The System of Rice Intensification (SRI)-- originally the Katayama System of Rice Production

Seminar for the Ministry of Agriculture, Forestry and Fisheries (MAFF)

Tokyo, August 1, 2003Norman Uphoff

Cornell International Institute for Food, Agriculture and Development

WARNING!Some of the data and statistics

you are about to hear or see may appear shocking

Professional discretion is advised

What Is SRI?SRI is a methodology for getting

more productive PHENOTYPES from existing GENOTYPES of rice

by changing the management of Plants, Soil, Water, and Nutrients to

(a) induce greater ROOT growth and

(b) nurture more abundant and diverse SOIL MICROBIAL communities

SRI field in Sri Lanka variety -- panicles have 400+ grains with yield >16 t/ha

SRI plant with 87 fertile tillers(CFA Camilo Cienfuegos, Cuba)

Variety Los Palacios 9 -- 14 t/ha (CFA Camilo Cienfuegos, Cuba)

SRI seems ‘too good to be true’ Changes paradigm of production• GREEN REVOLUTION paradigm:

(a) Changes plants’ genetic potential, and(b) Provides plants with chemical-intensive external inputs -- fertilizer, biocides, etc.

• SRI changes certain management practices:(a) To promote root growth, and(b) To increase the abundance and diversity

of soil microbial populations

Origins of SRI• Developed by Fr. Henri de Laulanie, S.J.

who studied agriculture at ENA (1937-39) before entering a Jesuit seminar in 1941

• Went to Madagascar in 1961, spent next (last) 34 years of his life working with farmers to improve their rice production

• Synthesized SRI practices in 1983-84• This is an example where TECHNOLOGY

leads SCIENCE, as in case of AVIATION

SPREAD OF SRI• Establishment of Association Tefy

Saina in 1990 -- to disseminate SRI within Madagascar, slow progress

• First evaluations outside Madagascar in 1999-2000 -- China (Nanjing Agric. University) and Indonesia (AARD)

• Spread through NGOs, researchers, individuals -- “civil society” innovation

• Scientific understanding SRI growing -- through work of many researchers

OBSERVABLE BENEFITS• Average yields about 8 t/ha --

twice present world average of 3.8 t/ha

• Maximum yields can be twice this -- 15 t/ha or more, occasionally >20 t/ha

• Water requirement is reduced by 50%

• Factor productivity is increased for land, labor, capital and water together

• Costs of production are lowered -- most important to farmers, raise profits

LESS OR NO NEED FOR:• Changing varieties, though best yields

with high-yielding varieties and hybrids -- traditional varieties produce 6-12 t/ha

• Chemical fertilizers -- give a positive yield response with SRI, but the best results are obtained with compost

• Agrochemicals – with SRI methods, plants more resistant to pests and diseases, chemical use not needed

ADDITIONAL BENEFITS• Seeding rate is reduced up to 90%, as

5-10 kg/ha yields more than 50-100 kg

• No lodging because of stronger roots

• Environmentally friendly production due to water saving, no/fewer chemicals

• More accessible to poor households because few capital requirements

• Can be more drought-resistant

DISADVANTAGES / COSTS• SICA is more labor-intensive, at least

initially -- but can become labor-saving• SICA requires greater knowledge/skill

from farmers to become better decision-makers and managers -- this contributes however to human resource development

• SICA requires good water control to get best results, making regular applications of smaller amounts of water -- can gain control with investments & organization?

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. Janaiah Aldas, an economist formerly with IRRI; now at Indira Gandhi Development Research Institute, Mumbai; based on interviews with 30 SRI farmers in Sri Lanka, October, 2002

PHILIPPINES DATA: AGRICULTURAL TRAININGINSTITUTE, DEPARTMENT OF AGRICULTURE,COTOBATO, SRI Field Day, October 28, 2002

Production Analysis PSB Rc 72H PSB Rc 82 PSB Rc 18Plants/m2 = Hills/m2 16 16 16Panicles/hill 20 25.8 31Grains/panicle 191 155 159Grains/hill 3,825 4,822 4,921Yield/m2 1.16 1.25 1.2Yield (t/ha) 11.6 12.5 12.0

Economic Analysis Pesos/ha Pesos/ha Pesos/haInputs: seeds, org. fertiliz. 3,700 3,320 3,320Other expenses 5,830 5,830 5,830Harvesting, threshing 14,848 16,000 15,360 Cost of Production in P/ha

24,378 25,150 24,510

Income from Production @ 8 P/kg

93,800 100,000 96,000

NET PROFIT P/ha 68,422 74,850 71,490 Rate of Return 280% 298% 292%

SRI CAN BE ADAPTED TO UPLAND PRODUCTION

Results of Trials (N=20) by Philippine NGO [ Broader Initiatives for Negros Development ] with Azucena Variety

Spacing Tillers/Hill

PanicleLength

Grains/Panicle

Yield(t/ha)

Net Return(P)

15x40 7.2 30.4 331.2 7.4 2.520x40 9.9 29.4 338.1 7.7 2.925x40 10.2 28.2 315.5 7.4 2.730x40 9.7 29.8 374.9 7.0 2.635x40 11.4 29.2 364.5 6.7 2.4

‘Starting Points’ for SRI• Transplant young seedlings, 8-15 days (2

leaves) -- quickly and very carefully• Single plants per hill with wide spacing in

a square pattern -- 25x25 cm or wider• No continuous flooding of field during the

vegetative growth phase (AWD ok)• Weed with rotating hoe early (10 DAT) and

often -- 2 to 4 times

• Use of compost is recommended/optional • Adapt practices to local conditions

These practices produce a different RICE PHENOTYPE:• Profuse TILLERING - 30 to 50/plant,

80-100 possible, sometimes 100+• More ROOT GROWTH -- 5-6x more

resistance (kg/plant) for uprooting• Larger PANICLES -- 150-250+ grains• Often higher GRAIN WEIGHT-- 5-10%• A POSITIVE CORRELATION between

tillers/plant and grains/panicle

Comparison of high-yield rice in tropical andComparison of high-yield rice in tropical andsubtropical environments: I: Determinants ofsubtropical environments: I: Determinants of

grain and dry matter yieldsgrain and dry matter yieldsJ . Ying, S. J . Ying, S. PengPeng, Q. He, H. Yang, C. Yang,, Q. He, H. Yang, C. Yang,

R. M. R. M. VisperasVisperas, K. G. , K. G. CassmanCassmanField Crops ResearchField Crops Research, 57 (1998), p. 72., 57 (1998), p. 72.

Literature reports: “a Literature reports: “a strongstrong compensation compensationmechanism exists between the two yieldmechanism exists between the two yieldcomponents [panicle number and paniclecomponents [panicle number and paniclesize]” with a “size]” with a “strong negativestrong negative relationship relationshipbetween the two components” (emphasisbetween the two components” (emphasisadded) -- SRI and article show oppositeadded) -- SRI and article show opposite

Plant Physical Structure and Light Intensity Distribution

at Heading Stage (CNRRI Research: Tao et al. 2002)

SRI sounds ILLOGICALLESS CAN PRODUCE MORE -- by utilizingthe potentials and dynamics of biology• Smaller, younger seedlings give larger,

more productive mature plants• Fewer plants per hill and per m2 give

higher yield if used with other SRI practices• Half as much water produces more rice• Greater output possible from using fewer or even no external inputsGet new plant types from existing genomes

Average Yields Impressive --Big Increases Need to be Explained Indonesia -- West Timor (ADRA) • Yield with current methods -- 4.4 t/ha• Yield with SRI methods -- 11.7 t/haPeru -- Pucallpa, jungle area• Previous yields -- 2 t/ha, with more labor• SRI yield -- 8 t/ha, with less labor + ratoon crop 5.5 t/ha = 70% of first cropBenin -- controlled trial: 1.6 vs. 7.5 t/ha

HOW ARE THESE RESULTS ACHIEVED?

(1) Importance of ROOTS

• Rather little scientific research on roots

• Under continuous flooding, 3/4 of rice roots remain in top 6 cm of soil

• Under continuous flooding, roots form air pockets (aerenchyma); these enable rice plants to survive, but cannot thrive

• Under continuous flooding, 3/4 of roots degenerate by time of flowering at start of reproductive phase (Kar et al., 1974)

Dry Matter Distribution of Roots in SRI and Conventionally-Grown Plants at

Heading Stage (CNRRI research: Tao et al. 2002)

Root dry weight (g)

Root Activity in SRI and Conventional Rice Measured by Oxygenation Ability

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

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(2) Importance of SOIL MICROBIAL PROCESSESMicrobial activity is known to be

crucial for 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)

Bacteria, funguses, protozoa, amoeba, actinomycetes, etc.

• Decompose organic matter, making nutrients available

• Acquire nutrients that are unavailable to plant roots

• Improve soil structure and health (water retention, pathogen control)

Biological Nitrogen Fixation• Microorganisms, particularly bacteria,

both aerobic and anaerobic, living around, on and in plant roots can fix nitrogen (N) from air into forms available to plant roots

• Research has shown that when aerobic soil and anaerobic soil are mixed, rather than having only aerobic soil or only anaerobic soil, BNF is greatly increased (Magdoff and Bouldin, 1970)

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

AND NUTRIENT AMENDMENTSResults of 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, withno amendments

25 1,100 45 6.1

SRI cultivation, withNPK amendments

25 450 68 9.0

SRI cultivation, withcompost amendmts

25 1,400 78 10.5

LOAM SOILSRI cultivation, withno amendments

25 75 32 2.1

SRI cultivation, withcompost amendmts

25 2,000 47 6.6

Phosphorus Solubilization• Aerobic bacteria can acquire phosphorus from

unflooded soil for their own use• When the soil is flooded, these bacteria die (lyse)

due to osmotic pressure and release their contents into the soil solution

• When the soil dries again, surviving bacteria begin their growth again

• This cycle of wetting and drying increases the supply of P, and maybe other nutrients, that become available to plants

• MICROBIOLOGICAL WEATHERING PROCESS

Mycorrhizal Associations• Mycorrhizal funguses ‘infect’ plant roots• They send out hyphae (filaments/threads)

in all directions and expand the volume of soil from which the plant can extract nutrients by 10-100 times

• Mycorrhizae are very good at harvesting P -- increase efficiency by as much as 60 x

• Mycorrhizae cannot grow in anaerobic soil conditions, so cannot benefit irrigated rice

Benefits from Rhizobia in rice now documented

• Studied in Egypt where rice and clover grown in rotation, for many centuries

• These endophytic bacteria induce more efficient acquisition of N, P, K, Mg, Ca and Zn in rice (Yanni et al. 2001)

• Rhizobia increase yield and total protein quantity/ha, by producing auxins and other plant-growth promoting hormones (however, no BNF demonstrated)

ROOT EXUDATION IS CRITICAL PROCESS

• Roots are ‘TWO-WAY STREETS’– 40-60% of photosynthate from plants’

canopy is sent down into the plant roots– Much of this is for root metabolism, but

rhizodeposition contributes C to soil– 20-40% of photosynthate sent to roots

gets exuded into soil for microbial support

• Increased bacteria on roots are ‘grazed’ by protozoa -- these ‘excrete’ excess N on root because their C:N ratio is lower

• Other processes augment plant nutrition

(3) Impact of Transplanting YOUNG SEEDLINGS

• Significant effect from transplanting 8-12 day-old seedlings

• Want to avoid any trauma to rice plant, esp. to its roots -- to maintain maximum growth trajectory

• DIRECT SEEDING is an option -- this should be evaluated

PhyllochronPhyllochron is periodic interval of is periodic interval ofgrowth common to all growth common to all gramineaegramineae

In rice, a In rice, a phyllochronphyllochron is usually ~5-8 days long is usually ~5-8 days long In each period, the plant produces In each period, the plant produces one one or moreor morephytomersphytomers from its apical from its apical meristemmeristem

Each Each phytomerphytomer is a unit of is a unit of a a tillertiller, a , a leafleaf andanda roota root -- all growing synchronously -- all growing synchronously

PhyllochronsPhyllochrons represent represent biologicalbiological rather than rather thancalendar time calendar time -- similar to degree days/leaf age-- similar to degree days/leaf age

PhyllochronsPhyllochrons are either lengthened or shortened are either lengthened or shortenedby various factors that can either by various factors that can either slow downslow down or orspeed up speed up the plant’s the plant’s “biological clock”“biological clock”

What speeds up the biological clock?

(adapted from Nemoto et al. 1995)

Shorter phyllochrons Longer phyllochrons• Higher temperatures > cold temperatures• Wider spacing > crowding of roots/canopy• More illumination > shading of plants• Ample nutrients in soil > nutrient deficits• Soil penetrability > compaction of soil• Sufficient moisture > drought conditions• Sufficient oxygen > hypoxic soil conditions

Better growing conditions shorten the phyllochron

• More phyllochrons of growth are then completed before the plant switches from (a) vegetative growth phase to (b) reproductive phase

• More tillering means there is also more root development

Factorial Trials Evaluating 6 Factors

• Variety: HYV (2798) vs. local (riz rouge) or Soil quality: better (clay) vs. poorer (loam)

• Water mgmt: aerated vs. saturated soil

• Seedling age: 8 days vs. 16 or 20 days

• Plants per hill: 1/hill vs. 3/hill

• Fertilization: compost vs. NPK vs. none

• Spacing: 25x25cm vs. 30x30cm (NS diff.)

6 replications: 2.5x2.5m plots (N=288, 240)

Effect of Young Seedlings@ Anjomakely Better Soil Poorer 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

Effects of SRI vs. Conventional PracticesComparing Varietal and Soil Differences

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Local-ClayLocal-LoamHYV -SandLocal-Sand

(4) Importance of Enhancing SOIL ORGANIC MATTER

Through combination of• Compost, mulching, etc. and• Increased root exudation• Monocropping reduces diversity• Value of CROP ROTATION seen

from SRI yields -- highest are from rice grown in rotation w/ potatoes

This helps to solve puzzle

• Why were many Madagascar farmers putting their compost for SRI on their contra-saison crop -- not on rice crop?

• Both crops reportedly gave better yield• This makes no sense if LEACHING and

VOLATILIZATION are big problems, or if nutrients are ‘used up’ by plants

• It makes sense, however, for BNF

OPTIMUM RATES OF N FERTILIZER APPLICATION

Duration Early Medium Late100-110 days 111-120 days 121-135 days

Varieties 60 60 60Optimum NApplication 150-200 150 100Yield (t/ha) 5.36 5.64 5.76

From: J. K. Ladha, G. J. D. Kirk, J. Bennett, S. Peng, C. K.Reddy, P. M. Reddy and U. Singh (1998). Opportunities forincreased nitrogen-use efficiency from improved lowlandgermplasm. Field Crops Research, 56, 41-71.

Effects of Nutrient Amendments: NPK vs. Compost (yield in t/ha)

HYV vs. Local Variety@ Morondava, 2000Sandy soils (sable roux)

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NPK withHYV

Compostwith HYV

NPK withLocal

Compostwith Local

SS/16/ 3SS/16/ 1SS/ 8 / 3SS/ 8 / 1AS/16/ 3AS/16/ 1AS/ 8 / 3AS/ 8 / 1

SRI Supports the Concept of Organic Farming

• Rather than focus our efforts on ‘feeding the plants’ -- we should

• ‘Feed the soil’ -- and let the soil feed the plants

• Focus on symbiosis between plants and soil microorganisms

• Different strategy for agriculture

SRI Raises More Questionsthan we have answers for

• We think many answers will be found in the growth and functioning of Roots, which grow better from

• YOUNG SEEDLINGS, with• WIDE SPACING, and in• AERATED SOIL• Answers also in Soil Microbiology

Thank You for Opportunityto Share this With You

• More information can be obtained from SRI/SICA web site:– http://ciifad.cornell.edu/sri/

• Or from Association Tefy Saina:– tefysaina.tnr@simicro.mg

• Or from me:– ntu1@cornell.edu