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Peter Grace On Rangelands and Calculators

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Professor Peter Grace says carbon rich soil is "your superannuation", it's not about carbon credits, it's about productivity. He sketches the potential for rangelands to sequester carbon.
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Peter Grace On Rangelands and Calculators

  1. 1. Rangelands and GHG Calculators Peter R. Grace Queensland University of Technology Orange, NSW 19 November, 2008
  2. 4. Soil Carbon Sequestration <ul><li>Two principal approaches: </li></ul><ul><ul><li>Protecting ecosystems - Soil conservation </li></ul></ul><ul><ul><li>Manage ecosystems </li></ul></ul><ul><ul><ul><li>Reduced tillage on croplands </li></ul></ul></ul><ul><ul><ul><li>Increase inputs on degraded soils </li></ul></ul></ul><ul><ul><ul><li>Convert to pasture </li></ul></ul></ul><ul><ul><ul><li>Grazing management </li></ul></ul></ul>
  3. 5. Soil C Sequestration Overriding Influences <ul><li>Clay content </li></ul><ul><li>Precipitation </li></ul><ul><li>Temperature </li></ul>
  4. 6. Soil C vs CO 2 v Temperature vs H 2 O 6% loss in topsoil C by 2100 (Grace et al, 2006)
  5. 7. Soil C Sequestration Grazing Systems <ul><li>No definitive information - ambiguous </li></ul><ul><li>Grazed systems > Ungrazed </li></ul><ul><li>Grazing stimulates </li></ul><ul><ul><li>Aboveground growth </li></ul></ul><ul><ul><li>Belowground growth </li></ul></ul><ul><ul><li>Plant community changes </li></ul></ul><ul><li>Just as important not to promote C loss </li></ul>
  6. 8. Global Dataset – Pasture Management
  7. 9. Predicted Soil C change (0-10 cm) 6 t/ha pasture Mudgee, NSW
  8. 10. Predicted Soil C change (0-10 cm) 3 t/ha crop Mudgee, NSW
  9. 11. Constraints to Soil C Accumulation in Grazing Systems <ul><li>Low water availability - Low biomass returns </li></ul><ul><li>Low quality biomass </li></ul><ul><li>High temperatures </li></ul>
  10. 12. Constraints to Claiming Credits <ul><li>Spatial variability </li></ul><ul><li>Expensive to verify </li></ul><ul><li>Permanence </li></ul>
  11. 13. Land Use
  12. 14. Soils
  13. 15. Potential Soil C Sequestration Rangelands (0-100 cm) *SOCRATES (Grace et al., 2006) 927 253 437 TOTAL 407 111 1.48 75 Vertosol 39 11 0.12 89 Tenosol 187 51 0.74 69 Sodosol 18 5 0.12 42 Rudosol 8 2 0.74 3 Kurosol 168 46 0.51 90 Kandosol 18 5 1.23 4 Ferrosol 19 5 0.74 7 Dermosol 43 12 0.74 16 Chromosol 18 5 0.12 42 Calcarosol Total Mt CO 2 Total Mt C C increase (t/annum) Area (Mha) Soil type
  14. 16. Actual (??) Soil C Sequestration Rangelands (0-100 cm) *SOCRATES (Grace et al., 2006) Methane oxidation < 1.0 Mt CO 2 9.3 2.53 43.7 TOTAL 4.07 1.11 0.15 7.5 Vertosol .39 .11 0.01 8.9 Tenosol 1.87 .51 0.07 6.9 Sodosol .18 .05 0.01 4.2 Rudosol .08 .02 0.07 0.3 Kurosol 1.68 .46 0.05 9.0 Kandosol .18 .05 0.12 0.4 Ferrosol .19 .05 0.07 0.7 Dermosol .43 .12 0.07 1.6 Chromosol .18 .05 0.01 4.2 Calcarosol Total Mt CO 2 Total Mt C C increase (t/annum) Area (Mha) Soil type
  15. 17. Main Sources of On-Farm GHGs CH 4 CO 2 , CH 4 , N 2 O CO 2 Soil type, climate and management specific
  16. 18. Anthropogenic Sources of Methane and Nitrous Oxide Globally Total Impact 2.0 Pg C equiv 1.2 Pg C equiv Source IPCC 2001; from Robertson 2004 (compare to fossil fuel CO 2 loading = 3.3 PgC per year) Industry Industry Agricultural soils Biomass burning Cattle & feedlots Agriculture Agriculture Energy Other combustion Landfills Enteric fermentation Waste treatment Rice cultivation Biomass burning CH 4 N 2 O
  17. 19. Greenhouse Gases – in brief <ul><li>3 major gases = CO 2 , N 2 O, CH 4 </li></ul><ul><li>CH 4 has global warming impact 23 X CO 2 </li></ul><ul><li>N 2 O has global warming impact 296 X CO 2 </li></ul><ul><li>CO 2 equivalents </li></ul><ul><li>CO 2 e = 1 * CO 2 + 23 * CH 4 + 296 * N 2 O </li></ul>
  18. 20. Emissions Facts <ul><ul><li>1000 L diesel = 2.6 tonnes CO 2 </li></ul></ul><ul><ul><li>Irrigation (ca. 3 tonnes CO 2 /ha) </li></ul></ul><ul><ul><li>Cattle emit 60 kg CH 4 /yr = 1.4 tonnes CO 2 </li></ul></ul><ul><ul><ul><li>Dependent on feed quality and age of cattle </li></ul></ul></ul><ul><ul><li>1 tonne N fert emits 5 kg N 2 O = 1.5 t CO 2 </li></ul></ul><ul><ul><li>Residential electricity = 12 t CO 2 /annum </li></ul></ul>
  19. 21. On-Farm GHG Emissions <ul><li>Fuel: CO 2 </li></ul><ul><li>Cultivation: CO 2 </li></ul><ul><li>Residue decomposition : CO 2 N 2 O </li></ul><ul><li>Nitrogen application: N 2 O </li></ul><ul><li>Burning crop residues: N 2 O CH 4 </li></ul><ul><li>Biological N fixation: N 2 O </li></ul><ul><li>Waterlogging CH 4 </li></ul><ul><li>Animal emissions CH 4 </li></ul><ul><li>Urine and dung N 2 O </li></ul><ul><li>Manure management (feedlots) N 2 O CH 4 </li></ul>
  20. 22. Greenhouse Gas Inventory Darling Downs <ul><li>416 ha total </li></ul><ul><li>300 ha crop @ 84 kg N/ha </li></ul><ul><li>12 ha trees </li></ul><ul><li>100 head cattle </li></ul>
  21. 23. 1 1.25% loss 154.0 Direct loss Fertiliser N 2 O 1 12.6 Dung and faeces 8.9 Dryland 492.5 TOTAL -47 Trees Sinks CO 2 138 Animals CH 4 106.4 Diesel 10.8 Petrol 0.2 Electricity Fuel/power CO 2 58.2 Irrigated 8.2 Dryland Soil CO 2 3.5 Leaching 12.2 Atmos. Deposit Other N 2 O 1 7.1 Irrigated cotton 19 Irrigated cereal 0 Pasture Crop N 2 O 1 Total CO 2 (e) (tonnes) Source Category
  22. 24. 1 0.5% loss 61.5 Direct loss Fertiliser N 2 O 1 12.6 Dung and faeces 8.9 Dryland 431.5 TOTAL -47 Trees Sinks CO 2 138 Animals CH 4 106.4 Diesel 10.8 Petrol 0.2 Electricity Fuel/power CO 2 58.2 Irrigated 8.2 Dryland Soil CO 2 3.5 Leaching 12.2 Atmos. Deposit Other N 2 O 1 7.1 Irrigated cotton 19 Irrigated cereal 0 Pasture Crop N 2 O 1 Total CO 2 (e) (tonnes) Source Category
  23. 25. Nitrous oxide (N 2 O) <ul><li>Nitrogen gas emitted from added N sources </li></ul><ul><li>Nitrogen fixation </li></ul><ul><li>Nitrification (ammonium to nitrate) </li></ul><ul><li>Denitrification (nitrate to nitrogen gases) </li></ul>
  24. 27. Portable Greenhouse Gas Monitoring
  25. 28. Global Greenhouse Gas Network
  26. 30. Reducing N 2 O Emissions - Benefits <ul><li>N 2 O reductions are </li></ul><ul><ul><li>immediate and permanent </li></ul></ul><ul><ul><li>possible across a very wide range of crop lands and geographic areas </li></ul></ul>
  27. 31. Greenhouse Gas Inventory <ul><li>Soil carbon change ( Gross C sequestration) </li></ul>
  28. 32. Greenhouse Gas Inventory <ul><li>Soil carbon change ( Gross C sequestration) </li></ul><ul><li>CO 2 from fuel (planting, cultivation, harvesting, chemicals) </li></ul>
  29. 33. Greenhouse Gas Inventory <ul><li>Soil carbon change ( Gross C sequestration) </li></ul><ul><li>CO 2 from fuel (planting, cultivation, harvesting, chemicals) </li></ul><ul><li>N 2 O from N fertilizer applied, N fixed and other N losses (leaching etc) </li></ul>
  30. 34. Greenhouse Gas Inventory <ul><li>Soil carbon change ( Gross C sequestration) </li></ul><ul><li>CO 2 from fuel (planting, cultivation, harvesting, chemicals) </li></ul><ul><li>N 2 O from N fertilizer applied, and other N losses </li></ul><ul><li>N 2 O and CH 4 from burning </li></ul>
  31. 35. Greenhouse Gas Inventory <ul><li>Soil carbon change ( Gross C sequestration) </li></ul><ul><li>CO 2 from fuel (planting, cultivation, harvesting, chemicals) </li></ul><ul><li>N 2 O from N fertilizer applied, and other N losses </li></ul><ul><li>N 2 O and CH 4 from burning </li></ul><ul><li>CH 4 from animals </li></ul><ul><li>Net carbon sequestration = 1 - (2+3+4+5) </li></ul>
  32. 36. SE Australia Greenhouse Gas Assessment
  33. 37. Carbon Sequestration (no-till) South-East Australia (0-30 cm)
  34. 41. Calculator website <ul><li>www.isr.qut.edu.au </li></ul>
  35. 42. Calculator website <ul><li>www.isr.qut.edu.au </li></ul>
  36. 43. Take home messages! <ul><li>High temperatures, low rainfall - difficult environment to sequester significant carbon mass </li></ul>
  37. 44. Take home messages! <ul><li>High temperatures, low rainfall - difficult environment to sequester significant carbon mass </li></ul><ul><li>Rangelands and pastures may offer some benefit, but their usefulness will depend on market opportunities </li></ul>
  38. 45. Take home messages! <ul><li>High temperatures, low rainfall - difficult environment to sequester significant carbon mass </li></ul><ul><li>Rangelands and pastures may offer some benefit, but their usefulness will depend on market opportunities </li></ul><ul><li>Verification and transaction costs are high </li></ul>
  39. 46. Take home messages! <ul><li>High temperatures, low rainfall - difficult environment to sequester significant carbon mass </li></ul><ul><li>Rangelands and pastures may offer some benefit, but their usefulness will depend on market opportunities </li></ul><ul><li>Verification and transaction costs are high </li></ul><ul><li>Whole farming systems approach with all gases is ESSENTIAL </li></ul>
  40. 47. Take home messages! <ul><li>High temperatures, low rainfall - difficult environment to sequester significant carbon mass </li></ul><ul><li>Rangelands and pastures may offer some benefit, but their usefulness will depend on market opportunities </li></ul><ul><li>Verification and transaction costs are high </li></ul><ul><li>Whole farming systems approach with all gases is ESSENTIAL </li></ul><ul><li>Increased N use efficiency is a must for reducing your greenhouse gas signature </li></ul>
  41. 48. Take home messages! <ul><li>High temperatures, low rainfall - difficult environment to sequester significant carbon mass </li></ul><ul><li>Rangelands and pastures may offer some benefit, but their usefulness will depend on market opportunities </li></ul><ul><li>Verification and transaction costs are high </li></ul><ul><li>Whole farming systems approach with all gases is ESSENTIAL </li></ul><ul><li>Increased N use efficiency is a must for reducing your greenhouse gas signature </li></ul><ul><li>Maintaining soil C is key to long term productivity and profitability </li></ul>
  42. 49. Questions?

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