Identification of the critical factors of Identification of the critical factors of System of Rice Intensification (SRI) System of Rice Intensification (SRI)

for maximizing Boro rice yield in for maximizing Boro rice yield in Bangladesh Bangladesh

Presented byPresented by

Md. Abu Bakar Siddique SarkerMd. Abu Bakar Siddique SarkerPrincipal Scientific Officer, Agronomy DivisionPrincipal Scientific Officer, Agronomy Division

Bangladesh Rice Research Institute (BRRI)Bangladesh Rice Research Institute (BRRI)Gazipur, BangladeshGazipur, Bangladesh

Significance of this research work Significance of this research work • Rice is the staple food of Bangladeshi people.

• Rice is currently cultivated on 10.61 million hectares, with Rice is currently cultivated on 10.61 million hectares, with production of 34.4 million tons, and average yield of 4.73 t production of 34.4 million tons, and average yield of 4.73 t haha-1-1 (BRRI, 2014). (BRRI, 2014).

• This yield is well below that of other rice-growing countries This yield is well below that of other rice-growing countries such as China, Japan, Korea and Egypt, with yields of 6.8, such as China, Japan, Korea and Egypt, with yields of 6.8, 6.7, 7.5, and 10.10 t ha6.7, 7.5, and 10.10 t ha-1-1, respectively (IRRI, 2015)., respectively (IRRI, 2015).

• By 2025, the total rice area will probably be reduced by 5% or so, while the 21% additional more rice needed by then will have to be produced from less land (Bhuiyan et al., 2002).

• Further, varietal gains in yield potential have been declining.

• Higher rice production will thus have to be achieved mostly through improvements in agronomic management.

The System of Rice Intensification developed in The System of Rice Intensification developed in Madagascar Madagascar is a set of specific crop management is a set of specific crop management practices, some of them counter-intuitive, that practices, some of them counter-intuitive, that are based on certain principles whose are based on certain principles whose application should be adapted to local conditionsapplication should be adapted to local conditions rather than simply adopted as a set package.rather than simply adopted as a set package.– – SRI is thus more like a SRI is thus more like a menumenu than a than a reciperecipe for for raising rice productivity. raising rice productivity.

SRI has the potential to improve rice production without or with less dependence on:

• New rice varieties, • Agrochemical inputs – fertilizers and biocides, or• Large amounts of irrigation water. It can contribute to a healthier natural

environment, with better water quality and soil health

WHAT IS SRI ?WHAT IS SRI ?

• The technique is now being studied and evaluated in many South and Southeast Asian countries by– Scientists, – Extension workers, and – Rice growers.

• SRI is gaining acceptance and use in all of the rice-growing countries of Asia, where 90% of the world's rice is grown.– Its methods are being promoted by governments

in China, India, Indonesia, Cambodia and Vietnam, which together grow 2/3 of the world’s rice.

• Results from many countries of the world give evidence of quite positive results from SRI methods (http://sri.cals.cornell.edu ).– The benefits of SRI management have been seen to

date in 55 countries in Asia, Africa and Latin America.

• SRI methodology in Bangladesh has been reported SRI methodology in Bangladesh has been reported to have a high production potential in the to have a high production potential in the BoroBoro season in comparison with currently season in comparison with currently recommended practices, farmer practices, the recommended practices, farmer practices, the seedling-throwing method, and use of a drum seedling-throwing method, and use of a drum seeder in light-textured soils (Sarker seeder in light-textured soils (Sarker et al.et al. 2007). 2007).

• Some GOs and NGOs in Bangladesh have initiated Some GOs and NGOs in Bangladesh have initiated SRI method on a limited scale in farmer’s fields, SRI method on a limited scale in farmer’s fields, and these trials have showed promising results.and these trials have showed promising results.

• It is seen that SRI can be a low-input, low-cost and It is seen that SRI can be a low-input, low-cost and high-productivity technology for the resource-high-productivity technology for the resource-poor farmers. poor farmers.

• The new techniques of SRI are expected to change The new techniques of SRI are expected to change traditional management practices by showing the traditional management practices by showing the unexploited potentials of rice production in unexploited potentials of rice production in Bangladesh, but more evaluation is still needed.Bangladesh, but more evaluation is still needed.

The basic elements of SRI are: The basic elements of SRI are:

1. Start by transplanting younger seedlings (< 15 d), quickly and carefully, only 1-2 cm deep into soil that is muddy but not flooded;

2. Transplant the seedlings far apart, one per hill, Transplant the seedlings far apart, one per hill, and in a square pattern to facilitate weeding, and in a square pattern to facilitate weeding, reducing plant population mreducing plant population m-2-2 by 80-90%; by 80-90%;

3.3. Keep the soil well-drained, not always flooded, Keep the soil well-drained, not always flooded, maintaining mostly aerobic soil conditions;maintaining mostly aerobic soil conditions;

4.4. Control weed growth with a mechanical weeder Control weed growth with a mechanical weeder that aerates the soil, using early and often; andthat aerates the soil, using early and often; and

5.5. Improve soil structure and functioning by Improve soil structure and functioning by building up soil organic matter with compost or building up soil organic matter with compost or other OM.other OM.

These practices together promote larger, healthier and These practices together promote larger, healthier and longer-lived root systems and more abundant, diverse longer-lived root systems and more abundant, diverse communities of beneficial soil organisms that provide communities of beneficial soil organisms that provide services and protection. services and protection.

THE CRITICAL FACTORS OF SRITHE CRITICAL FACTORS OF SRI

Find out the best Find out the best crop establishment timecrop establishment time and and seedling ageseedling age for effective tiller production and crop for effective tiller production and crop performance in the performance in the BoroBoro season with SRI season with SRI techniques;techniques;

FFind out the best ind out the best water management practiceswater management practices for for crop performance with SRI techniques;crop performance with SRI techniques;

Find out the best Find out the best integrated use of manure and integrated use of manure and fertilizerfertilizer for crop performance with SRI techniques; for crop performance with SRI techniques;

Find out the effect of Find out the effect of soil-stirring practicessoil-stirring practices for best for best crop performance under SRI management; crop performance under SRI management;

Investigate the effects of Investigate the effects of spacingspacing and and seedling-seedling-raising methodraising method for higher performance of Boro rice for higher performance of Boro rice under SRI;under SRI;

Find out and recommend the Find out and recommend the best combinationbest combination of of critical factors for yield maximization of critical factors for yield maximization of BoroBoro crop crop under under SRI.SRI.

The study was undertaken with following The study was undertaken with following objectives:objectives:

The research was carried out at the Bangladesh The research was carried out at the Bangladesh Rice Research Institute research farm at Rice Research Institute research farm at Gazipur, which is:Gazipur, which is:

– Located between 23Located between 23°°59'23'' N latitude and 59'23'' N latitude and 9090°°24'19'' E longitude 24'19'' E longitude

– Mean elevation is 49 ft above sea level Mean elevation is 49 ft above sea level – Agro-ecological region is Madhupur TractAgro-ecological region is Madhupur Tract– Mean annual precipitation is 2039 mmMean annual precipitation is 2039 mm– Mean annual temperature is 25.7Mean annual temperature is 25.7°°C, with a C, with a

mean maximum temperature of 30.4 mean maximum temperature of 30.4°°C, and a C, and a mean minimum temperature of 21.1 mean minimum temperature of 21.1°°CC

– Day length ranging from 10.7 to 13.7 hours. Day length ranging from 10.7 to 13.7 hours.

Location of the experimentsLocation of the experiments

• Ten experiments were conducted over four Ten experiments were conducted over four years’ time to fulfill the above objectives.years’ time to fulfill the above objectives.

• Experiments 1, 2, 3 and 4 were conducted in the Experiments 1, 2, 3 and 4 were conducted in the 1 1stst year ( year (BoroBoro 2007-2008) and were repeated 2007-2008) and were repeated the next year (the next year (BoroBoro 2008-09) as experiments 5, 2008-09) as experiments 5, 6, 7 and 8 for confirmation of the 16, 7 and 8 for confirmation of the 1stst year year results.results.

• Based on evaluation of the 1Based on evaluation of the 1stst and 2 and 2ndnd year year results, experiment 9 was designed for the 3results, experiment 9 was designed for the 3rdrd year (year (BoroBoro 2009-10) in which the best practice 2009-10) in which the best practice performances were further evaluated against performances were further evaluated against each other.each other.

• Then in the 4Then in the 4thth year (2010-11), experiment 10 year (2010-11), experiment 10 was undertaken for a controlled comparison, was undertaken for a controlled comparison, testing the SRI practices that had shown testing the SRI practices that had shown themselves to be the best in previous trials themselves to be the best in previous trials against the rice production system currently against the rice production system currently being recommended for being recommended for BoroBoro season by BRRI. season by BRRI.

Methodology followed

• Results of Experiments 1 and 5Results of Experiments 1 and 5: Grain yield under SRI at : Grain yield under SRI at early transplantation (November 15) and late early transplantation (November 15) and late transplantation (after January 15) did not perform so well, transplantation (after January 15) did not perform so well, whereas transplanting between November 30 to December whereas transplanting between November 30 to December 15 produced higher yield. 15 produced higher yield.

• When germinated seed was transplanted, grain yield was When germinated seed was transplanted, grain yield was lower, while it was increased from us of 8-day and 12-day lower, while it was increased from us of 8-day and 12-day old seedlings. No yield increase was seen with 16-day old old seedlings. No yield increase was seen with 16-day old seedlings. seedlings.

Conclusion:Conclusion: Transplanting under SRI should be done Transplanting under SRI should be done between December 01 to December 15 and with 12-day between December 01 to December 15 and with 12-day old seedlings. old seedlings.

Pictures of different stages of 1st experimentPictures of different stages of 1st experiment

Active tillering stageActive tillering stage Panicle-initiating stagePanicle-initiating stage

Grain-filling stageGrain-filling stage Ripening stageRipening stage

Factor A: Water managementFactor A: Water management Factor B: Soil stirringFactor B: Soil stirringII11 = Conventional flooding = Conventional flooding SS11 = 1 stirring at 20 DAT = 1 stirring at 20 DATII22 = Shallow AWD irrigation at 3 days = Shallow AWD irrigation at 3 days SS22 = 2 stirrings at 20 and 35 = 2 stirrings at 20 and 35

DATDATII33 = Shallow AWD irrigation at 5 days = Shallow AWD irrigation at 5 days SS33 = 3 stirrings at 20, 35 and 45 = 3 stirrings at 20, 35 and 45

DATDATII44 = Shallow AWD irrigation at 7 days = Shallow AWD irrigation at 7 days SS44 = Weekly stirrings after 15 = Weekly stirrings after 15

DATDATII55, I, I66 = Deeper irrigation when water table goes below 15 or 25 cm (measured = Deeper irrigation when water table goes below 15 or 25 cm (measured

by pipe)by pipe)

Results of Experiments 2 and 6Results of Experiments 2 and 6: : Higher grain yield was achieved under Irrigation IHigher grain yield was achieved under Irrigation I22 (water at (water at

3-day intervals) compared to other tested water 3-day intervals) compared to other tested water management practices. Similarly stirring Smanagement practices. Similarly stirring S33 (three (three stirrings) gave higher grain yield.stirrings) gave higher grain yield.

Results of Experiments 3 and 7Results of Experiments 3 and 7::Higher grain yield was obtained with fertilizer/manure Higher grain yield was obtained with fertilizer/manure management treatments Nmanagement treatments N6 6 and Nand N77 (100% rec. inorganic + 5 (100% rec. inorganic + 5 or 10 t haor 10 t ha-1-1 manure). Stirring S manure). Stirring S22 (stirrings at (stirrings at 15, 30 and 45 15, 30 and 45 DAT) DAT) gave the best grain yield.gave the best grain yield.To achieve maximum grain yield under SRI, fertilizer and To achieve maximum grain yield under SRI, fertilizer and manure management either Nmanure management either N6 6 or Nor N7 7 may used with Stirring Smay used with Stirring S22 management.management.

Results of Experiments 4 and 8: Higher grain yield was observed in spacings S5 (30 x25 cm) and S6 (30x30 cm) together with seedling-raising methods M2 and M3 (10d seedlings raised in compost or normal-soil nursery beds).

Pictures of different stages of experiments 4 and 8

Seedling-raising methodsSeedling-raising methods Maximum tillering stageMaximum tillering stage

Maturity stageMaturity stage

Experiment 9On the basis of 1On the basis of 1stst and 2 and 2ndnd year information, experiment 9 evaluated: year information, experiment 9 evaluated:Factor A: Spacing (2 treatments)Factor A: Spacing (2 treatments) SS11 = 25 x 15 cm = 25 x 15 cm SS22 = 30 x 30 cm = 30 x 30 cmFactor B: Water management methods (2 treatments)Factor B: Water management methods (2 treatments)

II11 = 5-7 cm depth of water was added to field, followed by further irrigation = 5-7 cm depth of water was added to field, followed by further irrigation at 3 days after disappearance. This was continued from 15 DAT to PI at 3 days after disappearance. This was continued from 15 DAT to PI stage, then 5-7 cm standing water was kept up to hard dough stagestage, then 5-7 cm standing water was kept up to hard dough stage

II22 = 2-3 cm depth of water was added to field during irrigation just for = 2-3 cm depth of water was added to field during irrigation just for soaking the soil; then further irrigation was added at 3 days after soaking the soil; then further irrigation was added at 3 days after disappearing. This was continued from 15 DAT to PI stage; then 5-7 cm disappearing. This was continued from 15 DAT to PI stage; then 5-7 cm standing water was kept up to hard dough stagestanding water was kept up to hard dough stage

Factor C: Fertilizer and manure management (2 treatments)Factor C: Fertilizer and manure management (2 treatments)NN11 = 100% of the recommended inorganic fertilizer = 100% of the recommended inorganic fertilizer NN22 = 10 t/ha of manure + 100% of the recommended inorganic fertilizer = 10 t/ha of manure + 100% of the recommended inorganic fertilizer

Factor D: Soil stirring (2 treatments)Factor D: Soil stirring (2 treatments)M1 = No soil stirring M1 = No soil stirring M2 = Stirring at 15 DAT, 30 DAT, and 45 DATM2 = Stirring at 15 DAT, 30 DAT, and 45 DAT

Spacing Spacing (S)(S)

Seedling Seedling (M)(M)

Irrigation Irrigation (I)(I)

Nutrients (N)Nutrients (N) MeanMean DifferenceDifferenceNN11 NN22

SS11 MM11 II11 9.83 a9.83 a 8.57 b8.57 b 9.209.20 1.25 **1.25 **

SS11 MM11 II22 8.65 b8.65 b 7.65 c7.65 c 8.158.15 1.00 **1.00 **

SS11 MM22 II11 9.65 a9.65 a 8.62 b8.62 b 9.149.14 1.03**1.03**

SS11 MM22 II22 8.78 b8.78 b 7.29 c7.29 c 8.048.04 1.50**1.50**

SS22 MM11 II11 9.62 a9.62 a 8.38 b8.38 b 9.009.00 1.24**1.24**

SS22 MM11 II22 9.48 a9.48 a 8.86 b8.86 b 8.978.97 1.02**1.02**

SS22 MM22 II11 9.58 a9.58 a 8.66 b8.66 b 9.129.12 0.91**0.91**

SS22 MM22 II22 8.79 b8.79 b 7.16 c7.16 c 7.987.98 1.63**1.63**

MeanMean 9.309.30 8.108.10 8.708.70 1.201.20

Interaction effects of selected factors of SRI practice on the grain yield (t ha-1) of BRRI dhan29 in Boro season, 2009-10

** 1% significance

Conclusion: Conclusion: Highest yield performance was obtained by Highest yield performance was obtained by combination ofcombination of S1 M1 N1 I1S1 M1 N1 I1 treatments treatments (9.83 t/ha)(9.83 t/ha) followed followed by by S1 M2 N1 I1S1 M2 N1 I1 (9.65 t/ha),(9.65 t/ha), thenthen S2 M1 N1 I1 S2 M1 N1 I1 (9.62 t/ha)(9.62 t/ha)

Results of 9Results of 9thth experiment experimentThe highest grain yield (9.83 t haThe highest grain yield (9.83 t ha-1-1) was recorded ) was recorded when:when:

12-day-old seedlings raised in compost bed (M12-day-old seedlings raised in compost bed (M11) )

werewere

Transplanted with 30 × 25-cm spacing (STransplanted with 30 × 25-cm spacing (S11),),

Maintaining 2-3 cm depth of irrigation from 15 Maintaining 2-3 cm depth of irrigation from 15

DAT, followed by further irrigations at 3-day DAT, followed by further irrigations at 3-day

intervals after disappearance during vegetative intervals after disappearance during vegetative

growth period (Igrowth period (I11) )

Application of 10 t haApplication of 10 t ha-1-1 of manure + 100% of the of manure + 100% of the

recommended inorganic fertilizer treatment (Nrecommended inorganic fertilizer treatment (N11) ) Altogether interacting as treatment SAltogether interacting as treatment S11MM11II11NN11

Experiment 10Experiment 10This experiment was based on the best This experiment was based on the best performances for different SRI practices from the performances for different SRI practices from the preceding 3 years of evaluation (experiments 1 preceding 3 years of evaluation (experiments 1 through 9), being designed as follows:through 9), being designed as follows:

MAIN PLOTS : Stirring (M) 2 x Irrigation (I) 2 = 4 levelsMAIN PLOTS : Stirring (M) 2 x Irrigation (I) 2 = 4 levels

SUB-PLOTS: Spacing (S) 2 x Seedling Age (A) 2 = 4 levelsSUB-PLOTS: Spacing (S) 2 x Seedling Age (A) 2 = 4 levels

SUB-SUB-PLOTS: Manure & Fertilizer (N) = 2 levelsSUB-SUB-PLOTS: Manure & Fertilizer (N) = 2 levels

Treatments = 4 x 4 x 2 = 32 x 3 replications = 96 Treatments = 4 x 4 x 2 = 32 x 3 replications = 96 total total

Results of Experiment 10Results of Experiment 10

** = significant at 1% level, * = significant at 5% level, ns = not significantIn a column under each A, means followed by a common letters are not significantly different at the 5% level by DMRT.

Sub-plotsSub-plots (Spacing × (Spacing ×

Seedling age)Seedling age)

Main plotsMain plots(Irrigation × (Irrigation ×

Stirring )Stirring )

Sub-sub plots (Nutrient Sub-sub plots (Nutrient management)management)

NN11 NN22 DifferencesDifferences

AA11= M= M11II115.27 c5.27 c5.62 b5.62 b6.04 ab6.04 ab6.65 a6.65 a

6.00 b6.00 b6.28 b6.28 b6.82 a6.82 a7.08 a7.08 a

5.54 c5.54 c6.39 b6.39 b6.25 bc6.25 bc7.72 a7.72 a

5.87 c5.87 c7.03 b7.03 b6.63 b6.63 b7.87 a7.87 a

5.85 b5.85 b6.72 b6.72 b6.74 b6.74 b7.39 a7.39 a

6.57 c6.57 c6.93 bc6.93 bc7.65 ab7.65 ab7.79 a7.79 a

6.26 c6.26 c7.48 b7.48 b7.83 b7.83 b9.43 a9.43 a

6.62 c6.62 c7.84 b7.84 b7.97 b7.97 b10.17 a10.17 a

-0.58 *-0.58 *-0.81 *-0.81 *-0.70 *-0.70 *-0.74 *-0.74 *

-0.57 *-0.57 *-0.65 *-0.65 *-0. 83 *-0. 83 *-0.71 *-0.71 *

-0.72 *-0.72 *-1.08 **-1.08 **-1.58 **-1.58 **-1.71 **-1.71 **

-0. 75 *-0. 75 *-0.81 *-0.81 *-1.35 **-1.35 **-2.30 **-2.30 **

BB11= S= S11AA11

BB22= S= S11AA22

BB33= S= S22AA11

BB44= S= S22AA22

MM11II11

MM11II11

MM11II11

MM11II11

AA22= M= M11II22

BB11= S= S11AA11

BB22= S= S11AA22

BB33= S= S22AA11

BB44= S= S22AA22

MM11II22

MM11II22

MM11II22

MM11II22

AA33= M= M22II11

BB11= S= S11AA11

BB22= S= S11AA22

BB33= S= S22AA11

BB44= S= S22AA22

MM22II11

MM22II11

MM22II11

MM22II11

AA44= M= M22II22

BB11= S= S11AA11

BB22= S= S11AA22

BB33= S= S22AA11

BB44= S= S22AA22

MM22II22

MM22II22

MM22II22

MM22II22

Conclusions:Conclusions:It was observed that wider spacing (SIt was observed that wider spacing (S22), ), SRI irrigation methods (ISRI irrigation methods (I22), younger ), younger seedling age (Aseedling age (A22), three stirrings (M), three stirrings (M22), ), and 10 t haand 10 t ha-1-1 compost with compost with recommended inorganic fertilizers (Nrecommended inorganic fertilizers (N22) -- ) -- as interacting treatments -- produced as interacting treatments -- produced higher grain yield than presently higher grain yield than presently recommended spacing (Srecommended spacing (S11), irrigation ), irrigation method (Imethod (I22), seedling are (A), seedling are (A11) and no ) and no stirring (Mstirring (M11).).

The highest grain yield (10.17 t haThe highest grain yield (10.17 t ha-1-1) was ) was obtained from the treatment Sobtained from the treatment S22AA22MM22II22NN2 2

where all the selected best SRI practices where all the selected best SRI practices were collectively interacting.were collectively interacting.

Conclusions and Recommendations:

Based on the study, it may be concluded that integration of the best-performing SRI cultural factors may be recommended for maximization of Boro rice yield for a long-duration variety like BRRI Dhan29 in Bangladesh. The following best-performing SRI cultural factors are to be considered:

1.Transplanting should be done during the period from 30 November to 15 December. 2.Younger seedlings of 12-days age, preferably raised in compost bed, should be used for transplanting.

Conclusions and Recommendations:3.Transplanting may be done with wider spacing of 30 cm × 25 cm than at present. 4.SRI irrigation management should be followed. 5.Soil stirrings at 15, 30 and 45 DAT may enhance the productivity of irrigated rice. 6.BRRI-recommended fertilizer applications are not enough for maximizing grain yield with SRI techniques. Integrated use of fertilizer plus manure at 10 t ha-1 using the recommended rate for inorganic fertilizers would enhance rice crop productivity in Boro season.

Future Research However, further research should be conducted to address the following important issues:

• Research shall be done with the selected SRI cultural factors for medium- and short-duration MVs and hybrid rice varieties in the Boro season to assess how to further optimize grain yield.

• Research on selected SRI cultural factors on different problem soils, especially light-textured soils and saline soil, may be continued.

• Research on determining cost-effectiveness for the weed control methods under SRI practices for yield maximization should be undertaken.

Acknowledgements

• Professor Dr. Najrul Islam • Professor Dr. M. A. Samad • BRRI Authority• Department of Agronomy, BAU,

Mymenshing• Agronomy Division, BRRI, Gazipur