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Sudhir Yadav and Liz Humphreys

Tradeoffs in land and water productivity of rice with establishment method and irrigation schedule . Sudhir Yadav and Liz Humphreys. Outline Establishment method of rice Performance of DSR and AWD field experiment Model simulation Conclusion Research need.

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Sudhir Yadav and Liz Humphreys

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  1. Tradeoffs in land and water productivity of rice with establishment method and irrigation schedule Sudhir Yadav and Liz Humphreys

  2. Outline • Establishment method of rice • Performance of DSR and AWD • field experiment • Model simulation • Conclusion • Research need

  3. Rice agriculture is the engine of growth for rural and urban economies…and maintaining peace

  4. Conventional practice of growing Rice Nursery raising Puddling Transplanting

  5. Issues and Concerns • Labour cost and availability • Ground water depletion/deterioration • Energy requirement to pump groundwater • Productivity of rice • Soil and environmental health *Some of these problems can be handled by changing establishment method of rice

  6. Other practices of establishing Rice

  7. Direct seeding

  8. Drivers of different establishment method • Mechanical transplanting, WSR & DSR • labour saving - reduced costs • - timely establishment • DSR • beneficial to non-rice crops in the rotation • (e.g. wheat & maize) due to avoidance of puddling = improved soil) • opportunity to introduce conservation agriculture in rice – upland rotations e.g. rice-wheat • (zero tillage, surface residue retention = mulch)

  9. Performance of DSR in IGP DSR is considered as a “water saving technology” but the fact is- it is just an “establishment method”

  10. Increasing “drying period" Rice is very sensitive to water deficit IRRIGATION + RAIN Adapted from Bouman & Tuong 2001

  11. Punjab: “Food basket of India” Irrigated rice & wheat Rainfed rice, partially irrigated wheat Ladha et al. (2000)

  12. Water requirement of DSR vs puddled transplanted rice (PTR) Punjab, India (clay loam, deep watertable) 4 irrigation treatments - daily or soil water tension 20, 40 or 70 kPa at 15-20 cm • Regardless of establishment method, rice very sensitive to soil drying • With more water stress (>20 kPa), yield penalty was higher in DSR than PTR.

  13. Oryza2000: a rice growth simulation model for potential, water-limited, and/or nitrogen-limited conditions (lowland, aerobic rice)Effects of weather, irrigation, nitrogen fertilizer, general management, variety characteristics, soil type (hydrological, native N supply)version 2.0, 2004; and 2.13, 2009 • Fully documented • User-friendly interface (FSEWin) • Tutorial available • Standard evaluation methodology • Standard data sets available • www.knowledgebank.irri.org/oryza2000/

  14. Application of ORYZA • Calibration: from 2 year field experiment data • Evaluation: 4 irrigation regime each year • Simulation: 40 years (1970-2009) past weather data of Ludhiana, India Irrigation threshold • First 30 DAS: 2-d after disappearance of water • After 30 DAS: SWT based (10,20,..........70kPa)

  15. Performance of ORYZA2000 to predict grain yield 2008 2009 PTR 2009 2008 DSR

  16. Performance of ORYZA2000 to predict water balance components

  17. Simulation with 40 years past weather data

  18. Grain yield and IW input with different irrigation schedule

  19. Where is the water saving? (Percolation+Seepage) Can we count it under “water saving”

  20. Safe AWD- PTR vs DSR Stage 1 Stage 3 Stage 2 y = 4.14x - 396.1 R² = 0.97 y = 3.24x - 424.3 R² = 0.98

  21. Cracking in soil

  22. SWT and Cracking intensity* *measurement with WinDIASSofware

  23. Water productivity: PTR vs DSR

  24. Selection of establishment method and irrigation schedule

  25. Significance of above for irrigation system managers • The biggest gains in irrigation water saving are from adoption of safe AWD (establishment method is of secondary importance) • Safe AWD • reduced runoff, percolation & seepage (no effect on ET) • (i.e. it will not make more water available for other uses where runoff & deep drainage can be used elsewhere) • reduced irrigation requirement for DSR by ~30% compared with PTR in Punjab, India • (needs to be evaluated in other situations) • requires ability to deliver water when needed • (because of sensitivity of rice to soil drying)

  26. Research needs for AWD & DSR • irrigation scheduling for DSR • can we reduce frequency of irrigation during some crop stages & further reduce irrigation input without reducing yield? • how is this affected by soil type, climate, varietal duration etc? • develop farmer friendly techniques for AWD • Field water tube (shallow water table) • Tensiometer (deep water table) • does adoption of zero tillage & mulching in a rice-upland cropping system increase total system yield, WPi & WP of depleted water? • what are the real water savings at higher spatial scales (irrigation schemes, catchments, river basins)?

  27. Acknowledgement • Gurjeet Gill, The University of Adelaide, Australia • Liz Humphreys, International Rice Research Institute, Philippines • Tao Li, International Rice Research Institute, Philippines • S.S.Kukal, Punjab Agricultural University, India

  28. ThankYou !

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