Practical management of climate variability in a changing climate Peter McIntosh, Senthold Asseng, Dean Thomas, Guomin Wan...
Overview <ul><li>Simulate growing wheat crop in southwest WA using APSIM </li></ul><ul><li>Explore two different N applica...
Nyabing
Good years decreasing
The importance of good years 80% of income in 40% of years
Simulated wheat crop 1980-2006 <ul><li>Crop simulation model APSIM-Nwheat </li></ul><ul><li>Local variety, clay soil </li>...
How much N (nitrogen fertiliser) to add? Nyabing, clay soil, 1980-2006 $2 per $1 N $1 per $1 N All years Maximize GM
Why be risk averse? 3 bad years in a row can lose the farm 1 really bad year can compromise the next 2-3
Number of years to be 95% sure of breaking even 3 years 6 years
Above median Below median  Nyabing, clay soil, 1980-2006 What if we had a rainfall forecast? All years $2 per $1 N
Potential value of a forecast Gain $59 by not fertilising in bad years (max GM only) Gain $212 (risk averse) or $134 (max ...
Seasonal forecast model - POAMA <ul><li>Predictive Ocean Atmosphere Model for Australia </li></ul><ul><li>Models the earth...
Forecast skill r=0.32 at Nyabing (significant at 90% but not 95%) 70% at Nyabing (significant at 95%) correlation (r) two-...
Use POAMA forecast to determine N Wrong forecast Below median With POAMA forecast Risk averse strategy
risk averse gain $167K max GM gain $10K 420,000 335 / 13 168 80 / 0 POAMA 2 category (maximise GM) 402,500 313 / 20 161 60...
Forecast value Planted area 2500 ha 9% $527,500 $420,000 $410,000 Maximise GM 66% $490,000 $402,500 $235,000 Risk averse F...
How long for a forecast to pay off? 7 years
How long for a forecast to pay off? 3 years
Forecast makes the most of good years 80% of income in 40% of years same income in 15% of years
Managing mixed farms with seasonal forecasts all crop all crop +FC crop/   pasture crop   +FC /   pasture crop   +FC /  pa...
3000 ha farm, duplex soil Mixed farming benefits from a POAMA forecast GM from sheep Forecast benefit
Summary <ul><li>Get much better value from a seasonal forecast using a realistic conservative management strategy </li></u...
Thank you CAWCR (The Centre for Australian Weather and Climate Research -  A partnership between CSIRO and BoM) Peter McIn...
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Practical management of climate variability in a changing climate - Peter McIntosh

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  • Fig. 4 - Example of changes in gross margins (A$ ha-1) for increasing N fertiliser applications for all May-October seasons (_____), for the above median May-October rainfall seasons only (…..) and for the below median May-October rainfall seasons only (- - - - -) for an initially dry (at start of season) clay soil at Nyabing in the Western Australian wheat-belt. Arrows indicate individual optimised N application for each group of seasons for a wheat price of A$200 t-1, N fertiliser cost of A$1 kg-1 N and a profit target of A$2 per each 1A$ invested in N fertiliser. See text for more details.
  • Fig. 4 - Example of changes in gross margins (A$ ha-1) for increasing N fertiliser applications for all May-October seasons (_____), for the above median May-October rainfall seasons only (…..) and for the below median May-October rainfall seasons only (- - - - -) for an initially dry (at start of season) clay soil at Nyabing in the Western Australian wheat-belt. Arrows indicate individual optimised N application for each group of seasons for a wheat price of A$200 t-1, N fertiliser cost of A$1 kg-1 N and a profit target of A$2 per each 1A$ invested in N fertiliser. See text for more details. Question: Is $2 per $1 incremental or total?
  • Keep sheep # constant
  • Fig. 2 - Average (1980-2006) farm gross margin (A$ farm-1) for a duplex soil at a) Nyabing and b) Katanning, Western Australia for five management strategies. The whole bar shows the total farm cross margins, the open bar shows the gross margins from the pasture (sheep) component. All Crop – whole farm under cropping; All Crop + forecast; whole farm under cropping with N fertiliser management using seasonal POAMA rainfall forecasts; Crop/Pasture – mixed crop-pasture (sheep) farm; Crop + forecast/pasture – mixed crop-pasture (sheep) farm with N fertiliser management in cropping using seasonal POAMA rainfall forecasts; Crop + forecast/pasture + forecast – mixed crop-pasture (sheep) farm with N fertiliser management in cropping and pasture area allocated using seasonal POAMA rainfall forecasts. See Table 1 for farm details. Error bars indicate standard deviation for whole farm gross margins.
  • Practical management of climate variability in a changing climate - Peter McIntosh

    1. 1. Practical management of climate variability in a changing climate Peter McIntosh, Senthold Asseng, Dean Thomas, Guomin Wang and Nirav Khimashia
    2. 2. Overview <ul><li>Simulate growing wheat crop in southwest WA using APSIM </li></ul><ul><li>Explore two different N application strategies </li></ul><ul><ul><li>maximise income (risky) </li></ul></ul><ul><ul><li>$1 N must return $2 (risk averse, realistic) </li></ul></ul><ul><li>Vary N rate using seasonal climate model forecast </li></ul><ul><ul><li>May-Oct rainfall forecast (above/below median) </li></ul></ul><ul><li>Show that the forecast </li></ul><ul><ul><li>is much more valuable for the realistic N management strategy </li></ul></ul><ul><ul><li>requires fewer good years for greater returns (climate change) </li></ul></ul><ul><li>Explore risk and payoff time for forecast </li></ul><ul><li>Explore mixed wheat-sheep farming </li></ul>
    3. 3. Nyabing
    4. 4. Good years decreasing
    5. 5. The importance of good years 80% of income in 40% of years
    6. 6. Simulated wheat crop 1980-2006 <ul><li>Crop simulation model APSIM-Nwheat </li></ul><ul><li>Local variety, clay soil </li></ul><ul><li>Reset soil moisture to no plant-available stored soil water each year </li></ul><ul><li>Reset to 50 kg mineral N per ha each year </li></ul><ul><li>Plant after enough rain (10mm over 10 days) </li></ul><ul><li>Apply nitrogen (N) at sowing (>80kg applied 4 weeks later) </li></ul><ul><li>Gross Margin (GM) = income – operating cost – N cost </li></ul><ul><li>Wheat price $200/t ( ± protein premium/penalty) </li></ul><ul><li>Operating = seed, sprays, diesel, insurance, interest etc ($150/ha) </li></ul><ul><li>N cost = $1 per kg </li></ul>
    7. 7. How much N (nitrogen fertiliser) to add? Nyabing, clay soil, 1980-2006 $2 per $1 N $1 per $1 N All years Maximize GM
    8. 8. Why be risk averse? 3 bad years in a row can lose the farm 1 really bad year can compromise the next 2-3
    9. 9. Number of years to be 95% sure of breaking even 3 years 6 years
    10. 10. Above median Below median Nyabing, clay soil, 1980-2006 What if we had a rainfall forecast? All years $2 per $1 N
    11. 11. Potential value of a forecast Gain $59 by not fertilising in bad years (max GM only) Gain $212 (risk averse) or $134 (max GM) by fertilising in good years Risk averse strategy has more to gain from a forecast risk averse gain $255K max GM gain $117K 80 / 0 60 / 0 77 / 77 0 / 0 N (kg/ha) above/below 527,500 410 / 27 211 Correct 2 category (maximise GM) 490,000 378 / 27 196 Correct 2 category (risk averse) 410,000 376 / -32 164 Climatology (maximise GM) 235,000 166 / 27 94 Climatology (risk averse) Farm Income ($/2500ha) GM ($/ha) above/below ave Strategy
    12. 12. Seasonal forecast model - POAMA <ul><li>Predictive Ocean Atmosphere Model for Australia </li></ul><ul><li>Models the earth system (atmosphere, ocean, ice, land) </li></ul><ul><li>Based on dynamics of fluids, range of physical processes </li></ul><ul><li>Start from measured state of the ocean </li></ul><ul><li>Step forward every 15 minutes for 9 months on global 250km grid </li></ul><ul><li>Predicts wind, temperature, rainfall </li></ul><ul><li>Climate change built-in </li></ul><ul><li>Start 1 May, predict May-Oct rainfall </li></ul><ul><li>1980-2006 </li></ul>
    13. 13. Forecast skill r=0.32 at Nyabing (significant at 90% but not 95%) 70% at Nyabing (significant at 95%) correlation (r) two-category hit rate
    14. 14. Use POAMA forecast to determine N Wrong forecast Below median With POAMA forecast Risk averse strategy
    15. 15. risk averse gain $167K max GM gain $10K 420,000 335 / 13 168 80 / 0 POAMA 2 category (maximise GM) 402,500 313 / 20 161 60 / 0 POAMA 2 category (risk averse) 80 / 0 60 / 0 77 / 77 0 / 0 N (kg/ha) above/below 527,500 410 / 27 211 Correct 2 category (maximise GM) 490,000 378 / 27 196 Correct 2 category (risk averse) 410,000 376 / -32 164 Climatology (maximise GM) 235,000 166 / 27 94 Climatology (risk averse) Farm Income ($/2500ha) GM ($/ha) above/below ave Strategy
    16. 16. Forecast value Planted area 2500 ha 9% $527,500 $420,000 $410,000 Maximise GM 66% $490,000 $402,500 $235,000 Risk averse Forecast efficacy Correct forecast POAMA forecast Climatology
    17. 17. How long for a forecast to pay off? 7 years
    18. 18. How long for a forecast to pay off? 3 years
    19. 19. Forecast makes the most of good years 80% of income in 40% of years same income in 15% of years
    20. 20. Managing mixed farms with seasonal forecasts all crop all crop +FC crop/ pasture crop +FC / pasture crop +FC / pasture +FC dry wet 5 options Farm 1 Farm 3 Farm 4 Farm 5 Farm 2
    21. 21. 3000 ha farm, duplex soil Mixed farming benefits from a POAMA forecast GM from sheep Forecast benefit
    22. 22. Summary <ul><li>Get much better value from a seasonal forecast using a realistic conservative management strategy </li></ul><ul><li>A moderately skilful forecast (19 out of 27 years correct) can increase farm profit from $235K to $402K </li></ul><ul><li>Using such a forecast pays off in </li></ul><ul><ul><li>7 years (at 95% certainty) </li></ul></ul><ul><ul><li>3 years (at 80% certainty) </li></ul></ul>
    23. 23. Thank you CAWCR (The Centre for Australian Weather and Climate Research - A partnership between CSIRO and BoM) Peter McIntosh Principal Research Scientist Phone: +61 3 6232 5390 Email: peter.mcintosh@csiro.au Web: www.csiro.au/cmar Contact Us Phone: 1300 363 400 or +61 3 9545 2176 Email: Enquiries@csiro.au Web: www.csiro.au
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