Biochar: Science and Policy

Transcription

1 Biochar: Science and Policy Johannes Lehmann Department of Crop and Soil Sciences Cornell University

2 Biochar Information Demand and Supply

3 Biochar Information Demand and Supply

4 Biochar Old and New Cited in Brown, 2009, in Earthscan Publ.

5 Biochar Old and New without biochar with biochar Retan 1915, Forestry Quarterly 13, 25-30

6 Biochar Old and New The results have been a deeper root system, increased water efficiency, relief of sod-bound turf, increased soil aeration, improved drainage, and generally improved physical condition of the soil. Timely Turf Topics (1943)

7 Biochar Transformation Complete chemical changes Knicker, 2007, Biogeochem 85,

8 Biochar Abundance in World Soils Krull et al, 2008, in: Nova Sci Publ (World Soils Archive of ISRIC)

9 Natural Biochar Abundance in Soils Number of soils (% of all tested soils) Average 20% (n=452) NSA Lead Profiles QLD Transect DWN Transect Major Australian Cities Katherine Daly Waters 34Gt SOC (0-1m) (Grace et al., 2006, Carbon Balance and Management 1,14) Black Carbon (% of total organic C) NSA (N=58) DWN (N=280) QLD (N=114) 20% 7Gt 0.1Gt CE /yr fossil fuel (Department of Climate Care, 2008) Lehmann et al, 2008, Nature Geoscience 1,

10 Enhancing Sequestration How does biochar sequester carbon dioxide?

11 Biochar Benefits Systems Dimension Mitigation of Climate Change multiple benefits often connected Waste Management Win 4? Energy Production Soil Improvement Social, Financial Benefits

12 Corner Stones of Biochar Properties for Soil Improvement - Agronomic value (ph, solute retention, water availability (?), microbial ecology (?)) - Stability

13 Agronomic Value

14 Agronomic Value Maize grain yield (t*ha -1 ) Control 8 t * ha t * ha -1 a a a b a a Year b ab a c b a Temporal variability Maybe Julie s data here? Cite Marco! Control 8 t ha-1 20 t ha-1 Applied once in 2003 Colombian Llanos (N=3) Major, Lehmann, Rondon, unpubl. data

15 Agronomic Value Spatial variability 6 5 Conservation Traditional farming +manure 6 5 Conservation farming +biochar+fertilizer Grain Yield (t/ha) Grain Yield (t/ha) Rainfall (mm) Rainfall (mm) Eastern Zambia, 280 farmers Rice husk biochar Gatere et al., unpubl. data

16 Agronomic Value Spatio-Temporal variability Biochar Sawdust Manure Tithonia LSD 0.05 Maize grain yield (t ha -1 ) Wood biochar applied each season Kenya (n=3) Time since conversion (years) Kimetu et al., 2008, Ecosystems 11:

17 Agronomic Value Spatio-Temporal variability Biochar Sawdust Manure Tithonia LSD 0.05 Grain yield (Mg ha -1 ) Maize grain yield (t ha -1 ) Time since conversion (years) 2 0 Old conversion Medium conversion Young conversion Old conversion Medium conversion Young conversion P rate (kg P ha -1 ) N rate (kg N ha -1 ) No biochar Long rainy season Urea, TSP Kenya (n=3) Ngoze et al., 2008, Global Change Biology 14:

18 Agronomic Value Carbon recovery (% of initial C) ph Carbon recovery Optimum Temperature ( C) Lehmann, 2007, Frontiers in Ecology and the Environment 7, Variability in biochar quality (production+feedstock) Surface area CEC ph CEC (mmol c kg -1 ) Surface area (m 2 g -1 ) Biochar from black locust (N=3)

19 Agronomic Value Justus Liebig

20 Biochar Stability - Corner stone for biochar systems - Necessary yet not sufficient (for climate change mitigation)

21 Biochar Stability (a) ME Non-BC Soils (b) NY Biochar from hardwood in storage areas for historical pig iron production (130 years old) MRT of 1335 yrs at 10 C MAT Aged Hardwood Biochar Carbon Dioxide Evolution (mg CO 2 -C/gC) (c) PA (e) TN (g) AL BC Soils BC-containing soil Adjacent soil (d) OH (f) GA Days Cheng, Lehmann et al., 2008, Journal of Geophysical Research, 113, G02027

22 Biochar Stability Highly Aged Biochar C mineralization [mg CO 2 -C g -1 C] Mean residence time of 4035 yrs at 10 C MAT HAT ACU DS Open = Adjacent soil Filled = Anthrosol LSD=0.05 BC-poor soils BC-rich soils (Terra Preta Central Amazon Defined period of BC accumulation) Liang, Lehmann et al., 2008, Geochimica et Cosmochimica Acta 72, Days (N=3; BC age ranges from 800 to 7,000 years)

23 Biochar Stability Fresh Grass Biochar Inceptisols (Northern Territory, Australia) 13 and 15 profiles 27 C MAT, 887 mm MAP Grass vegetation under varying assumptions of burning severity and BC formation Model run to equilibrium (for BC MRT to 1m) 40 Soil carbon (Mg ha m -1 ) MRT of 1300 and 2600 yrs ( ) at 28 C MAT modelled No BC formation BC formation but no BC disappearance BC formation with fitted BC disappearance measured BC non- BC Time Lehmann et al, 2008, Nature Geoscience 1,

24 Biochar Stability Fresh Grass Biochar MRT of 2000 years Incubation period (days) (ryegrass biochar, n=4) Kuzyakov et al, 2009, Soil Biol. Biochem 41,

25 Important Nuances: Quality A (corn-350-bc) B (corn-600-bc) Carbon loss rate (% year -1 ) a b 350 C 600 C b b 5 nm 5 nm 0 Corn-BC Oak-BC (1 year, 30 C, in sand culture, N=8) Nguyen et al., 2009, Organic Geochemistry, in press

26 Biochar Stability and Stabilization Chemical stability + particulate nature (a) (b) 10 μm (c) (d) Total Carbon Black Carbon Lehmann et al, 2009, in: Earthscan Publ Lehmann et al, 2008, Nature Geoscience 1,

27 Biochar Stability and Stabilization Biochar Saturation (Six et al, 2002, Plant and Soil 241: ) C in Soil Ordinary organic matter (plant residues, manures, compost) C Input

28 Storage Time and Storage Capacity Biochar? Lackner, 2003, Science 300:

29 Getting the Full Picture Taking a systems perspective

30 Biochar Decomposition? 16 BC contents (mg C g -1 soil) BC= e -0.12years R 2 =0.80, P= Age (years since BC deposition) (BC from forest clearing by fire false-time series Western Kenya) Rapid disappearance ( decomposition!) Nguyen et al., 2008, Biogeochemistry 89:

31 Getting the Full Picture Disappearance ( decomposition!) Wardle et al., 2008, Science 320: 629

32 Getting the Full Picture Apparent additional CO 2 evasion by adding biochar (ryegrass biochar, incubation, 2.5 years, n=4) Kuzyakov et al, 2009, Soil Biol. Biochem 41,

33 Systems Analysis: Life Cycle Assessment System boundaries Fossil fuels production Expanding system boundaries Electricity production Pyrolysis facility T T Biomass collection Chipping Drying Slow pyrolysis Biochar Soil application T Farm equipment, agrochemicals Compost T (-) T Construction materials (-) Producer gas Syngas cleanup Excess syngas Natural gas production and combustion T (-) Fertilizer production Roberts, Lehmann et al, unpubl data

34 Systems Analysis: Energy Balance Energy balance (MJ/MJ), Slow pyrolysis Switchgrass Forage corn Corn stover (crop residue) Wheat straw Biochar to energy Biochar to soil Gaunt and Lehmann, 2008, Environmental Science and Technology 42:

35 Systems Analysis: Emission Balance Avoided Emissions (kg CO 2 /ha/yr), Slow pyrolysis Biochar to energy Biochar to soil Bioenergy crops ,551-18,595 Crop residues ,833 Gaunt and Lehmann, 2008, Environmental Science and Technology 42:

36 Total Avoided Emissions Life Cycle Analysis Total Avoided Emissions [kg CO 2 ha -1 ] % reductions in denitrification and 50% in fertilizer needs 50% reductions in denitrification and 10% in fertilizer needs No reductions Bio-char used for energy Miscanthus Bio-char half life [years] Gaunt and Lehmann, 2008, Environ. Sci. Technol. 42:

37 Costs Cost of avoided emission (US$/ton), Slow pyrolysis Cost of CO 2 Cost of Biochar Bioenergy crops Crop residues Gaunt and Lehmann, 2008, Environmental Science and Technology 42:

38 Biochar in the Public - Historical entry point: soil improvement - Focus on climate mitigation (UNFCCC, UNCCD)

39 Biochar in the Public the Gt Question 58 Gt C yr -1 CO 2 Atmosphere 800 Gt Pyrolysis 58 Gt C yr -1 Carbon-negative bioenergy Anthropogenic 7 Gt C yr -1 From Win-Win to No-Loose situation Biochar Soil 3195 Gt C Plant 654 Gt C Lehmann and Joseph, 2009, Earthscan

40 Taking Biochar Science and Policy Forward - Based on solid science - Systems perspective

41 Thanks Students, postdocs, academic colleagues Industry collaborators Policy advocates, RBI/IBI Engineering Policy Science