as
NH 4 (Kronzucker et al., 1998)
BNF increases greatly with alternated aerobic/anaerobic
conditions (Magdoff and Bouldin, Plant and Soil , 1970)
Contributions of protozoa to N supply?
Also contributions from endophytes ?
19.
20. Explanations: 3. Phosphorus Solubilization
This nutrient is often limiting factor
Large amounts of P in soil (90-95%) are in unavailable
form
Alternating wetting and drying of soil increased P in soil
solution by 85-1900% compared with soils just wet or just dry
(Turner and Haygarth, Nature , May 2001)
Aerobic bacteria acquire P from unavailable sources during dry
phase; during wet phase they lyse and release P into the soil
solution
21. Explanations: 4. Mycorrhizal Fungi
90+% of terrestrial plants derive benefits from and even depend
on mycorrhizal associations (infections)
Mycorrhizal hyphae (filaments) extend into soil and expand
volume accessible to the plant by 10-100x , acquiring water, P and
other nutrients , also providing protective/other services
Flooded rice forgoes these benefits
22. Explanations: 5. Phytohormones
Aerobic bacteria and fungi produce auxins, cytokinins,
gibberellins , etc. in the rhizosphere
Huge literature has documented effects of microbially-produced
phytohormones (e.g., Frankenberger and Arshad, 1995)
Root growth in SRI plants probably are not just due to
physiological processes within the plants, but are stimulated by
aerobic microorganisms? Roots are key
23. Single Cambodian rice plant transplanted at 10 days
24. Cuba -- Variety VN 2084 (Bolito) -- 52 DAP
25. Dry Matter Distribution of Roots in SRI and
Conventionally-Grown Plants at Heading Stage (CNRRI research: Tao
et al. 2002) Root dry weight (g)
26. Table 13: Root Length Density (cm. cm -3 ) under SRI,
Modern (SRA) and Conventional Practice (from Barison, 2002) Results
from replicated on-station trials 0.06 0.13 0.36 1.19 1.28 4.11
Conventional practice 0.07 0.15 0.31 0.55 0.85 3.24 SRA without
fertilization 0.09 0.18 0.34 0.65 0.99 3.73 SRA with NPK and urea
0.20 0.25 0.32 0.57 0.71 3.33 SRI -- without compost 0.23 0.30 0.33
0.61 0.75 3.65 SRI -- with compost 40-50 30-40 20-30 10-20 5-10 0-5
Soil layers (cm) Treatments
27. Figure 8: Linear regression relationship between N uptake
and grain yield for SRI and conventional methods, using QUEFTS
modeling (from Barison, 2002) Results are from on-farm comparisons
(N = 108)
28. Figure 9: Estimation of balanced N uptake for given a grain
yield for rice plants with the SRI and conventional systems, using
QUEFTS modeling (same for P and K) (Barison, 2002) Results are from
on-farm comparisons (N = 108)
29. Root Oxygenation Ability with SRI vs. Conventionally-Grown
Rice Research done at Nanjing Agricultural University, Wuxianggeng
9 variety (Wang et al. 2002)
30. What Are Problems for SRI?
Labor Requirements initially more labor-intensive --
25-50%
As farmers gain skill & experience, this is reduced, and
SRI can even become labor-saving
GTZ evaluation of SRI in Cambodia: no difference in labor
requirements (305 vs. 302 hrs/ha) better timing
CEDAC evaluation: 55% say easier
31. Roller-marker devised by Lakshmana Reddy, East Godavari,
AP, India, to save time in transplanting operations; his yield in
2003-04 rabi season was 16.2 t/ha paddy (dry weight)
32. 4-row weeder designed by Gopal Swaminathan, Thanjavur, TN,
India
33. Motorized weeder developed by S. Ariyaratna Sri Lanka
34. Adjustable-width weeder designed by Hari R., Moramanga,
Madagascar (from IRRI design)
35. Labor-Saving Methods of Crop Establishment
Tray methods being developed in China, also in Cuba
Sowing/Thinning methods started in India and Sri Lanka
broadcasting pregerminated seed (25 kg/ha) or young seedlings --
then weed as usual , creating wide spacing with a square pattern
(sacrifice seed for labor)
36. Seeder Developed in Cuba
37. What Are Problems for SRI?
2. Water Control needed to get the best results with SRI
methods
This constraint but can be reduced by investment in physical
facilities or in organization and management
Most rice-growing countries will need to reduce the allocations
of water for rice sector in coming yrs
SRI can help reduce water demand
38. Emerging Benefits of SRI?
1. Resistance to Abiotic Stresses climate becoming more extreme
and more unpredictable
Observed resistance to drought (Sri Lanka, several years) ,
hurricane (Sichuan Sept. 2002) , typhoon (AP, India Dec. 2003) ,
cold spell (AP, India February 2004)
Resistance to lodging due to roots?
39. Two rice fields in Sri Lanka -- same variety, same
irrigation system, and same drought : conventional methods (left),
SRI (right)
40. Emerging Benefits of SRI?
2. Resistance to Pests and Diseases widely reported by farmers
probably reflecting the protective services of soil
microorganisms
3. Higher Milling Outturn by ~ 15%: SRI paddy raises outturn in
India from 66 to 75%; and in Cuba, from 60 to 68-71%
Fewer unfilled grains (less chaff)
Fewer broken grains (less shattering)
41. Emerging Benefits of SRI?
4. Higher Nutritional Value of Rice?
Can have organic rice that is free from agrochemical
residues
Quite possibly also higher nutritional quality in terms of
micronutrients needs to be evaluated scientifically
Larger root system gives higher grain weight (usually 5-15%
higher), also greater grain density and nutrients?
42. Emerging Benefits of SRI?
5. Conservation of Rice Biodiversity ?
Highest SRI yields come with HYVs and hybrids all of the yields
>15 t/ha
Traditional / local varieties respond very well to SRI, can
produce yields of 6-10 t/ha, and even more
Traditional rice receives higher price; higher SRI yields make
them popular; organic premium is good for export
43.
44. SRI sounds ILLOGICAL
BUT LESS CAN PRODUCE MORE by utilizing biological potentials
& processes
Smaller, younger seedlings become larger, more productive
mature plants
Fewer plants per hill and per m 2 will give higher yield if
used with other SRI practices
Half as much water produces more rice because aerobic soil
conditions are better
Greater output is possible with use of
fewer or even no external/chemical inputs
Get a different phenotype from rice genome
45. SRI RAISES MORE QUESTIONS THAN WE HAVE ANSWERS FOR
This should please scientists lot of interesting new work
ahead
At present, Chinese scientists have done more scientific
research on SRI than anybody else
Hope to accelerate this and link with more work around the
world
46. SRI Experience Could Help to Us to Improve 21 st Century
Agriculture
Nurturing of roots and soil biota is relevant for most of
agriculture
Need agriculture that is
Less thirsty -- better roots will help
Less dependent on fossil-fuel energy sources -- fertilizer,
mechanization
Less dependent on agrochemicals -- for sake of soil & water
quality, for health
47. Thank You for Opportunity to Share Ideas With You
More information can be obtained from SRI web site:
http://ciifad.cornell.edu/sri/
Or from Association Tefy Saina:
[email_address]
Or from CIIFAD/Norman Uphoff:
[email_address]
48.
49.
50. SRI Data from Sri Lanka
SRI Usual
Yields (tons/ha) 8.0 4.2 +88%
Market price (Rs/ton) 1,500 1,300 +15%
Total cash cost (Rs/ha) 18,000 22,000 -18%
Gross returns (Rs/ha) 120,000 58,500 +105%
Net profit (Rs/ha) 102,000 36,500 +180%
Family labor earnings Increased with SRI
Water savings ~ 40-50%
Data from Dr. Aldas Janaiah, IRRI agric. economist, 1999-2002;
now at Indira Gandhi Development Research Institute in Mumbai;
based on interviews conducted with 30 SRI farmers in Sri Lanka,
October, 2002
51. IWMI Data from Sri Lanka
IWMI Evaluation (Namara, Weligamage, Barker 2003)
60 SRI and 60 non-SRI farmers randomly selected:
YIELD -- increased by 50% on average (not doing full SRI)
WATER PRODUCTIVITY -- increased by 90%
COST OF PRODUCTION (Rs./kg) -- lower by 111-209% with family
labor, 17-27%at standard wage rate
LABOR PRODUCTIVITY (kg/hr) -- up 50% in yala (dry) season, up
62% in maha (wet) season
PROFITABILITY -- increased by 83-206%, depending on the wage
assumed (family labor vs. paid labor)
RISK REDUCTION -- conventional farmers had net losses in 28% of
seasons, SRI farmers in only 4%
52.
53. SRI CONCEPTS CAN BE EXTENDED TO UPLAND PRODUCTION Results
of trials (N=20) by Philippine NGO, Broader Initiatives for Negros
Development, with Azucena local variety (4,000 m 2 area) -- using
mulch as main innovation, not young plants
54. (1) ROOT SYSTEM PROMOTION
SRI is becoming referred to in India (AP) as the root
revolution -- key factor
Roots benefit from wider plant spacing, aerated soil, more soil
organic matter --from both compost and root exudation
Roots are supported by more abundant and diversified
populations of soil biota -- bacteria and viruses produce PGRs
Plants are two-way streets , coevolved w/ microorganisms,
dependent on them
55. SRI farmer in Cambodia
56. SRI farmer in Cuba -- 14 t/ha
57. Root Research Reported by Dr. Ana Primavesi (1980)
Shoot and root growth of maize (in g) grown in hydroponic
solutions (14 days), with varying nutrient concentrations
Shoot Root
100% concentration 44 7
200% concentration 34 7
2% concentration 33 23
2% concentration when 43 56 changed every other day
58. (2) Contribution of SOIL MICROBIAL PROCESSES
Microbial activity is known to be crucial factor in soil
fertility
The microbial flora causes a large number of biochemical
changes in the soil that largely determine the fertility of the
soil. (DeDatta,1981, p. 60, emphasis added)
59. Bacteria, funguses, protozoa, amoeba, actinomycetes, etc.
Decompose organic matter , making nutrients available
Acquire nutrients otherwise unavailable to plant roots
Improve soil structure and health -- water retention, soil
aggregation, aeration, pathogen control, etc.
60. Known Processes
Biological nitrogen fixation (BNF) ** -- also productivity from
mix of NO 3 > all NH 4
Phosphorus (P) solubilization **
Nutrient acquisition increases through mycorrhizal fungi
associations with roots
Rhizobia bacteria produce hormones promoting root growth -
increase yield, protein
Protozoa graze on bacteria on roots and excrete excess N --
because of lower C:N ratio
* * Both increased by wetting and drying of soil
61. (3) Impact of Transplanting YOUNG SEEDLINGS
Big effect from transplanting seedlings 8-12 days old = during
the 2nd or 3rd phyllochron, before 4th phyllochron (explained by T.
Katayama, 1920s-30s)
Avoid trauma to rice plant, especially to its roots , for
maximum growth trajectory
DIRECT SEEDING is possible, however -- being experimented with
to save labor
62.
63. Effect of Young Seedlings
@ Anjomakely Clay Soil Loam Soil
SS/20/3/NPK 3.00 2.04
SS/ 8 /3/NPK 7.16 3.89
SS/ 8 / 1 /NPK 8.13 4.36
AS / 8 /3/NPK 8.15 4.44
AS / 8 /3/ Comp 6.86 3.61
SS/ 8 / 1 / Comp 7.70 4.07
AS / 8 / 1 /NPK 8.77 5.00
AS / 8 / 1 / Comp 10.35 6.39
Note: All of these averages are for 6 replicated trials
64. Effects of SRI vs. Conventional Practices Comparing
Varietal and Soil Differences
65. Conclusions
SRI taps available genetic potentials
The methods can be most accessible to the poor to improve food
security , but gaining with large farmers (44 ha)
The methodology is environmentally friendly and economically
profitable
SRI still raises more questions than answers -- contribute to
new paradigm?
SRI is still evolving , through farmer innovation and research
evaluations
66. Conclusions (continued)
SRI work proceeding on 2 tracks :
Farmer/NGO experimentation/extension
Scientific investigations/evaluations
SRI experience may have implications for improving other crop
production :
Improve the ROOT GROWTH of crops
Support SOIL BIOTA for plants benefit
SRI could contribute to a post-modern agriculture -- most
modern agriculture because based on biological sciences
67. Conclusions (continued)
SRI is not finished -- still evolving, changing, spreading, so
it is premature to make final judgment or evaluation
SRI methods will not be suitable everywhere -- but not a niche
innovation; suitable in all 22 districts of Andhra Pradesh
SRI is not speculation -- not wishful thinking -- but a
FACT
Question is: what use will be made of these new insights and
opportunities?
68. Spread of SRI in Asia
69. Spread of SRI in Africa
Madagascar : now 50,000-100,000 farmers, average about 6-8
t/ha, some double or more
Sierra Leone : 2.5 5.3 t/ha for 160 farmers
The Gambia : 2.5 7.4 t/ha for 10 farmers
Benin : 1.6 7.5 t/ha in controlled trial
Guinea : 2.5 9.4 t/ha (hybrid + SRI)
Interest in, but no results yet from: Ethiopia, Ghana, Mali,
Mozambique, Senegal, South Africa, Tanzania, and Uganda
70. Spread of SRI in Latin America
Cuba : average 8-9 t/ha; INCA trial 12 t/ha; a number of
farmers have reached 14 t/ha
Peru : initial problems with drought, frost; 2003 results 9-11
t/ha vs. current average of 6 t/ha ( not profitable given costs of
production)
Interest in, but no results yet from: Barbados, Brazil,
Colombia, Dominican Republic, Guyana, and Venezuela