Conventional Rice vs Conventional Rice vs SRI SRI - - Prospects Prospects S.Ramasamy Professor (Agronomy) Tamil Nadu Agricultural University, Coimbatore, INDIA 641 003 [email protected]
Sep 10, 2014
Conventional Rice vs SRI Conventional Rice vs SRI - - ProspectsProspects
S.RamasamyProfessor (Agronomy)
Tamil Nadu Agricultural University,
Coimbatore, INDIA 641 003
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
Farmers’ way of rice cultivationFarmers’ way of rice cultivation
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
Farmers’ way of rice cultivationFarmers’ way of rice cultivation
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
2000
4000
6000
8000
10000
12000
14000
16000
18000
20000
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 activityRoot 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 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 activityRoot activity
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
Closer Closer vsvs. Wider spacing. Wider spacing
Rotary weeding
Rectangular, closer
Square, wider
Root distribution
Rectangular, closer 15cm x 10 cm
Square, wider 25cm x 25 cm
Complete covering
of soil surface
Closer Closer vsvs. Wider spacing. Wider spacing
Rotary weeding
Rectangular, closer
Square, wider
Root distribution
Rectangular, closer 15cm x 10 cm
Square, wider 25cm x 25 cm
Closer Closer vsvs. Wider spacing. Wider spacing
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
Closer Closer vsvs. wider spacing. wider spacing
0
2000
4000
6000
8000
10000
12000
14000
16000
18000
20000
0 31 41 51 61 71 91 110
Duartion (days)
Bio
mas
s kg
/ha
Closer spacing
Wider spacing
A Model
Closer Closer vsvs. wider spacing. wider spacing
0
2000
4000
6000
8000
10000
12000
14000
16000
18000
20000
0 31 41 51 61 71 91 110
Duartion (days)
Bio
mas
s kg
/ha
Closer spacing
Wider spacing
A Model
Expected
Closer Closer vsvs. wider spacing. wider spacing
A Model
0
2000
4000
6000
8000
10000
12000
14000
16000
18000
20000
0 23 33 43 53 63 74 84 91
No
Drainage
Effect of drainage
Resembles drainage vs. No drainage
0
2000
4000
6000
8000
10000
12000
14000
16000
18000
20000
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
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
Irrigation Irrigation 5cm5cm
Irrigation Irrigation SRISRI
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
Direct seeding vs 24 D (Dry season 2002)Direct seeding vs 24 D (Dry season 2002)
24 D24 D Direct seeded Direct seeded
Irrigation Irrigation 5cm5cm
Irrigation Irrigation SRISRI
Irrigation Irrigation 5cm5cm
Irrigation Irrigation SRISRI
No RotaryNo Rotary RNRN 6.016.01 5.695.69 6.686.68 6.376.37
RN+GLMRN+GLM 6.266.26 5.815.81 6.606.60 6.396.39
RotaryRotary RNRN 6.246.24 6.016.01 6.896.89 6.406.40
RN+GLMRN+GLM 6.316.31 6.086.08 6.946.94 6.616.61
Senthil kumar et al., 2002RN - Recommended nutrients
GLM- Green Leaf Manure 6.25t
Direct seeded with 3-4 seeds then thinned to one
Conventional vs. SRI (100 sites), 2004Conventional vs. SRI (100 sites), 2004
0
2000
4000
6000
8000
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
Direct Planting System of SRIDirect Planting System of SRI
Direct Planting System of SRIDirect Planting System of SRI
Direct Planting System of SRIDirect Planting System of SRI
Direct Planting System of SRIDirect Planting System of SRI
Direct Planting System of SRIDirect Planting System of SRI
Direct Planting System of SRIDirect Planting System of SRI
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
Direct Planting System of SRIDirect Planting System of SRI
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
Direct Planting System of SRIDirect Planting System of SRI
Direct Planting System of SRIDirect Planting System of SRI
Direct Planting System of SRIDirect Planting System of SRI
Direct Planting System of SRIDirect Planting System of SRI
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