The System of Rice Intensification (SRI):

An Overview Cornell International Institute for Food, Agriculture

and Development (CIIFAD)

and Association Tefy Saina, Madagascar

I. AN INTRODUCTION TO SRI

Rice Plants Have More Potential than Has Been Realized Previously• The System of Rice Intensification (SRI) is

a methodology -- not a technology-- for bringing out this potential in rice plants

• It does not depend on purchased inputs -- fertilizer, agrochemicals – saving money

• It does require more labor initially (while learning the methods) and more attention to management, with careful water control

• However, it can become labor saving – saving also water and seed, and reducing risk

• Better grain quality; higher milling outturn

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

Swarna under SRIA single rice plant grown with SRI methods from modern variety (MTU 7029) in Andhra Pradesh, India, 2003-04;usual average yield = 6.55 t/ha; with SRI = 10.20 t/ha

Cambodian rice farmerwith plant grown

from a single seed,using traditional variety

and SRI methods

An SRI field at Ambatovy, Madagascar, 2003

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

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

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

The Basic Ideas of SRI A set of principles and methods that help

farmers get more productive rice plants from ANY VARIETY of rice (i.e., getting

better phenotypes from any genotype)

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

For Centuries, Even Millennia:

• We have FLOODED rice plants, drowning their roots and causing roots to degenerate

• We have CROWDED plants, constraining growth potential of their shoots and roots

• We now apply FERTILIZERS and AGRO-CHEMICALS that affect the life in the soil

• Soil organisms provide many services: N fixation, P solubilization, protection against diseases and climate stresses, etc.

• Usual rice practices interfere with these benefits

Compare Two Different Strategies: • The GREEN REVOLUTION strategy:

(a) Changed the genetic potential of plants, and

(b) Increased the use of external inputs – requiring more water, fertilizer, pesticides, etc.

This succeeded, but at a fairly high (growing) cost

• SRI strategy does neither -- instead it changes how rice plants, soil, water and nutrients are managed– This reduces water requirements and costs of production,

– It also raises the productivity of land, labor, water and capital, so that SRI can raise farmer incomes even more than yield

SRI benefits come from (a) having larger root systems, and (b) greater abundance and diversity of bacteria, fungi, earthworms and other organisms in the soil

SRI Sounds ‘Too Good to be True’ – But It Is True

• Until 1999, SRI was known in only one country (Madagascar)

• In last 5 years, SRI effects have been demonstrated in 20 more countries:– Bangladesh, Cambodia, China, India,

Indonesia, Laos, Myanmar, Nepal, Philippines, Sri Lanka, Thailand, Vietnam

– Benin, Gambia, Guinea, Mozambique, Senegal, Sierra Leone

– Cuba, Peru

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

• Association Tefy Saina was set up in 1990 by Fr. de Laulanie with friends to promote SRI and rural development in Madagascar

• CIIFAD began working with Tefy Saina in 1994; CIIFAD did not accept SRI until 1997 after farmers who had been getting 2 t/ha averaged 8 t/ha for three years with SRI

Fr. de Laulanié not long before he died in 1995

Sebastien Rafaralahy and Justin Rabenandrasana,president and secretary of Association Tefy Saina

Spread of SRI Has Been Rapid• First demonstrations of SRI were in 1999:

– Nanjing Agricultural University in China– Indonesian Rice Research Institute at Sukamandi

• Since then: NGOs, universities, farmer organizations, govt. research institutes and others have taken an interest in SRI -- testing it, evaluating it, and disseminating it

• Also improving on it, adapting it to local conditions – SRI is a “work in progress”

• Farmer innovation is encouraged• Leading research institutions in China, India

and Indonesia have accepted SRI based on their years of evaluation

What Are the Negatives?• Labor requirements are initially increased (25-

50%) but with experience, SRI can become: – labor-neutral (GTZ evaluation in Cambodia) or

– labor-saving (CAU in China; TNAU in India)

• Water control is necessary for best results, but can be done thru investment & organization

• Farmer learning is a benefit as well as a cost

• Disadoption? – only reported in Madagascar

• Nematodes? – problem in Thailand, elsewhere?

No claim that SRI will be successful everywhere

SRI goes against usual logic: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 can 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

• Lliving soil is the key to SRI performance

II. Evidence on SRI Changes in Plant Growth

Initial Skepticism Was Warranted

• SRI results are remarkable, sometimes beyond what has been considered as the ‘biological maximum’ for rice

• But growing body of research evidence, especially from China, documents that SRI practices induce physiological changes in rice plants that make them more productive; SRI is no magic -- all is can be explained in scientific terms

Study by China National Rice Research Institute, Hangzhou

• Comparison of SRI vs. standard methods (CK = check or control) with 2 different varieties of rice

• Measuring leaf area and dry matter at different levels of the shoot (plant above ground)

• Both varieties respond positively to SRI methods: Liangyoupeijiu responds more

Plant Physical Structure and Light Intensity Distribution

at Heading Stage (Tao et al., CNRRI, 2002)

Evaluations Done by Sichuan Academy of Agricultural Sciences in China

• Measurements were made compare the same variety of rice growth with SRI or with conventional (CK) methods

• The leaf area index (LAI) was measured at different stages during growth cycle

• Dry matter accumulation in different plant organs was measured at different stages – the results are shown here for the rice plant at maturity

2

3

4

5

6

7

8

6-J ul 16-J ul 26-J ul 5-Aug 15-Aug 25-Aug

Date

LAI

SRICK

Figure 1. Change of leaf area index (LAI) during growth cycle (Zheng et al., 2003)

Dry Matter Accumulation betweenSRI and Control (CK) Practices (kg/ha)at Maturity (Zheng et al., SAAS, 2003)

0

5000

10000

15000

20000

25000

30000

Stem Sheath GreenLeaf

With.Leaf

Panicle Biomass

SRICK

Researchers at Nanjing Agricultural University in China Studied Roots

• Using the same variety (Wuxianggeng 9), rice plants were grown with SRI (S) and usual methods (W) under controlled conditions

• At different growth stages -- effective tillering, jointing, heading, and maturity -- a chemical compound (ά-naphthylamide) was measured in the roots to assess their oxygenation ability

• Throughout the growth cycle, his compound was 2-3 times higher in the SRI plant roots, reflecting greater SRI root activity

Root Oxygenation Ability with SRI vs. Conventionally-Grown Rice

Research done at Nanjing Agricultural University,Wuxianggeng 9 variety (Wang et al. 2002)

0

100

200

300

400

500

N-n n-2 Heading Maturity

Development stage

Oxyg

enati

on ab

ility o

f α-

NA(u

g/h.gD

W)

W

S

Researchers at the China National Rice Research Institute Assessed the Dry

Matter in Different Plant Organs

• The dry weight of above-ground organs was compared at different growth stages:– Stem – Sheath– Leaf– Panicle (grain ear)– Senescent leaf and sheath (shown in yellow)

• The differences in phenotype seen in pictures can be shown in graphic form:

SRI

0

50

100

150

200

250

300

IH H FH MR WR YRStage

Org

an d

ry w

eigh

t(g/

hill)

CK

IH H FH MR WR YR

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

Root Research in Madagascar• Research by Barison (1998) found that it took

28 kg of force to pull up clump of 3 rice plants conventionally grown, on average

• Single SRI plants, however, required 53 kg each -- >5 times more force per plant

• Research in 2001 measured root length density (cm of roots per cm3) at different depths in soil, comparing (1) SRI methods with and without compost; (2) improved methods (SRA) with and without fertilizer; and (3) conventional practice

• At 30-50 cm depth, SRI roots were twice as much

Table 13: Root Length Density (cm/cm3) under SRI, ‘Modern’ (SRA) and Conventional Practices (Barison, 2002)

Results from replicated on-station trials

TreatmentsSoil layers (cm)

0-5 5-10 10-20

20-30

30-40

40-50

SRI -- with compost 3.65 0.75 0.61 0.33 0.30 0.23

SRI -- without compost 3.33 0.71 0.57 0.32 0.25 0.20

SRA with NPK and urea 3.73 0.99 0.65 0.34 0.18 0.09

SRA without fertilization 3.24 0.85 0.55 0.31 0.15 0.07

Conventional practice 4.11 1.28 1.19 0.36 0.13 0.06

These differences are easy to see• Farmers, extension personnel and

researchers should all get in the habit of examining roots – this is seldom done!

• Size of root system, length of roots, and their color should be inspected – white color indicates healthy roots, not black color and dying back for lack of oxygen

• Next slide shows the kind of root growth that is possible with SRI methods

Roots of a single rice plant (MTU 1071) grown at Agricultural Research Station

Maruteru, AP, India, 2003 season

Two plants on left were started in same nursery as plant onright, but were transplanted into SRI conditions at 9 days.

They are the same variety (VN 2084) and same age (80 days)

Plants from farm of LuisRomero, San Antoniode los Baños, Cuba

Modeling Analysis of Yield Response to Nutrient Uptake

• Barison used QUEFTS model to analyze rice plants and yield with SRI or usual methods on 108 farms in Madagascar where farmers used both methods – to have both farms and farmers the same

• The efficiency of plants is very different as SRI plants give about twice as much grain for uptake of N (also P and K)

SRI R 2 =

0.6159 Conv

R

2 =

0.3144

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0 100 200

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)

Changes within the Roots• This research is just beginning, but a

study in 2002 showed dramatic changes in the populations of a nitrogen-fixing bacteria (Azospirillum) in rice roots in response to SRI changes in plant, soil, water and nutrient management

• These were associated with large change in yield: from 1.8 t/ha with conventional methods to 10.5 t/ha with all-SRI practice (results are averages for 6 replications)

• Fertilizer gave good results; but compost gave even better results

ENDOPHYTIC AZOSPIRILLUM POPULATIONS, TILLERING AND RICE YIELDS ASSOCIATED WITH DIFFERENT CULTIVATION

PRACTICES AND NUTRIENT AMENDMENTS Results of replicated trials on farms at Anjomakely, Madagascar, for agronomy thesis

for School of Agriculture (ESSA) at University of Antananarivo (Andriakaja, 2000) Yield and tiller data are from 6 replications of different combinations of practices.

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

Analysis of Effects on PlantDr. T. M. Thiyagarajan, Tamil Nadu

Agricultural University, did analyses of SRI and conventionally-grown plants at TNAU experimental farm during 2001-2002 cropping year– Variety CORH-2 (125 d) in wet season,– Variety ADTRH-1 (115 d) in dry season

With the following results showing strong differences in different aspects of plant physiology

Effects of SRI on crop physiologyWet Season (2001-02) Dry Season (2002)

Conventional SRI Conventional SRI

Total chlorophyll (mg g-1)

2.76 3.20 2.60 3.13

Soluble protein (mg g-1)

8.35 12.62 10.25 11.95

Nitrate reductase (mg NO2g-1 h-1)

12.42 18.11 11.74 16.70

Root CEC (mg 100g-1)

- - 8.40 11.23

Cytokinins (pmol g-1)

- - 56.77 72.47

Scientific Studies Are Increasing• Numbers (totals, averages, rates, etc.)

will vary for different soils, varieties, climatic conditions, water mgmt, etc.

• SRI depends on biological processes, which means that results can vary widely depending upon the growing conditions

• Challenge is to explain remarkable results• The results are real and often repeated• Farmers, scientists and extension staff

should work together to be better able to advance knowledge and practice

THANK YOU

Email: ciifad@cornell.eduor tefysaina.tnr@simicro.mg

Web page: http://ciifad.cornell.edu/sri/