Biochar for climate change mitigation: the role of forest industry. Hailong Wang

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1 Biochar for climate change mitigation: the role of forest industry Hailong Wang

2 Scion A Crown Research Institute of New Zealand New Zealand Forest Research Institute Limited Based in Rotorua, Christchurch, Wellington, Auckland and Dunedin

3 Outline Introduction Forests & C sequestration Forest residues for biochar Biochar to forest soils Research needs The NZ biochar scenario

4 Global Carbon Cycle (Billions of Tonnes Carbon)

5 NZ Gross CO 2 Equivalent Emissions > 70 million t/yr aspx

6 Pathways for mitigating GHG emission in NZ Development of renewable energy

7 Growing more forests Carbon forests

8 Using biochar for soil C sequestration carbon negative! Source: Lehmann, Nature Vol. 447 p144 (10 May 2007).

9 To achieve the C negative goal using biochar: Biochar has to be lasting in soil, and Biochar has to be produced from biomass that would otherwise have oxidised in the short to medium term. Photo: P. Hall

10 NZ biochar feedstock potential - dry t/yr ¾ potentially available biomass are from plantation forests Municipal soild waste, putrescible , 4% Municipal biosolids 73000, 2% Fruit and vegetable culls , 2% Straw , 10% Forest residues easily accessible , 25% Municipal wood waste , 5% Wood processing residues without markets , 8% Forest residues hard to access , 16% Wood processing residues with markets , 27% Source: Hall & Shrubsole 2009

11 Forests are the key for successful implementation of using biochar to sequester C in NZ Biomass Gas/energy focus Char focus Feedstock Dry t/yr C in Char, t C in Char, t Forestry residues 3,608, , ,880 2,251,031 3,111,720 t/co 2 e Other biomass total 1,196, , , , ,512 t/co 2 e Source: Hall & Shrubsole 2009

12 Benefits of adding biochar to soil Increase C sequestration Increase crop yields Increase retention of nutrients Increase mineral nutrition (e.g. K) Increase retention of chemicals Photo: P. Hall

13 e.g., biochar addition improved soil adsorption of herbicide terbuthylazine (TA) (Wang et al. 2010) Control (soil only) Soil + 1% biochar

14 Other effects of adding biochar to soil Increase soil biological activities Liming effect Enhance moisture retention Increase porosity - aeration Increase soil temperature It may stimulate soil organic matter decomposition, and reduce the net biochar C sequestration, especially in soils rich in SOC, e.g., NZ pasture soils

15 Current research on biochar Nearly all studies conducted in agricultural soils Little work on applying biochar to forest soils Photo: P. Hall

16 Advantages of applying biochar to forest soils Low C footprint: on-site production and application with minimal transportation Flexibility surface application: potentially high loading rates, or incorporation into soil, and Nursery application

17 Research needs Effect of biochar production and application on the biodiversity of forest soil ecosystems, e.g., fungi, birds Maximising the GHG mitigation effects through biochar addition to the forest soils

18 e.g., biochar may increase mycorrhizal fungi growth Biochar provides a living ecosystem Ogawa Kansai Environmental

19 My hypothesis: Biochar in forest soil: Biochar mycorrhizae bacteria more C No Charcoal Native soil C Biochar C Biomass C Mycorrhizal C Glomalin Soil OM Charcoal Mycorrhiza formation on Dipterocarps root Ogawa Kansai Environmental

20 Summary Plantation forests provide an ideal platform for mitigation of GHG emission Direct C sequestration: Woody biomass production Already recognised as C credits in ETS Soil C sequestration Supply of most abundant feedstock for biochar production Additional C sequestration by storing biochar in soil However, it is a challenging opportunity due to lack of research

21 A New Zealand biochar scenario Mobile pyrolysis unit operation in newly harvested forests On-site pyrolysis of forest residues Syngas for powering the process energy self-sufficient Bio-oil for offsite refining Biochar returned to forest soils (or nearby agricultural land) Biochar in forest soil more mycorrhizal fungi less SOC decomposition more efficient nutrient use healthier trees higher growth rate more C sequestration in the forests

22 Photo: P. Hall Photo: P. Hall