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The System of Rice Intensification (SRI): Capitalizing on Existing Yield Potentialsby Changing Management Practices
to Increase Rice Productivity with Fewer Inputs and More Profitability
Norman Uphoff, Cornell International Institute for Food, Agriculture and Development (CIIFAD)
World Rice Research Conference, Nov. 7, 2004
What Is SRI?A set of principles & methods to get more productive PHENOTYPES from any existing GENOTYPE of rice
This is accomplished with SRI methods (a) by inducing greater ROOT GROWTH, and (b) by nurturing more abundant and
diverse populations of SOIL BIOTA -- through changing the management of
plants, soil, water, and nutrients
For Centuries, Even Millennia:
• We have FLOODED rice plants, drowning their roots and causing roots to degenerate
• We have CROWDED plants, inhibiting the growth potential of their shoots and roots
• We now apply various FERTILIZERS and AGROCHEMICALS that affect the soil biota
• These provide many services to rice plants: N fixation, P solubilization, protection against diseases and abiotic stresses, etc.
• Standard practices interfere with these benefits
Different Paradigms of Production: • The GREEN REVOLUTION paradigm:
(a) Changed the genetic potential of plants, and(b) Increased the use of external inputs – with more water, more fertilizer, insecticides, etc.
This succeeded, but at fairly high (growing) cost
• SRI just changes the way that farmers manage their plants, soil, water and nutrients, reducing water use and costs of production while raising factor productivity and farmers’ income
• These benefits result from (a) promoting the growth of root systems, and (b) increasing the abundance and diversity of soil organisms, which in turn contribute to plant productivity
SRI Sounds ‘Too Good to be True’ – But It Is True, as seen from papers
• These countries represent over 2/3 of the world’s production/consumption of rice
No longer any question whether SRI works• SRI practices change the E in the G x E
equation: get more productive phenotypes• But there is still much about SRI that is not
well understood – work in progress• Many opportunities for scientific work on soil
biology, plant physiology and nutrition, genetic signaling, disease resistance, etc.
Cambodian farmerwith rice plant grown
from single seed,using SRI methods
and traditional variety
Comparison of Dry Matter Accumulation(kg ha-1) for SRI vs. Control (CK) Practices
at Maturity (Zheng et al., SAAS, 2003)
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Stem Sheath GreenLeaf
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SRICK
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6-J ul 16-J ul 26-J ul 5-Aug 15-Aug 25-Aug
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Figure 1. Change of leaf area index (LAI) during growth cycle (Zheng et al., 2003)
Root Oxygenation Ability with SRI vs. Conventionally-Grown Rice
Research done at Nanjing Agricultural University,Wuxianggeng 9 variety (Wang et al. 2002)
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N-n n-2 Heading Maturity
Development stage
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Plant Physical Structure and Light Intensity Distribution
at Heading Stage (Tao et al., CNRRI, 2002)
SRI
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IH H FH MR WR YRStage
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Yellowleaf andsheathPanicle
Leaf
Sheath
Stem
47.9% 34.7%
Non-Flooding Rice Farming Technology in Irrigated Paddy Field,Dr. Tao Longxing, China National Rice Research Institute, 2004
Roots of a single rice plant (MTU 1071) grown at Agricultural Research Station
Maruteru, AP, India, 2003 season
Two rice plants in Cuba: same variety (VN 2084) and same age (52 days); 42 tillers on SRI plant vs. 5 tillers on the other
ENDOPHYTIC AZOSPIRILLUM POPULATIONS, TILLERING AND RICE YIELDS ASSOCIATED WITH DIFFERENT CULTIVATION
PRACTICES AND NUTRIENT AMENDMENTS Results of replicated trials at the Centre for Diffusion of Agricultural Intensification,
Beforona, Madagascar, 2000 (Raobelison, 2000)
Azospirillum in the
CLAY SOIL Rhizosphere (103/ml)
Roots (103/mg)
Tillers/ plant
Yield (t/ha)
Traditional cultivation, no amendments
25 65 17 1.8
SRI cultivation, with no amendments
25 1,100 45 6.1
SRI cultivation, with NPK amendments
25 450 68 9.0
SRI cultivation, with compost
25 1,400 78 10.5
LOAM SOIL SRI cultivation, with no amendments
25 75 32 2.1
SRI cultivation, with compost
25 2,000 47 6.6
SRI R 2 =
0.6159 Conv
R
2 =
0.3144
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N uptake (kg/ha)
Grain yield (kg/ha)
Grain yield SRI (kg/ha)
Grain yield Conv
(kg/ha)
Poly.:Grain yield
SRI (kg/ha)
Poly.: Grain yield
Conv. (kg/ha)
Rice grain yield response to N uptake
Figure 8: Linear regression relationship between N uptake and grain yield for SRI and conventional methods,
using QUEFTS modeling methodology (Barison, 2002) Results are from on-farm comparisons (N = 108)
Madagascar -- SRI field at Ambatovy, 2003
Sri Lanka – SRI field, 2002, with yield of 13 t ha-1
Cuba -- CPA Camilo Cienfuegos cooperative -- 14 t ha-1
China -- SRI rice field, hybrid variety, Yunnan, 2004 – 18 t ha-1
The System of Rice Intensification • Was evolved in Madagascar over 20 yrs by
Fr. Henri de Laulanié, S.J. – working with farmers, observing, experimenting, also having some luck in 1983-84 season
• SRI is now spreading around the world with positive results in 21+ countries: Bangladesh, Benin, Cambodia, China, Cuba, Gambia, Guinea, India, Indonesia, Laos, Madagascar, Myanmar, Mozambique, Nepal, Peru, Philippines, Senegal, Sierra Leone, Sri Lanka, Thailand, and Vietnam; more to come
• Association Tefy Saina was set up in 1990 to promote SRI; CIIFAD partnership 1994
Fr. de Laulanié not long before he died in 1995
Sebastien Rafaralahy and Justin Rabenandrasana,president and secretary of Association Tefy Saina
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 not needed though it raises SRI yield
Weed control with ‘rotating hoe’ is recommended Farmer innovation is an important part of SRI
Roller-marker devised by Lakshmana Reddy, East Godavari,AP, India, to mark a square pattern on field and save timein transplanting operations; his yield in 2003-04 season
was 16.2 t/ha paddy rice (dry weight)
Seeder developed by Luis Romero, Cuba, for planting
pregerminated seed, sowing 40x40 cm (too wide)
4-row weeder designedby Gopal Swaminathan,
Tamil Nadu, India
Motorizedweeder
developed byS. Ariyaratna,
Sri Lanka
SRI is controversial in some circles• “Niche innovation” (Dobermann, Agric. Systems, 2004) • “Voodoo science” (Cassman and Sinclair, ACSSA, 2004)• “…[SRI] has no major role in improving rice production
generally” (Sheehy et al., Field Crops Research (2004)• “Discussion of SRI is unfortunate because it implies SRI
merits serious consideration. SRI does not deserve such consideration…” (Sinclair, Rice Today, 2004)
However, these critiques are not based on any extended or empirical work with SRI, which is unfortunate
Best refutation is the empirical results that can be reported from many different countries (purpose of this panel)
SRI creates new logic for rice production: Less gives more
LESS CAN PRODUCE MOREby 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• Greater output is possible with use of fewer or even no external/chemical input
when soil communities are unimpaired – living soil is the key to SRI performance
What Are the Negatives?• Labor requirements initially are increased but
with experience, SRI can become: – labor-neutral (GTZ evaluation in Cambodia) or
– even labor-saving (CAU evaluation in China)
• Water control is necessary for best results, but can be achieved through investment/orgzn
• Farmer learning = benefit as much as cost
• Disadoption? – only reported in Madagascar
• Nematodes? – problem in Thailand and Laos
No claim that SRI will be successful everywhere
CAU Evaluation of SRI in Xinsheng Village, Dongxi Township, Jianyang County,
Sichuan Province, August 2004
• 2003 – 7 farmers used SRI (SAAS)
• 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
Xinsheng Village, Dongxi Township RICE YIELD (kg mu-1)
2002 2003* 2004Standard 403.73 297.88 375.77 Methods
SRI -- 439.87 507.16-----------------------------------------------------------SRI Increase (%) +46.6% +34.8%
*Drought year
Water saving/mu -- calculated at 43.2%Farmers said labor-saving greatest benefit
Advantages of SRI – beyond yield• Cost reduction – increased profitability• Lower capital requirements – accessible for poorer
households – food security• Resistence to biotic stresses – less pest and
disease problems, no agrochemicals• Resistance to abiotic stresses – greater drought,
cold, storm and salinity tolerance, no lodging• Environmental benefits – less chemicals, lower
water demand, reduced GHGs?• Biodiversity conservation – tradl. varieties• Grain quality – higher milling outturn, nutrients?
Two rice fields in Sri Lanka -- same variety,same irrigation system, and same drought :
conventional methods (left), SRI (right)
MEASURED DIFFERENCES IN GRAIN QUALITY Characteristic SRI (3 spacings) Conventional Diff.
Chalky kernels (%)
23.62 - 32.47 39.89 - 41.07 - 30.7
General chalkiness (%)
1.02 - 4.04 6.74 - 7.17 - 65.7
Milled rice outturn (%)
53.58 - 54.41 41.54 - 51.46 + 16.1
Head milled rice (%)
41.81 - 50.84 38.87 - 39.99 + 17.5
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
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
Effects of SRI vs. Conventional PracticesComparing Varietal and Soil Differences
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