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Annie kavanagh


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Annie kavanagh

  1. 1. <ul><li>Climate Change, Compost and Horticulture </li></ul><ul><li>Annie Kavanagh </li></ul><ul><li>Sustainability Programs </li></ul>
  2. 2. Acknowledgement <ul><li>This presentation is largely based on the work undertaken by Johannes Biala of The Organic Force, commissioned by the NSW Department of Environment, Climate Change and Water. </li></ul>
  3. 3. Climate Change, Compost and Horticulture <ul><li>Australian climate change overall </li></ul><ul><li>Horticulture and Greenhouse gases </li></ul><ul><li>Carbon story and nitrogen story </li></ul><ul><li>Bringing you the good news of compost </li></ul>
  4. 5. CSIRO Australian Update <ul><li>Less rainfall </li></ul><ul><li>Climate changes: more hot days average increase 0.9 O C, more fires </li></ul><ul><li>Sea level rises- 0.5 to 2m by 2100 </li></ul>
  5. 8. Sea Level Rises and Coastal Erosion
  6. 9. Coastal erosion hot spots Collaroy/Narrabeen Warringah Council Mona Vale Pittwater Council Bilgola Pittwater Council Wamberal/Terrigal Gosford City Council Norah Head Wyong Shire Council Noraville Wyong Shire Council The Entrance North Wyong Shire Council Winda Woppa, Jimmys Beach Great Lakes Council Batemans Bay Eurobodalla Shire Council
  7. 10. Greater temperature extremes
  8. 11. Plants and climate change
  9. 12. GHG Emissions from Agriculture <ul><li>Livestock 67% </li></ul><ul><li>Ag soils 17% </li></ul><ul><li>Manure management 3.9% </li></ul><ul><li>Ag N 2 O is 85.8% national N 2 O emissions </li></ul>
  10. 14. Soil C loss <ul><li>Natural between 40 and 400 t/ha </li></ul><ul><li>Av rate of decline ~50% </li></ul><ul><li>Caused by accelerated mineralisation, erosion, leaching </li></ul>
  11. 15. Nitrogen and Climate Change <ul><li>Denitrification main source of N 2 O </li></ul><ul><li>Emissions affected by: </li></ul><ul><li>Moisture & aeration </li></ul><ul><li>Temperature </li></ul><ul><li>Soluble C </li></ul><ul><li>Fertiliser input </li></ul><ul><li>Soil pH </li></ul>
  12. 16. Peat
  13. 17. The Good News
  14. 18. Potential for Mitigation from Agriculture <ul><li>Improved practices that increase yields and generate more inputs of C residue </li></ul><ul><li>More efficient N use, geared to crop needs </li></ul><ul><li>Measures to reduce erosion </li></ul><ul><li>Restoration of degraded agricultural land </li></ul><ul><li>Global mitigation potential by 2030 ~ 4,500 – 6,000 Mt CO 2 -e yr – 89% from soil C sequestration. </li></ul>
  15. 19. Benefits of Diversion <ul><li>In Australia in 2007, approximately 4.28 Mt CO2 –e saved by diverting organics from landfill, almost the same as was as recovered as landfill gas (4.5 Mt CO2-e). </li></ul>
  16. 20. Diversion Benefits: Greenhouse Gas Savings <ul><li>2008-2009 </li></ul><ul><li>In NSW removing organics from landfill saved 277,000 tonnes of CO2-e </li></ul><ul><li>That’s more than 5.5 billion black balloons </li></ul>
  17. 21. Soil Carbon Pools <ul><li>10% fast - short turnover time, with fast decomposition, daily to annual; also known as labile or active pool </li></ul><ul><li>40-80% slow - longer turnover time, with slower decomposition, annual to decadal; also known as stable or humus pool </li></ul><ul><li>10-50% passive - longer turnover time, decadal to centennial/millennial; also known the recalcitrant or refractory pool. </li></ul>
  18. 22. Using Compost <ul><li>Around 50% of C contained in raw materials is retained and found in compost, mostly in recalcitrant organic compounds such as humic substances </li></ul>
  19. 23. Maintaining Soil C <ul><li>To retain current soil organic levels: </li></ul><ul><li>Mature garden organics compost (used on silty loam) 4.8 t DM ha-1 yr-1 </li></ul><ul><li>Mature biowaste (garden/food organics) compost (used on loamy sand) 3.8 t DM ha-1 yr-1 </li></ul><ul><li>Pasteurised biowaste (garden/food organics) compost (used on silty clay loam) 2.6 t DM ha-1 yr-1. </li></ul>
  20. 24. Carbon sequestration <ul><li>An interim climate mitigation measure: </li></ul><ul><ul><li>45% of C applied lasts 20 years </li></ul></ul><ul><ul><li>35% over 50 years </li></ul></ul><ul><ul><li>10% over 100 years. </li></ul></ul>
  21. 25. BUT… <ul><li>Carbon sequestration resulting from compost use can be considered as an interim climate change mitigation measure. </li></ul><ul><li>Provides an opportunity for implementing low-cost measures that are immediately available and deliver a wide range of other environmental, agronomic and societal benefits. </li></ul><ul><li>Could provide some “breathing space‟, and be used to complement other mitigation measures and low carbon technologies. </li></ul>
  22. 26. Nitrogen use <ul><li>Continuous compost use will increase nitrogen use efficiency in the initial year after compost application, with a maximum of 40% measured after 21 years of compost use </li></ul><ul><li>Mineralisation from mature composts usually occurs faster than from fresh composts, </li></ul>
  23. 27. Combined Effects of Sequestration and Fertiliser Replacement <ul><li>By adding compost at the rate of 10 t DM ha-1 the following savings can be made </li></ul><ul><li>~ 5,224 kg CO 2 -e in 20 years </li></ul><ul><li>~ 3,710 kg CO 2 -e in 50 years </li></ul><ul><li>~ 1,187 kg CO 2 -e in 100 years </li></ul>
  24. 28. Bonus Savings! <ul><li>Reduced micronutrients </li></ul><ul><li>Reduced agricultural lime </li></ul><ul><li>Reduced gypsum </li></ul><ul><li>Reduced use of ‘humic’ additives </li></ul><ul><li>Reduced need for irrigation (pump electricity) </li></ul><ul><li>Improved tilth – reduced tractor fuel </li></ul><ul><li>Reduced biocides </li></ul><ul><li>Reduced soil erosion </li></ul><ul><li>Increased yields </li></ul>
  25. 29. But wait – there’s more! (NSW 2008-2009) $33 million $11.85 m water $11m phosphate replacement $3.3m avoided urea $1.3m reduced acidification $1m due to reduced salinity
  26. 30. Take Home Messages <ul><li>Let nature do it! Let nature help by providing cost effective, interim climate change mitigation for the next 20+ years. </li></ul><ul><li>Diversion of organics nationally saves almost as much as landfill gas capture does (nearly 4.5 Mt /year). </li></ul><ul><li>For 1t DM compost applied per hectare - 118 kgs of CO 2 -e saved. </li></ul><ul><li>It’s not all about C, compost delivers a number of other environmental benefits. </li></ul>
  27. 31. Thank you, and for the earth’s sake, good composting!
  28. 32. Further Information: Information, resources and case studies http:// http://
  29. 33. Annie Kavanagh DECCW Ph: (02) 8837 6016