This presentation was presented during the 3 Parallel session on Theme 2, Maintaining and/or increasing SOC stocks for climate change mitigation and adaptation and Land Degradation Neutrality, of the Global Symposium on Soil Organic Carbon that took place in Rome 21-23 March 2017. The presentation was made by Ms. Annette Cowie, from UNCCD – SPI - Australia, in FAO Hq, Rome

1. Annette Cowie with input from
Lukas Van Zwieten, Johannes Lehmann, Gerard Cornelissen,
Bhupinderpal Singh, Ruy Anaya de la Rosa, Stephen Joseph
Biochar for sustainable land management
and climate change mitigation

2. Amazonian Terra preta soils
Source: www.biochar-international.org
Terra preta (dark earth) soils
High plant productivity
High organic carbon
– stable char (black carbon)

3. Pyrolysis-Biochar System
Lehmann, 2007, Frontiers in Ecol Env

5. China, Xiaoyu Liu

6. Recalcitrant
National Biochar Initiative: E Krull CSIRO

7. Recalcitrant
Source: S. Joseph UNSW
Source: E Krull CSIRO

8. Biochar = Fundamentally altered chemistry
Lehmann et al., 2010, in: Imperial College Press,
London
O+
CO+
O
O
C
O+
CH
C
C
C
C
CH
O
CH+
C
O
OH
O
OH
O
O
H
O
O
C
H
3
O
H
OH
O
H
OH
OH
O+
C
O+
O
O
C
O+
CH
C
C
C
C
CH
O CH+
C
O
OH
O OH
O
H
O
O
C
H
3
O
H
OH
OH
O O
H
O+
CO+
O
O
C
O+
CH
C
C
C
C
CH
O
CH+
C
O
OH
O OH
O+
O
H
O
O
C
H
3
O
H
OH
OH
O
H O
O+
C
O+
O
O
C
O+
CH
C
C
C
C
CH
O
CH+
C
O
OH
O OH
O
O
H
O
O
C
H
3
O
H
OH
OH
O
H OH
O+
CO+
O
O
C
O+
CH
C
C
C
C
CH
O
CH+
C
O
OH
O
OH
O
O
H
O
O
C
H
3
O
H
OH
O
H
OH
OH
H2O
CO, CO2, CH4
volatile organics O
O
OH
O O
O
OCH2
OH
OH
OH
O OH
OH
O
OH
O
+ CH3
HO
CH
+
O
OH
O
OH
HO
HO
OH
OH
O
O
OH
OH
OH
n
O
H
H
H
H
OH
H OH
O
OH
O OH
H
H
H
OH
H
OH
OH
OH
Cellulose, Lignin etc. Amorphous Carbon Turbostratic Carbon
O/C 0.7 0.5 0.3 0.1
H/C 1.5 1.0 0.5 0.3
Temperature ~200°C ~400°C ~600°C
RelativeProportion
Pyrolysis Intensity

9. Small labile fraction
Stable biochar-carbon
Mean residence time: 130 -1800 years
BP Singh NSW DPI

10. Biochar stability -
a function of feedstock and pyrolysis conditions
Least stable
(~100 years)
Most stable
(~2000 years)
Fusedaromaticrings
Mineral nutrient content
Pyrolysis temperature
550°C wood (A or NA)
400°C manures (poultry, cow) (NA)
400°C wood (A or NA)
550°C leaf (A)
550°C paper sludge (A)??
Carboncontent
400°C leaf (A)
550°C poultry (A)
550°C cow (A)
Synthesis: “after E. Krull”
BP Singh et al. 2012 (EST)

11. Persistence closely related to molar H: Corganic
Budai et al., 2013

12. 0.5
1.0
1.5
2.0
2.5
3.0
3.5
Wetweight(g)
-N +N
CharA CharB Control CharA CharB Control
Poultry litter char applied to
radish Y. Chan 2007
Paper sludge char applied to wheat
L. Van Zwieten 2007
Lukas Van Zwieten NSW DPI

13. Yield Effects of Biochars
Jeffery et al, 2011
Meta-analysis
−28% to +39%, with a mean increase of 10%.

14. 0 ton/ha
5 ton/ha
15 ton/ha
Acid soil: pH 3.6
Cacao shell biochar on ultisol,
Lampung, Sumatra
No biochar
Cacao Biochar
15 t/ha
pH 3.6 4.7
K 5.5 47
Base saturation (%) 19 51
«toxic» Aluminium 2.3 0.7
Biochar has acid neutralising capacity
(liming effect)
n=75; p < 0.001; r2=0.44
Gerard Cornellisen, NGI

15. Biochar increases soil moisture
Biochar
Min till
(hoe basins)
Conv till
Two months in growth season in Zambia
continuous monitoring with TDR
Gerard Cornellisen, NGI
Martinsen Mulder Shitumbanuma Sparrevik Børresen Cornelissen. Farmer-led maize biochar trials: effect on crop yield and soil nutrients under
conservation farming. J. Plant Nutr. Soil Sci. 2014
Cornelissen Martinsen Shitumbanuma Alling Breedveld Rutherford Sparrevik Hale Obia Mulder. Biochar Effect on Maize Yield and Soil
Characteristics in Five Conservation Farming Sites in Zambia. Agronomy, 2013.

16. Biochar can increase Cation Retention
(Exchange Capacity)
0
200
400
600
800
1000
1200
350oC 600oC 350oC 600oC
Corn-BC Oak-BC
After incubation
Initial BC
b
c
c
a
F
*
*
*
*
600o
C350o
C350o
C 600o
C
CECp(mmole(+)kgC-1)
Nguyen and Lehmann, 2009, Organic
Geochemistry
Lower PyTemp = greater initial CEC
= greater oxidation
= lower persistence
Trade-off!
N=4
30°C incubation
1 year

17. Nutrient enrichment with urine in fertile soil, Nepal
Hans Peter Schmidt, Bishnu Hari Pandit, Vegard Martinsen, Gerard Cornelissen, Pellegrino Conte, Claudia I. Kammann. Fourfold
Increase in Pumpkin Yield in Response to Low-Dosage Root Zone Application of Urine-Enhanced Biochar to a Fertile Tropical Soil.
Agriculture 2015, 5, 723-741.
All treatments had
10.5 t/ha cow
manure compost.
Biochar applied at
750kg/ha, to planting
pits
Nutrient-enriched biochar
effective at low rates

18. Lower uptake of toxic compounds (PAHs)
in worms and crops
Jakob L., T. Hartnik, T. Henriksen, M. Elmquist, R. Brändli, S.E. Hale and G. Cornelissen, (2012) Chemosphere 2012, 88, 699-705.
GAC: granulated activated carbon
PAC: powdered activated carbon
Other studies show
immobilisation of heavy metals

19. Soil C stocks increase beyond stable C addition from
biochar (in Ferralsol)
fert
fert
4
4.5
5
5.5
6
6.5
7
no char no char +
fert
fresh
biochar +
aged
biochar +
fert
fresh +
aged
biochar +
green
waste
biochar +
fert
Soilcarbon%
Apr-07
Oct-09
Sept-14
7.5
LSD= 0.52 (p=0.05)
L. Van Zwieten

20. -150
-100
-50
0
50
100
8.2 8.3 8.4 8.5 8.6 8.7 8.8 8.9 9 9.1 9.2 9.3 9.4 9.5
Biochar still reduced soil C loss even after 9.5 year
incorporation (in Ferralsol)
Years after application
DifferenceincumulativeSOCmineralisation
(gCO2-Cm-2)
(b) Plant-Soil-Biochar
(a) Plant-Soil
Positive priming
Negative priming
Weng Z (Han), Van Zwieten L, Singh B-P, Tavakkoli E, Joseph S,
Macdonald LM, Rose TJ, Rose MT, Kimber SWL, Morris S, Cozzolino D,
Araujo JR, Archanjo BS, Cowie A(2017) Biochar built soil carbon over a
decade by stabilising rhizodeposits. Nature Climate Change (in press).

21. Field study on plant-biochar interactions on priming
Multi-collar micro-plot Periodic 13C pulse-labellingSoil + Root respiration collar
Wollongbar Primary Industries Institute,
Australia
Weng, Z., Van Zwieten, L., Singh, B.P., Kimber, S., Morris, S., Cowie, A., Macdonald, L.M., 2015. Plant-
biochar interactions drive the negative priming of soil organic carbon in an annual ryegrass field system.
Soil Biology and Biochemistry 90, 111-121.

22. (a) Unamended control (b) Dosed with biochar 9.5 years ago
Lower13CO2
4.6 + 3.6
Higher13CO2
8.9 + 3.1
r-
13C labelled
190
Recovered
81 + 14
13C labelled
190
Recovered
109 + 16
R
34.3 + 2.5
F
5.2 + 4.4
O
23.6 + 3.5
M
41.4 + 2.0
R
18.7 + 2.3
F
7.9 + 5.7
O
16.5 + 2.5
M
29.5 + 0.5
r-
r-
r-
r-r-
r-r-
*
*
*
*
*

23. 13C 13C 13C
13C
13C 13C
13C
13C
13C
r
13C 13C
13C
13C
13C
13C 13C
13C
13C
13C
1.
2.
(a) Unamended control (b) Dosed with biochar 9.5 years ago
Higher13CO2
8.9 + 3.1
Co-metabolism
Dissolution of mineral-
protected new C
Lower metabolism
Enhanced organo-
mineral protection
Lower13CO2
4.6 + 3.6
B
r r
B
B
B
13C
r-
r- r-
r- r-
r-
13C labelled
190
Recovered
81 + 14
13C labelled
190
Recovered
109 + 16
1.
2.
R
34.3 + 2.5
F
5.2 + 4.4
O
23.6 + 3.5
M
41.4 + 2.0
R
18.7 + 2.3
F
7.9 + 5.7
O
16.5 + 2.5
M
29.5 + 0.5
r-
r-
r-
r-r-
r-r-
*
*
*
*
Weng Z (Han), Van Zwieten L, Singh B-P, Tavakkoli E, Joseph
S, Macdonald LM, Rose TJ, Rose MT, Kimber SWL, Morris S,
Cozzolino D, Araujo JR, Archanjo BS, Cowie A(2017) Biochar
built soil carbon over a decade by stabilising rhizodeposits.
Nature Climate Change (in press).

24. Nitrous oxide measurement

25. Cayuela et al, 2015
Biochar can reduce soil N2O emissions
Average -54%

26. Biochar lowers N loss from composting
Treatments
Proportion N emitted as
NH3
Proportion
of N lost in other
forms
% of initial N % of initial N
Control 5.6 ± 1.1 26 ± 2.7
GWBC 2.3 ± 0.1 13 ± 2.1
PLBC 2.5 ± 0.1 19 ± 5.3
Eunice Agyarko-Mintah, Annette Cowie , Lukas Van Zwieten, Bhupinder Pal Singh, Robert Smillie, Steven
Harden, Flavio Fornasier (2016). Lowering Ammonia Emissions from the Composting of Poultry Litter through
the use of Biochar, Waste Management

27. Transport
Soil
amendment
Pyrolysis to
biochar and
syngas
Distribution of
biochar
Distribution of
energy carrier
Energy service
(heat, electricity)
Biomass
residue
Biochar system
Transport
Biomass
residue
Fossil
energy/carbon
source
Extraction
Conversion to
energy carrier
Distribution of
energy carrier
Energy service
(heat, electricity)
Soil
amendment
Fertiliser
manufacture
Transport
Composting
Reference system
Distribution of
compost
Distribution of
fertiliser

28. Factors contributing to GHG abatement
Greenwaste biochar applied to canola
Poultry litter biochar applied to broccoli

29. Biochar Persistence and Soil Fertility
Greater Persistence
Lower Persistence
Change to soil persists (positive and negative)
More rapid surface oxidation
Nutrients in organic structure not released
Carbon-bound nutrients release
Lower CEC development
Nutrients transformed to inorganic are easily released
Nutrient immobilization
Johannes Lehmann

30. Biochar Suitability Mapping - Kenya
Woolf, unpubl.
Soil properties (CEC &
sand), biomass
availability, and road
access
Biochar Suitability:

31. Scaling of Biochar Systems
UnpublishedJohannes Lehmann

32. Biochar Products Today
Inoculant carrier
Compost additive
Soil-less media
Potting mixes

33. China: 100 tons of biochar-based fertilizers produced in 2016

34. GHG mitigation benefits of biochar
 Delayed decomposition of biomass
 Reduced nitrous oxide emissions from soil
 Increased soil organic matter
 Avoided fossil fuel emissions due to use of syngas as
renewable energy
 Increased plant growth
 Avoided emissions from N fertiliser manufacture
 Avoided methane and nitrous oxide emissions due to
avoided decay of residues
 Reduced fuel use in cultivation, irrigation

35. SLM benefits of biochar
 Improved soil properties – relieves soil constraints:
 chemical
 physical
 biological
 Liming effect
 Increased water holding capacity
 Increased nutrient use efficiency
 Increased plant growth, plant health
 Reduced leaching and N volatilisation
 Immobilised contaminants

36.  Different biochars – different effects
 Match biochar to soil constraints
Biochar is beneficial when
 made from sustainably harvested and renewable biomass
resources
 produced in a facility that controls emissions and
harnesses heat for efficient beneficial use to displace
GHG-intensive fuels
 applied with care, to overcome identified soil constraints
Summary:
What do we know about biochar for SLM?

37. Kontiki kiln:
Instruction
cartoon used
in Nepal,
Peru, Zambia,
Indonesia,
Uganda,
Kenya