0893 Conventional Rice vs SRI - Prospects

3,618 views

Published on

Presenter: S.Ramasamy
Tamil Nadu Agricultural University, Coimbatore

Published in: Technology, Business
0 Comments
1 Like
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total views
3,618
On SlideShare
0
From Embeds
0
Number of Embeds
11
Actions
Shares
0
Downloads
118
Comments
0
Likes
1
Embeds 0
No embeds

No notes for slide

0893 Conventional Rice vs SRI - Prospects

  1. 1. Conventional Rice vs SRI - Prospects S.Ramasamy Professor (Agronomy) Tamil Nadu Agricultural University, Coimbatore, INDIA 641 003 [email_address] SR
  2. 2. Presenting on.. <ul><li>Rice cultivation in India and Tamil Nadu </li></ul><ul><li>Farmers’ way of rice cultivation </li></ul><ul><li>Potential yield </li></ul><ul><li>Root activity and yield </li></ul><ul><li>Best Management Practices for rice </li></ul><ul><li>SRI vs. conventional practice </li></ul><ul><ul><li>Experimental yield levels </li></ul></ul><ul><ul><li>Advantages of SRI </li></ul></ul><ul><ul><li>Constraints in SRI </li></ul></ul><ul><ul><li>Modifications in SRI </li></ul></ul><ul><ul><li>A modified SRI – DPS </li></ul></ul><ul><li>Conclusion </li></ul>SR
  3. 3. Rice cultivation in India <ul><li>40 + million ha with average yield of 2t ha </li></ul><ul><li>Variety of crop establishments </li></ul><ul><ul><li>Lowland </li></ul></ul><ul><ul><ul><li>Transplanted – good yield </li></ul></ul></ul><ul><ul><ul><li>Direct wet-seeded – weed menace </li></ul></ul></ul><ul><ul><ul><li>Dry-seeded and rainfed </li></ul></ul></ul><ul><ul><li>Upland – soil and nutrient losses, poor yield </li></ul></ul><ul><li>Lowland rice - major areas </li></ul><ul><ul><li>Punjab - 3.3 t/ha </li></ul></ul><ul><ul><li>Tamil Nadu – 3.2 t/ha </li></ul></ul><ul><ul><li>AP and WB with large areas under wet ecosystem </li></ul></ul>SR
  4. 4. Rice scenario - in the state of TN <ul><li>2.0 m ha </li></ul><ul><li>Cultivation throughout the year </li></ul><ul><ul><li>Irrigated and rainfed </li></ul></ul><ul><ul><li>Single rice season: August – Dec, Jan </li></ul></ul><ul><ul><ul><li>Major area </li></ul></ul></ul><ul><ul><li>Double rice season irrigated </li></ul></ul><ul><ul><ul><li>June – Sept,; again Oct- Feb </li></ul></ul></ul><ul><ul><ul><li>June – Sept,; again Dec- March </li></ul></ul></ul><ul><ul><li>June- Sept.: Dry season </li></ul></ul><ul><ul><li>Aug- Jan: Wet season </li></ul></ul>SR
  5. 5. Rice scenario - in the state of TN.. <ul><li>Wet season </li></ul><ul><ul><li>Major area (80%) </li></ul></ul><ul><ul><li>Medium and long-duration rice </li></ul></ul><ul><ul><li>Higher biomass but poor HI </li></ul></ul><ul><li>Dry season </li></ul><ul><ul><li>Around 20% area </li></ul></ul><ul><ul><li>Short-duration </li></ul></ul><ul><ul><li>Higher yield than wet season </li></ul></ul><ul><ul><li>Higher HI </li></ul></ul>SR
  6. 6. Farmers’ way of rice cultivation <ul><li>High seed rate and thick nursery </li></ul><ul><li>More than 30-day-old seedlings </li></ul><ul><li>Poor field leveling </li></ul><ul><li>Random planting </li></ul>SR
  7. 7. Farmers way of rice cultivation <ul><li>High seed rate and thick nursery </li></ul><ul><li>More than 30 days old seedlings </li></ul><ul><li>Poor field leveling </li></ul><ul><li>Random planting </li></ul>SR
  8. 8. Farmers’ way of rice cultivation. <ul><li>Clump of seedlings per hill </li></ul><ul><li>Deep planting </li></ul>SR
  9. 9. Farmers’ way of rice cultivation.. <ul><li>Merits </li></ul><ul><ul><li>Plant the entire area in short period </li></ul></ul><ul><ul><li>No land left fallow for want of seedlings </li></ul></ul><ul><ul><li>Gap filling is avoided </li></ul></ul><ul><ul><li>Weeds are managed with less effort </li></ul></ul><ul><ul><li>Risk of failure is minimum </li></ul></ul>SR
  10. 10. Farmers’ way of rice cultivation… <ul><li>De-merits </li></ul><ul><ul><li>Uneven plant stand </li></ul></ul><ul><ul><li>Mechanical weeding is not possible </li></ul></ul><ul><ul><li>Irrigation regime varies within the field </li></ul></ul><ul><ul><li>Poor nutrient management </li></ul></ul><ul><ul><li>Risk of pests and disease out break </li></ul></ul><ul><ul><li>Poor harvest index </li></ul></ul>SR
  11. 11. Farmers’ way of rice cultivation <ul><li>Higher yield obtained by farmers </li></ul><ul><ul><li>Maximum yield competition </li></ul></ul><ul><ul><ul><li>Increased from 12 t /ha in early 80s to > 20 t/ha in 1990s </li></ul></ul></ul><ul><ul><ul><li>Higher yields reported were in: </li></ul></ul></ul><ul><ul><ul><ul><li>Wet season </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Higher green manures </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Not from the traditional delta </li></ul></ul></ul></ul><ul><ul><ul><ul><li>But not repeated </li></ul></ul></ul></ul>SR
  12. 12. Farmers’ way of rice cultivation <ul><li>Higher yields obtained by farmers were not repeated once… </li></ul><ul><ul><li>Reasons remain fuzzy!!! </li></ul></ul><ul><ul><li>Could be that proper soil and water management prevailed in that period </li></ul></ul><ul><ul><li>In drought /dry season get better yield </li></ul></ul><ul><ul><li>There are marked differences between dry and wet seasons </li></ul></ul>SR
  13. 13. Dry season vs . Wet season Dry season Wet season Period (days) Jun- Sep Aug, Sep - Dec, Jan Duration 105 135 Mean Temp ° C 30+ 25+ Solar radiation 450 cal 450 cal Total biomass t/ha 13-17 16-18 Grain yield – State 3.3 2.3 Grain yield – Expt 6-8 5-7 Ratio: PT / TT High Low % grains/panicle High Low Root color White to brown Brown to black Root activity Fairly good After PI sharply falling Probable reason Less standing water Continuous inundation
  14. 14. Potential yield is achievable.. <ul><li>When all the resources are available freely </li></ul><ul><ul><li>Root activity decides the yield level </li></ul></ul><ul><li>It is not the total shoot biomass before heading that determined yield so much as the photosynthesis (> 60 %) and the translocation (> 30 %) after heading </li></ul><ul><li>To maintain photosynthesis until the final spikelets are filled completely, roots should be active , irrespective of quantity of roots </li></ul>SR
  15. 15. Root activity <ul><li>Root activity remains fairly good when internal field drainage does exist </li></ul>SR
  16. 16. Root activity and total biomass SR Ramasamy et al 1997
  17. 17. Root activity and root color SR Ramasamy et al 1997 No drainage With Drainage
  18. 18. Effect of drainage on grain yield SR Ramasamy et al 1997 No Drainage With Drainage
  19. 19. Root activity <ul><li>Root activity remains fairly good when internal field drainage does exist </li></ul><ul><li>Internal field water movement alone is not sufficient if the soil is ill-drained and highly organic or applied with organic material </li></ul>SR
  20. 20. Root activity.. <ul><li>Root activity remains fairly good when internal field drainage does exist </li></ul><ul><li>Internal field water movement alone is not sufficient if the soil ill-drained and highly organic or applied with organic material </li></ul><ul><ul><li>Mechanical stirring can expel out chemicals formed due to decay </li></ul></ul>SR
  21. 21. Root activity <ul><li>Root activity remains fairly good when internal field drainage does exist </li></ul><ul><li>Internal field water movement alone is not sufficient if the soil ill-drained and highly organic or applied with organic material </li></ul><ul><ul><li>Mechanical stirring can expel chemicals in soil formed due to decay </li></ul></ul><ul><li>Poor root activity from booting stage and application of N at heading will increase sterility </li></ul>SR
  22. 22. Closer vs . Wider spacing SR Root distribution Rectangular, closer 15cm x 10 cm Square, wider 25cm x 25 cm
  23. 23. Closer vs . Wider spacing SR 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
  24. 24. Closer vs . Wider spacing SR Rotary weeding Rectangular, closer Square, wider Root distribution Rectangular, closer 15cm x 10 cm Square, wider 25cm x 25 cm
  25. 25. Closer vs . Wider spacing <ul><li>Total root biomass per hill is higher in wider spacing than closer spacing </li></ul><ul><li>Total root biomass per unit area is higher in closer spacing </li></ul><ul><ul><li>Results in competition </li></ul></ul><ul><ul><li>Develops root mat </li></ul></ul><ul><ul><li>Yellowing of leaves </li></ul></ul><ul><ul><li>Discoloration of the root </li></ul></ul><ul><ul><li>Accelerated root decaying process </li></ul></ul>SR
  26. 26. Closer vs . wider spacing <ul><li>Canopy coverage is earlier in closer spacing </li></ul><ul><ul><li>Mutual shading </li></ul></ul><ul><ul><li>Self thinning of secondary and tertiary tillers </li></ul></ul><ul><ul><li>Decaying roots and decaying tillers accelerates the formation of reduced soil </li></ul></ul><ul><ul><li>Leads to poor root activity </li></ul></ul><ul><ul><li>Reduces the photosynthetic activity </li></ul></ul><ul><ul><li>Advances leaf senescence </li></ul></ul><ul><ul><li>Ends with poor grain filling </li></ul></ul><ul><ul><li>Thus, sudden dip in the growth curve earlier than expected </li></ul></ul>SR
  27. 27. Closer vs . wider spacing SR A Model
  28. 28. Closer vs . wider spacing SR A Model Expected
  29. 29. Closer vs . wider spacing SR A Model Effect of drainage Resembles drainage vs. No drainage
  30. 30. Best Management Practices <ul><li>Different seed rates as per age groups / soil </li></ul><ul><li>Seedling age: 21-30 days as per duration/soil </li></ul><ul><li>Not more than 2 seedlings per hill </li></ul><ul><li>Line planting and surface planting (2cm) and </li></ul><ul><li>Integrated NM </li></ul><ul><ul><li>Organic + Inorganic as per soil and season </li></ul></ul><ul><li>IWM (manual, mechanical, chemical) </li></ul><ul><li>Irrigation - 5cm and one day disappearance of ponded water before irrigation again </li></ul><ul><li>Need-based pest and disease management </li></ul>SR
  31. 31. Adoption level of Best Management <ul><li>Very minimal </li></ul><ul><ul><li>Farms which adopt realize > 8t / ha </li></ul></ul><ul><ul><li>Highest yield attained were by BMP </li></ul></ul><ul><li>Reasons for non adoption </li></ul><ul><ul><li>Farm-level constraints </li></ul></ul><ul><ul><ul><li>Unpredictable monsoon </li></ul></ul></ul><ul><ul><ul><li>Uncertainty of canal water availability </li></ul></ul></ul><ul><ul><ul><li>Non-availability of labor and machinery </li></ul></ul></ul><ul><ul><ul><li>Small landholdings unsuitable for mechanization </li></ul></ul></ul>SR
  32. 32. 14 d vs. 24 d seedlings (wet season 2001-02) Senthil kumar et al., 2002 RN - Recommended nutrients GLM- Green Leaf Manure 6.25t 24 D 14 D Irrigation 5cm Irrigation SRI Irrigation 5cm Irrigation SRI No Rotary RN 6.15 6.20 6.84 6.27 RN+GLM 6.00 6.20 5.89 5.06 Rotary RN 6.01 6.91 6.84 6.71 RN+GLM 6.34 6.35 7.61 7.23
  33. 33. 14 d vs. 24 d seedlings (wet season 2001-02) Senthil kumar et al., 2002 RN - Recommended nutrients GLM- Green Leaf Manure 6.25t 24 D 14 D Irrigation 5cm Irrigation SRI Irrigation 5cm Irrigation SRI No Rotary RN 6.15 6.20 6.84 6.27 RN+GLM 6.00 6.20 5.89 5.06 Rotary RN 6.01 6.91 6.84 6.71 RN+GLM 6.34 6.35 7.61 7.23
  34. 34. Direct seeding vs 24 D (Dry season 2002) Senthil kumar et al., 2002 RN - Recommended nutrients GLM- Green Leaf Manure 6.25t Direct seeded with 3-4 seeds then thinned to one 24 D Direct seeded Irrigation 5cm Irrigation SRI Irrigation 5cm Irrigation SRI No Rotary RN 6.01 5.69 6.68 6.37 RN+GLM 6.26 5.81 6.60 6.39 Rotary RN 6.24 6.01 6.89 6.40 RN+GLM 6.31 6.08 6.94 6.61
  35. 35. Conventional vs. SRI (100 sites), 2004 Thiyagarajan : TNAU website
  36. 36. Advantages in SRI <ul><li>Higher percent filling of grains in panicle due continued root activity </li></ul><ul><li>Higher percent of productive tillers </li></ul><ul><li>Remains green due to unwanted biomass production </li></ul><ul><ul><li>Avoids mutual shading </li></ul></ul><ul><ul><li>Saving in N budget in due course </li></ul></ul><ul><li>Saving of irrigation water </li></ul><ul><li>Pests and disease resistance </li></ul><ul><li>Resistance to lodging </li></ul><ul><li>Very much lower seed rate </li></ul><ul><li>Can minimize yield loss due to dry spells by less roots per unit area </li></ul>SR
  37. 37. Impact of irrigation stress Sumathi 2008 2 dry spells ( 20d for wet season and 15 d for dry season) at PI and flowering) Wet season 2006-07 Dry season 2007 SRI ( 25 x 25 ) 6.72 6.67 SRI+ Dry spells 5.45 5.58 Conventional ( 20 x 10; 15 x 10 ) 6.47 6.15 Conventional + Dry spells 5.05 5.01
  38. 38. Constraints in SRI <ul><li>Handling of young seedlings </li></ul><ul><ul><li>Increasing labour shortage </li></ul></ul><ul><ul><li>Unwilling to transplant - more stress to mind </li></ul></ul><ul><li>Unleveled field condition </li></ul><ul><ul><li>More standing water </li></ul></ul><ul><ul><li>Disappearance of lines marked (loose soils, sudden downpour after marking, etc.) </li></ul></ul><ul><li>Repeated gap filling </li></ul><ul><li>Weeds have early advantage </li></ul><ul><li>Troublesome manual rotary usage </li></ul><ul><ul><li>Requires varying draught powers for different soils </li></ul></ul><ul><ul><li>Unsuitable soils </li></ul></ul><ul><li>Unsuitable seasons / locations </li></ul><ul><ul><li>Necessarily in certain areas conventional method need to be maintained </li></ul></ul>SR
  39. 39. Modification – in SRI <ul><li>Based on the difficulties encountered for nursery and transplanting </li></ul><ul><li>A modified method is being under development </li></ul><ul><li>It is SRI Direct Planting System (DPS) </li></ul>SR
  40. 40. SRI Direct Planting System <ul><li>20 to 30 kg/ha of germinated seed is broadcast after sprouting </li></ul><ul><li>Water is managed well for next 8 days </li></ul><ul><li>After 8 -12 days, rotary weedier is used </li></ul>SR
  41. 41. Direct Planting System of SRI SR Before I rotary weeding 10 DAS
  42. 42. Direct Planting System of SRI SR
  43. 43. Direct Planting System of SRI SR
  44. 44. Direct Planting System of SRI SR
  45. 45. Direct Planting System of SRI SR
  46. 46. Direct Planting System of SRI SR Crisscross direction
  47. 47. Direct Planting System of SRI SR
  48. 48. Direct Planting System of SRI <ul><li>20 to 30 kg is broadcast after sprouting </li></ul><ul><li>Water is managed well for next 8 days </li></ul><ul><li>From 8 -12 days onward, the rotary weeder is used to control weeds </li></ul><ul><li>Rotary weeder is used for 2nd time one week after 1st weeding, but before tillering </li></ul>SR
  49. 49. Direct Planting System of SRI <ul><li>20 to 30 kg is broadcast after sprouting </li></ul><ul><li>Water is managed well for next 8 days </li></ul><ul><li>From 8 -12 days onward, rotary weeder is used </li></ul><ul><li>Rotary weeder is used for 2nd time a week after 1 st weeding, but before tillering </li></ul><ul><li>Widening the rotary area to thin the rice seedlings to single plant or two </li></ul>SR
  50. 50. Direct Planting System of SRI SR After 2nd rotary weeding and thinning
  51. 51. Direct Planting System of SRI SR Tillering
  52. 52. Direct Planting System of SRI SR Max. Tillering
  53. 53. Direct Planting System of SRI <ul><li>Advantage </li></ul><ul><ul><li>No need for nursery and no transplanting </li></ul></ul><ul><ul><li>No transplanting shock to plants </li></ul></ul><ul><ul><li>Tillering starts at first opportunity </li></ul></ul><ul><li>Constraints </li></ul><ul><ul><li>Suitable only where SRI is practicable </li></ul></ul><ul><ul><li>Thinning to single seedling during manual weeding is very essential </li></ul></ul>SR
  54. 54. To conclude <ul><li>Potential yield of rice is attainable </li></ul><ul><ul><li>By maintaining active root system to maturity </li></ul></ul><ul><ul><li>Not necessarily by quantity of roots </li></ul></ul><ul><ul><li>Nor always by excess shoot biomass </li></ul></ul><ul><li>Well-drained soils possess natural ability to maintain root health </li></ul><ul><ul><li>But this requires additional nutrients and water </li></ul></ul><ul><li>Most of the soils require manual / mechanical soil stirring to enhance grain yield </li></ul><ul><li>Poorly-drained soils / soils with higher organic matter require definite root aeration </li></ul>SR
  55. 55. To conclude.. <ul><li>SRI type of cultivation has definite advantages for root health </li></ul><ul><li>Like Best Management Practices, SRI practices are not adopted in full </li></ul><ul><ul><li>Constraints in SRI may lead to discontinuation in due course </li></ul></ul><ul><li>SRI may not be recommended to entire rice belt; conventional needs to continue </li></ul><ul><li>Yet, SRI can revive interest in rice farming with modifications to suit local conditions </li></ul>SR
  56. 56. SR Thanks

×