0893 Conventional Rice vs SRI - Prospects

Conventional Rice vs SRI Conventional Rice vs SRI - - ProspectsProspects

S.RamasamyProfessor (Agronomy)

Tamil Nadu Agricultural University,

Coimbatore, INDIA 641 003

[email protected]

Presenting on..Presenting on.. Rice cultivation in India and Tamil NaduRice cultivation in India and Tamil Nadu Farmers’ way of rice cultivationFarmers’ way of rice cultivation Potential yieldPotential yield Root activity and yieldRoot activity and yield Best Management Practices for riceBest Management Practices for rice SRI vs. conventional practiceSRI vs. conventional practice

Experimental yield levelsExperimental yield levels Advantages of SRIAdvantages of SRI Constraints in SRIConstraints in SRI Modifications in SRIModifications in SRI A modified SRI – DPSA modified SRI – DPS

ConclusionConclusion

Rice cultivation in IndiaRice cultivation in India 40 + million ha with average yield of 2t ha40 + million ha with average yield of 2t ha Variety of crop establishmentsVariety of crop establishments

LowlandLowland Transplanted – good yieldTransplanted – good yield Direct wet-seeded – weed menaceDirect wet-seeded – weed menace Dry-seeded and rainfedDry-seeded and rainfed

Upland – soil and nutrient losses, poor yieldUpland – soil and nutrient losses, poor yield Lowland rice - major areasLowland rice - major areas

Punjab - 3.3 t/haPunjab - 3.3 t/ha Tamil Nadu – 3.2 t/haTamil Nadu – 3.2 t/ha AP and WB with large areas under wet AP and WB with large areas under wet

ecosystemecosystem

Rice scenario - in the state of TNRice scenario - in the state of TN

2.0 m ha2.0 m ha Cultivation throughout the yearCultivation throughout the year

Irrigated and rainfedIrrigated and rainfed Single rice season: August – Dec, JanSingle rice season: August – Dec, Jan

Major areaMajor area

Double rice season irrigatedDouble rice season irrigated June – Sept,; again Oct- FebJune – Sept,; again Oct- Feb June – Sept,; again Dec- MarchJune – Sept,; again Dec- March

June- Sept.: Dry seasonJune- Sept.: Dry season Aug- Jan: Wet season Aug- Jan: Wet season

Rice scenario - in the state of TN..Rice scenario - in the state of TN..

Wet seasonWet seasonMajor area (80%)Major area (80%)Medium and long-duration riceMedium and long-duration riceHigher biomass but poor HIHigher biomass but poor HI

Dry seasonDry seasonAround 20% areaAround 20% areaShort-durationShort-durationHigher yield than wet seasonHigher yield than wet seasonHigher HIHigher HI

Farmers’ way of rice cultivationFarmers’ way of rice cultivation

High seed rate and thick nurseryHigh seed rate and thick nurseryMore than 30-day-old seedlingsMore than 30-day-old seedlingsPoor field levelingPoor field levelingRandom plantingRandom planting

Farmers way of rice cultivationFarmers way of rice cultivation

High seed rate and thick nurseryHigh seed rate and thick nurseryMore than 30 days old seedlingsMore than 30 days old seedlingsPoor field levelingPoor field levelingRandom plantingRandom planting

Farmers’ way of rice cultivation.Farmers’ way of rice cultivation.

Clump of seedlings per hillClump of seedlings per hillDeep plantingDeep planting

Farmers’ way of rice cultivation..Farmers’ way of rice cultivation..

MeritsMeritsPlant the entire area in short periodPlant the entire area in short periodNo land left fallow for want of seedlingsNo land left fallow for want of seedlingsGap filling is avoidedGap filling is avoidedWeeds are managed with less effortWeeds are managed with less effortRisk of failure is minimumRisk of failure is minimum

Farmers’ way of rice cultivation…Farmers’ way of rice cultivation…

De-meritsDe-meritsUneven plant standUneven plant standMechanical weeding is not possibleMechanical weeding is not possible Irrigation regime varies within the fieldIrrigation regime varies within the fieldPoor nutrient managementPoor nutrient managementRisk of pests and disease out breakRisk of pests and disease out breakPoor harvest indexPoor harvest index


Higher yield obtained by farmersHigher yield obtained by farmersMaximum yield competitionMaximum yield competition

Increased from 12 t /ha in early 80s to Increased from 12 t /ha in early 80s to > 20 t/ha in 1990s> 20 t/ha in 1990s

Higher yields reported were in:Higher yields reported were in: Wet seasonWet season Higher green manuresHigher green manures Not from the traditional deltaNot from the traditional delta But not repeatedBut not repeated


Higher yields obtained by farmers Higher yields obtained by farmers were not repeated once…were not repeated once…Reasons remain fuzzy!!!Reasons remain fuzzy!!!Could be that proper soil and water Could be that proper soil and water

management prevailed in that periodmanagement prevailed in that period In drought /dry season get better yieldIn drought /dry season get better yieldThere are There are marked differencesmarked differences between between

dry and wetdry and wet seasons seasons

Dry season Dry season vsvs.. Wet season Wet season

Dry seasonDry season Wet seasonWet season

Period (days)Period (days) Jun- SepJun- Sep Aug, Sep - Dec, JanAug, Sep - Dec, Jan

DurationDuration 105105 135135

Mean Temp Mean Temp °°CC 30+30+ 25+25+

Solar radiationSolar radiation 450 cal450 cal 450 cal450 cal

Total biomass t/haTotal biomass t/ha 13-1713-17 16-1816-18

Grain yieldGrain yield – – StateState 3.33.3 2.32.3

Grain yieldGrain yield – Expt – Expt 6-86-8 5-75-7

Ratio: Ratio: PTPT/ / TTTT HighHigh LowLow

% grains/panicle% grains/panicle HighHigh LowLow

RootRoot color color WhiteWhite to to brownbrown BrownBrown to to blackblack

Root activityRoot activity Fairly goodFairly good After PI sharply fallingAfter PI sharply falling

Probable reasonProbable reason Less standing waterLess standing water Continuous inundationContinuous inundation

Potential yield is achievable..Potential yield is achievable..

When all the resources are available freelyWhen all the resources are available freely Root activity decides the yield levelRoot activity decides the yield level

It is not the It is not the total shoot biomasstotal shoot biomass before before heading that determined yield so much as heading that determined yield so much as the photosynthesis (>the photosynthesis (>6060%) and the %) and the translocation (>translocation (>3030%) after heading%) after heading

To maintain photosynthesis until the final To maintain photosynthesis until the final spikelets are filled completely, spikelets are filled completely, roots should roots should be activebe active, irrespective of quantity of roots , irrespective of quantity of roots

Root activityRoot activity

Root activity remains fairly good when Root activity remains fairly good when internal field drainage does exist internal field drainage does exist

Root activity and total biomassRoot activity and total biomass

0

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14000

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0 23 33 43 53 63 74 84 91

No

Drainage

Ramasamy et al 1997

Root activity and root colorRoot activity and root color

Ramasamy et al 1997

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

AT PI FF MR AT PI FF MR

Black

Brown

White

No drainage With Drainage

Effect of drainage on grain yield Effect of drainage on grain yield

Ramasamy et al 1997

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

Dry 90 Wet 90-91 Dry 91

Dn - N 100

Dn - N 150

Dn - N 200

Dw - N 100

Dw - N 150

Dw - N 200

No Drainage

With Drainage


Root activity remains fairly good when Root activity remains fairly good when internal field drainage does existinternal field drainage does exist

Internal field water movement Internal field water movement alone is alone is not sufficientnot sufficient if the if the soil is ill-drained soil is ill-drained and highly organicand highly organic or applied with or applied with organic materialorganic material

Root activity..Root activity..

Root activity remains fairly good when Root activity remains fairly good when internal field drainage does existinternal field drainage does exist

Internal field water movement alone is Internal field water movement alone is not sufficient if the soil ill-drained and not sufficient if the soil ill-drained and highly organic or applied with organic highly organic or applied with organic materialmaterialMechanical stirring can expel out Mechanical stirring can expel out

chemicals formed due to decaychemicals formed due to decay


Root activity remains fairly good when internal field Root activity remains fairly good when internal field drainage does existdrainage does exist

Internal field water movement alone is not Internal field water movement alone is not sufficient if the soil ill-drained and highly sufficient if the soil ill-drained and highly organic or applied with organic materialorganic or applied with organic material Mechanical stirring can expel chemicals in soil Mechanical stirring can expel chemicals in soil

formed due to decayformed due to decay

Poor root activity from booting stage and Poor root activity from booting stage and application of N at heading will increase application of N at heading will increase sterilitysterility

Closer Closer vsvs. Wider spacing. Wider spacing

Root distribution

Rectangular, closer 15cm x 10 cm

Square, wider 25cm x 25 cm


Rotary weeding

Rectangular, closer

Square, wider

Root distribution



Complete covering

of soil surface


Rotary weeding

Rectangular, closer

Square, wider

Root distribution




Total root biomass per hill is higher in Total root biomass per hill is higher in wider spacingwider spacing than closer spacing than closer spacing

Total root biomass Total root biomass per unit area is per unit area is higher in closer spacinghigher in closer spacingResults in Results in competitioncompetitionDevelops root matDevelops root matYellowing of leavesYellowing of leavesDiscolorationDiscoloration of the root of the rootAccelerated root decaying processAccelerated root decaying process

Closer Closer vsvs. wider spacing. wider spacing

Canopy coverage is earlier in closer spacingCanopy coverage is earlier in closer spacing Mutual shadingMutual shading Self thinning of secondary and tertiary tillersSelf thinning of secondary and tertiary tillers Decaying roots and decaying tillers accelerates Decaying roots and decaying tillers accelerates

the formation of reduced soilthe formation of reduced soil Leads to poor root activityLeads to poor root activity Reduces the photosynthetic activityReduces the photosynthetic activity Advances Advances leaf senescenceleaf senescence Ends with poor grain fillingEnds with poor grain filling Thus, Thus, sudden dip in the growth curvesudden dip in the growth curve earlier than earlier than

expectedexpected


0

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0 31 41 51 61 71 91 110

Duartion (days)

Bio

mas

s kg

/ha

Closer spacing

Wider spacing

A Model


0

2000

4000

6000

8000

10000

12000

14000

16000

18000

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0 31 41 51 61 71 91 110

Duartion (days)

Bio

mas

s kg

/ha

Closer spacing

Wider spacing

A Model

Expected


A Model

0

2000

4000

6000

8000

10000

12000

14000

16000

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0 23 33 43 53 63 74 84 91

No

Drainage

Effect of drainage

Resembles drainage vs. No drainage

0

2000

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10000

12000

14000

16000

18000

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0 31 41 51 61 71 91 110

Duartion (days)

Bio

mas

s kg

/ha

Closer spacing

Wider spacing

Best Management PracticesBest Management Practices

Different seed rates as per age groups / soilDifferent seed rates as per age groups / soil Seedling age: 21-30 days as per duration/soilSeedling age: 21-30 days as per duration/soil Not more than 2 seedlings per hillNot more than 2 seedlings per hill Line planting and surface planting (2cm) andLine planting and surface planting (2cm) and Integrated NMIntegrated NM

Organic + Inorganic as per soil and seasonOrganic + Inorganic as per soil and season IWM (manual, mechanical, chemical)IWM (manual, mechanical, chemical) Irrigation - 5cm and one day disappearance of Irrigation - 5cm and one day disappearance of

ponded water before irrigation againponded water before irrigation again Need-based pest and disease managementNeed-based pest and disease management

Adoption level of Best ManagementAdoption level of Best Management

Very minimalVery minimalFarms which adopt realize > 8t / haFarms which adopt realize > 8t / haHighest yield attained were by BMPHighest yield attained were by BMP

Reasons for non adoptionReasons for non adoptionFarm-level constraintsFarm-level constraints

Unpredictable monsoon Unpredictable monsoon Uncertainty of canal water availabilityUncertainty of canal water availabilityNon-availability of labor and machineryNon-availability of labor and machinerySmall landholdings unsuitable for Small landholdings unsuitable for

mechanizationmechanization

14 d vs. 24 d seedlings 14 d vs. 24 d seedlings (wet season 2001-02)(wet season 2001-02)

24 D24 D 14 D14 D

Irrigation Irrigation 5cm5cm

Irrigation Irrigation SRISRI



No RotaryNo Rotary RNRN 6.156.15 6.206.20 6.846.84 6.276.27

RN+GLMRN+GLM 6.006.00 6.206.20 5.895.89 5.065.06

RotaryRotary RNRN 6.016.01 6.916.91 6.846.84 6.716.71

RN+GLMRN+GLM 6.346.34 6.356.35 7.617.61 7.237.23

Senthil kumar et al., 2002RN - Recommended nutrients

GLM- Green Leaf Manure 6.25t

14 d vs. 24 d seedlings14 d vs. 24 d seedlings(wet season 2001-02)(wet season 2001-02)

24 D24 D 14 D14 D






RN+GLMRN+GLM 6.006.00 6.206.20 5.895.89 5.065.06


RN+GLMRN+GLM 6.346.34 6.356.35 7.617.61 7.237.23



Direct seeding vs 24 D (Dry season 2002)Direct seeding vs 24 D (Dry season 2002)

24 D24 D Direct seeded Direct seeded






RN+GLMRN+GLM 6.266.26 5.815.81 6.606.60 6.396.39


RN+GLMRN+GLM 6.316.31 6.086.08 6.946.94 6.616.61



Direct seeded with 3-4 seeds then thinned to one

Conventional vs. SRI (100 sites), 2004Conventional vs. SRI (100 sites), 2004

0

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10000

12000

Minimum Maximum Average

Conventional

SRI

Thiyagarajan : TNAU website

Advantages in SRIAdvantages in SRI Higher percent Higher percent filling of grainsfilling of grains in panicle due in panicle due

continued root activitycontinued root activity Higher percent of Higher percent of productive tillersproductive tillers Remains greenRemains green due to unwanted biomass due to unwanted biomass

productionproduction Avoids mutual shadingAvoids mutual shading Saving in N budget in due courseSaving in N budget in due course

Saving of irrigation waterSaving of irrigation water Pests and disease resistancePests and disease resistance Resistance to lodgingResistance to lodging Very much lower seed rateVery much lower seed rate Can minimize yield loss due to dry spells by less Can minimize yield loss due to dry spells by less

roots per unit arearoots per unit area

Impact of irrigation stress Impact of irrigation stress

Wet season Wet season 2006-072006-07

Dry season Dry season 20072007

SRI (SRI (25 x 2525 x 25)) 6.726.72 6.676.67

SRI+ Dry spellsSRI+ Dry spells 5.455.45 5.585.58

Conventional (Conventional (20 x 10; 15 x 1020 x 10; 15 x 10)) 6.476.47 6.156.15

Conventional + Dry Conventional + Dry spellsspells

5.055.05 5.015.01

Sumathi 20082 dry spells ( 20d for wet season and 15 d for dry season) at PI and flowering)

Constraints in SRIConstraints in SRI Handling of young seedlingsHandling of young seedlings

Increasing labour shortageIncreasing labour shortage Unwilling to transplant - more stress to mindUnwilling to transplant - more stress to mind

Unleveled field conditionUnleveled field condition More standing waterMore standing water Disappearance of lines marked (loose soils, sudden Disappearance of lines marked (loose soils, sudden

downpour after marking, etc.)downpour after marking, etc.) Repeated gap fillingRepeated gap filling Weeds have early advantageWeeds have early advantage Troublesome manual rotary usageTroublesome manual rotary usage

Requires varying draught powers for different soilsRequires varying draught powers for different soils Unsuitable soilsUnsuitable soils

Unsuitable seasons / locationsUnsuitable seasons / locations Necessarily in certain areas conventional method need Necessarily in certain areas conventional method need

to be maintained to be maintained

Modification – in SRIModification – in SRI

Based on the difficulties encountered Based on the difficulties encountered for nursery and transplantingfor nursery and transplanting

A modified method is being under A modified method is being under developmentdevelopment

It is SRI It is SRI Direct Planting SystemDirect Planting System (DPS) (DPS)

SRI Direct Planting SystemSRI Direct Planting System

20 to 30 kg/ha of germinated seed is 20 to 30 kg/ha of germinated seed is broadcast after sproutingbroadcast after sprouting

Water is managed well for next 8 daysWater is managed well for next 8 daysAfter 8 -12 days, rotary weedier is After 8 -12 days, rotary weedier is

usedused

Direct Planting System of SRIDirect Planting System of SRI


20 to 30 kg is broadcast after 20 to 30 kg is broadcast after sproutingsprouting

Water is managed well for next 8 daysWater is managed well for next 8 daysFrom 8 -12 days onward, the rotary From 8 -12 days onward, the rotary

weeder is used to control weedsweeder is used to control weedsRotary weeder is used for 2nd time Rotary weeder is used for 2nd time

one week after 1st weeding, but before one week after 1st weeding, but before tilleringtillering


20 to 30 kg is broadcast after sprouting20 to 30 kg is broadcast after sprouting Water is managed well for next 8 daysWater is managed well for next 8 days From 8 -12 days onward, rotary weeder From 8 -12 days onward, rotary weeder

is usedis used Rotary weeder is used for 2nd time a Rotary weeder is used for 2nd time a

week after 1week after 1stst weeding, but before weeding, but before tilleringtillering

Widening the rotary area to thin the rice Widening the rotary area to thin the rice seedlings to single plant or two seedlings to single plant or two


AdvantageAdvantageNo need for nursery and no transplantingNo need for nursery and no transplantingNo transplanting shock to plantsNo transplanting shock to plantsTillering starts at first opportunityTillering starts at first opportunity

ConstraintsConstraintsSuitable only where SRI is practicableSuitable only where SRI is practicableThinning to single seedling during manual Thinning to single seedling during manual

weeding is very essential weeding is very essential

To concludeTo conclude1.1. Potential yield of rice is attainablePotential yield of rice is attainable

By maintaining active root system to maturityBy maintaining active root system to maturity Not necessarily by quantity of rootsNot necessarily by quantity of roots Nor always by excess shoot biomassNor always by excess shoot biomass

2.2. Well-drained soils possess natural ability to Well-drained soils possess natural ability to maintain root healthmaintain root health

But this requires additional nutrients and waterBut this requires additional nutrients and water3.3. Most of the soils require manual / mechanical soil Most of the soils require manual / mechanical soil

stirring to enhance grain yieldstirring to enhance grain yield4.4. Poorly-drained soils / soils with higher organic Poorly-drained soils / soils with higher organic

matter require definite root aerationmatter require definite root aeration

To conclude..To conclude..

5.5. SRI type of cultivation has definite SRI type of cultivation has definite advantages for root healthadvantages for root health

6.6. Like Best Management Practices, SRI Like Best Management Practices, SRI practices are not adopted in fullpractices are not adopted in full

Constraints in SRI may lead to Constraints in SRI may lead to discontinuation in due coursediscontinuation in due course

7.7. SRI may not be recommended to entire SRI may not be recommended to entire rice belt; conventional needs to continuerice belt; conventional needs to continue

8.8. Yet, SRI can revive interest in rice farming Yet, SRI can revive interest in rice farming with modifications to suit local conditionswith modifications to suit local conditions

0893 Conventional Rice vs SRI - Prospects

Technology

Transcript of 0893 Conventional Rice vs SRI - Prospects