Johannes Lehmann Department of Crop and Soil Sciences, Cornell University John Gaunt GY Associates, UK Marco Rondon TSBF-CIAT, Cali, Colombia Bio-char Sequestration in Soil A New Frontier
Dec 16, 2015
Johannes LehmannDepartment of Crop and Soil Sciences, Cornell University
John GauntGY Associates, UK
Marco RondonTSBF-CIAT, Cali, Colombia
Bio-char Sequestration in SoilA New Frontier
Sequestration of Carbon in Soil – often a finite sink!
Year
1860 1880 1900 1920 1940 1960 1980 2000
So
il C
arb
on
[mg
g-1
]
5
10
15
20
25
30
35
40
Continuously manured
Manured from 1852-1871
No organic inputs
Hoosfield Barley Experiment, Rothamsted, UK
(Data courtesy of Rothamsted Research, UK)
Slow and finite increases of SOM
Year
1860 1880 1900 1920 1940 1960 1980 2000
So
il C
arb
on
[mg
g-1
]
5
10
15
20
25
30
35
40
Continuously manured
Manured from 1852-1871
No organic inputs
Sequestration of Carbon in Soil – often a labile sink!
Upon management changes, SOM decreases rapidly again – issue of permanency
(Data courtesy of Rothamsted Research, UK)
Hoosfield Barley Experiment, Rothamsted, UK
Bio-char Sequestration in Soil
• More permanent soil carbon sink than any suggested alternatives
• Chemical recalcitrance not constraint by ability of the soil to provide physical protection
• Easily accountable• Costs covered by improvement of soil fertility
= application of incompletely combusted organic material to soil (charcoal, biomass-derived black carbon)
Ubiquity of Bio-char (Biomass-Derived Black Carbon) in Soil
Not an alien substance!
Naturally occuring maximum concentrations 40% of soil organic matter
Australia: Skjemstad et al., 1996, Aust J Soil Res 34, 251-271 Europe: Schmidt et al., 1999, Eur J Soil Sci, 50, 351-365South Africa: Bird et al., 1999, Global Biogeochem Cycles, 13, 923-932USA: Skjemstad et al., 2002, Soil Sci Soc Am J, 66, 1249-1255USA: Glaser and Amelung, 2003, Global Biogeochem Cycles, 17, 1064
(Forest soil from Ghana)
Large amounts of stable aromatic carbon structures in Bio-char
Even very old particles of bio-char (black carbon) retain their high aromaticity. This is an indication of the recalcitrance of bio-char leading to high permanency in soil
Energy [eV]
280 285 290 295 300 305 310
Abs
orba
nce
(arb
itrar
y un
its)
Charcoal
Black C
Non-black C
aromatic-Cphenolic-C
carboxyl-Ccarbonyl-C
Lehmann et al., 2005, Global Biogeochemial Cycles 19: GB1013
Bio-char
NEXAFS spot spectra of particle center, black C from anthropogenic soil age 6,700 years(Near-Edge X-ray Absorption Fine Structure)
Energy [eV]
280 285 290 295 300 305 310
Abs
orba
nce
(arb
itrar
y un
its)
Charcoal
Black C
Non-black C
(6,700 years old)
(fresh)
Chemical Stability of Bio-char - NEXAFS
Chemical Stability of Bio-char
vvvvvvvvv
Liang, Lehmann et al., unpubl. data
Time (days)
0 50 100 150 200 250 300 350
C m
iner
aliz
atio
n [m
g C
O2-
C g
-1 C
]
0
50
100
150
200
LSD0.05
Soils with low BC (<10%)
Soils with high BC (>60%)(pairs with identical texture and mineralogy)
Soil organic carbon [g kg-1]
0 10 20 30 40 50 60 70
Pot
entia
l cat
ion
exch
ange
cap
acity
[
mm
olc
kg-1
]
0
100
200
300
400
500
forest profiles
High Cation Exchange Capacity of Bio-char
Greater CEC per unit carbon in soil with high amounts of bio-char
Sombroek et al., 2003, in Lehmann et al., Kluwer Ac Publ.
Anthropogenic Soils with >20% BC of SOC
with 1-10% BC
Carbon Forms on Bio-char ParticlesHighly aromatic in the centerOxidized near the surface
1 m Energy [eV]
280 285 290 295 300 305 310
Inside
Outside
Abso
rba
nce
(arb
itra
ry u
nits
)
PCR and cluster analysis
Lehmann et al., 2005, Global Biogeochemial Cycles 19: GB1013
(Both Unfertilized) © J
. Maj
or, 2
003
High Black CLow/no Black C
Application of bio-char >500 years BP!
Major, DiTommaso, Lehmann, Falcão, 2005, AGEE, in review
Soil Fertility of Bio-char-rich SoilsCentral Amazon, Brazil:
Opportunities for Bio-char Production
• From agricultural, forest and urban wastes• Through energy production systems using bio-fuels• From wastes of charcoal production• Within shifting cultivation
Basic Benefit of Biomass Conversion to Bio-char
Biomass carbon100%
Biomass carbon100%
Soil Soil
Bio-char carbon50%
100 years
Biomass carbon<10%
Soil Soil
Bio-char carbon>30%
Atmosphere730
Ocean38,000
Soil1500
Plants500
Geological Reservoirs5,000-10,000
Labile organic matter 300
Intermediate organic matter 1050
Stable organic matter 150
59
(IPCC, 2001)
60
1
12060
The Natural Carbon Cycle(in Pg)
Atmosphere730
Ocean38,000
Soil1500
Plants500
Geological Reservoirs5,000-10,000
Labile organic matter 300
Intermediate organic matter 1050
Stable organic matter 150
5.4
1.9
1.91.7
59
(IPCC, 2001)
60
1
Land uptakeLand usechange
12060
The Anthropogenic Disturbance
Fossil fuel
Atmosphere730
Ocean38,000
Soil1500
Plants500
Geological Reservoirs5,000-10,000
Labile organic matter 300
Intermediate organic matter 1050
Stable organic matter 150
0.16
5.41.9
1.7
Slash-and-char
Renewablefuel
Slash-and-char
Renewable fuel
-0.2
-0.2
?
59
-0.16
Agricultural waste
0.2
Renewablefuel
0.02
Agricultural waste
0.2
Waste
(Lehmann, Gaunt, Rondon, in review)
Bio-char Opportunities
Atmosphere730
Ocean38,000
Soil1500
Plants500
Geological Reservoirs5,000-10,000
Labile organic matter 300
Intermediate organic matter 1050
Stable organic matter 150
0.16
5.41.9
1.7
Slash-and-char
Renewablefuel
Slash-and-char
Renewable fuel
-0.2
?
59
-0.16
Agricultural waste
0.2
Renewablefuel
0.02
Agricultural waste
0.2
Waste
(Lehmann, Gaunt, Rondon, in review)
Land uptakeLand usechange
9.5With projected adoption of bio-fuels by 2100 (Berndes et al., 2003)
-0.2
Tradable GHG Emission Reductions
System change Net emissions Reduction FF Subst.* Em. Reductions
From: Slash-and-burn 3294
To: Slash-and-char 1702 1592 0 1592
From: Wood to soil 3666
To: Bio-char energy 1903 1763 1147 2910
From: Bio-fuel 3294
To: Bio-char energy 1903 1391 1147 2538
kg CO2 per ton woody biomass
(Lehmann, Gaunt, Rondon, in review) *for natural gas
Tradable GHG Emission Reductions
Not considered:- Emission reductions other than CO2 (e.g. CH4, N2O)- Increased biomass production
(Lehmann, Gaunt, Rondon, in review)
Tradable GHG Emission Reductions
Benefits of Bio-char sequestration over any other soil C sequestration:
(Lehmann, Gaunt, Rondon, in review)
• Easy accountability (determined by application)
• Low risk for C trading (high permanency)
• Kyoto mechanisms applicable (tradable commodity is
avoided emissions rather than sequestered C)
Key Messages
More permanent C sequestration than any other C sequestration method in soil
More effective for increasing soil fertility than any other C sequestration method in soil
More favorable to current C trading mechanisms than any other C sequestration method in soil