Biochar, Biomass, Soil and Agriculture - Information for public adoption

Introduction to Biochar

1. Biochar
Is it a viable option for soil C stabilization and sequestration?

2. The Carbon Cycle
Four Reservoirs of Carbon:
1.Sedimentary Rock
2.Ocean
3.Land Surface
4.Atmosphere
Eachofthesereservoirs
“breathes”CO
2causing
atmosphericCO
2tovaryover
time.

3. Carbon Cycle
Units in GtC

4. Carbon Sequestration
Geologicalsequestration:storingcarbondioxideindepletedgasandoilreservoirs
keepingitbeneaththeearth’ssurface
Carboncaptureandstorage:involvesCO
2beingdirectlytakenfrompowerplant
exhauststreamsandinjectedintoporousgeologicalformationsdeepintheEarth

5. What we know: Terra Preta
Marris. 2006. Nature 442: 624-626; Lehmann, et al., 2003. Plant Soil 249: 343-357; Lehmann,
et al., 2003. Kluwer Academic Publishers. 105-124.
• fine dark loamy soil
-up to 9% carbon, (adjacent soil 0.5% C)
-high nutrient content and high fertility
-3 times the phosphorous and nitrogen
• developed over thousands of years by human
habitation correspond to ancient settlements
•resultsfromlong-termmulchingofcharcoal
productionfromhearthsandbonefragments
withsoilapplication
• persistents in soil, recalcitrant, resistant to
decomposition.
Terra preta do indio or the “black earth of the Amazons”
• forest fires and slash-and-burn contribute
very low amounts of charcoal (~3%)

6. Figure 3. Biochar particles in a dark earth from the Amazon,
with dimensions of several tens of microns to submicrons. Upper
left side shows a quartz grain, inset shows separated biochar
particles. Note the coatings of biochar particles with minerals in
their natural assemblage.
from Lehmann, (2007), Front. Ecol. Environ. 5:381-387.
What we know: Terra Preta

7. Biochar may come to
the rescue....
….and whatis biochar....? ??

8. What is Biochar?
-carbon-rich solid -a byproduct
of low-temperature pyrolysis
of biomass.
-also known as charcoal,
biomass derived black
carbon, Agrichar.
-formed under complete or
partial exclusion of oxygen
at low temperatures between
about 400 and 500º C.
-Origins -has been used for centuries
-Cooking, health, water purification, etc
Active research into soil benefits was renewed by Johannes Lehmann at Cornell
University in about 1998 resulting from studies of Terra preta soils of the Amazon.
Peanut hull biochar

9. It is ...
•Whenbiomassisburntintheabsenceofoxygen,
pyrolysisoccursandthebiomasscanbeturnedintoa
liquid(‘bio-oil’),agasandahigh-carbon,fine-grained
residue:biochar.
•Biocharisfinelygroundcharcoalwithsomesimilarities
toactivatedcharcoal.
•Biocharoffersanextremelyhighsurfaceareatosupport
microbiotathatcatalyseprocessesthat,amongother
things,reducenitrogenlossandincreasenutrient
availabilityforplants.(Winsley,2007)

10. Comparison to Activated Charcoal
Activatedcharcoalischarcoalthathasbeen
madefromwoodorothermaterialsthathave
beenexposedtoveryhightemperaturesinan
airlessenvironment.
Treatedwithoxygen,opensup
millionsoftinyporesbetweenthe
carbonatoms.
Theuseofspecialmanufacturing
techniquesresultsinhighlyporouscharcoals
thathavesurfaceareasof300-2,000m2g-1.
Arewidelyusedtoadsorbodorousorcolored
substancesfromgasesorliquids.

11. Any source of biomass:
• Rice husks
• Nut shells (groundnut, hazelnut, macadamia nut,
walnut, chestnut, coconut)
• Bagasse from sugar cane production
• Olive or tobacco waste
• Wood chips, sawdust, bark, etc
• Animal manure
• Peanut hull
• Grasses and corn stover
• Other –sewage sludge tires, peat, lignite, coal
Potential Feedstocks of Biochar
*Notallorganicbiomassissuitableforproducingbiochar
Household,municipalandindustrialwastemaycontain
heavymetalsororganicpollutantswhichcouldcause
environmentalcontaminationbylandapplicationofthe
resultingbiochar.

12. Biochar Production
Temp &
Duration
Solid
(Biochar)
Liquid
(Bio oil)
Gas
(Syn Gas)
Slow
Pyrolysis
~500C
Days
35% 30% 35%
Fast
Pyrolysis
~500C
Seconds
12% 75% 13%
Gasification>800C
Hours
10% 5% 85%
CHP Gasification Slow Pyrolysis (retort) Slow pyrolysis (kiln)

13. Biochar Production
Eprida: Hydrogen and Char Fertiliser via Pyrolysis
Dynomotive:
Bio oil via
Fast
Pyrolysis
BEST Energies: Biochar via Slow Pyrolysis
University of Hawaii:
Flash Carboniser (Fast Pyrolysis)

14. from Lehmann, (2007), Front. Ecol. Environ. 5:381-387.
Low temperature pyrolysis with biochar C
sequestration

15. Biochar does not
degrade in soils
•Compostandotherorganic
materialinsoilsisvaluablebut
mineralises(convertstoCO
2)in
justafewyears.
•Biochar will remain
essentiallyunchanged for
hundredsoreventhousandsof
years–carbonsequestration
reallyispossible

16. Charcoal occurs
naturally in soils
•Up to 35 per cent of SOC in
some US soils is charcoal from
natural processes (Skjemstad
et al, 2002)
•Natural charcoal in the US
midwest prairie soils, a result
of ten thousand years of
prairie fires, may play a role in
these soils’ high and sustained
fertility
•Our results provide clear evidence that
immediately after wildfire fresh charcoal can
have important effects in Boreal forest
ecosystems dominated by ericaceous dwarf
shrubs, and this is likely to provide a major
contribution to the rejuvenating effects of
wildfire on forest ecosystems.
(Wardle et al, 1998)

17. 80 per cent of Africans
rely on biomass
for energy
Charcoal market in Khartoum, Sudan
Uganda has lost half
its forest cover in the
last ten years; 97 per
cent of the
population uses
charcoal and
firewood for cooking;
charcoal production
creates 20,000 jobs

18. ‘Slash and burn’ to
‘slash and char’
Over2billionpeoplerelyon
traditionalbiomassforheating
andcookingusinginefficientand
dirtystovesoropenfires.
Improvedstovesthatareclean
andcanalsomakecharcoalcould
improvehealth,reducemortality
andassistinagricultural
transformation
Third generation cooking stove:
Low pollution, production of biochar
(Flanagan and Joseph)

19. Scanning Electron Microscopy (SEM)
of biochar
Courtesy of UK Biochar Research CentreCourtesy of www.carboncommentary.com

20. Scanning slectron micrographs (SEMs) of biochar
derived from (a) corncob, (b) green waste, and © pine
sawdust at 3 magnification (150*,600*,3000*).

21. SEMimagesshowing(a)theexternalsurfaceofafreshchicken
manurebiochar(notethestructureisafunctionofthefeedmaterial);
(b)thesurfaceofthesamebiocharafter1yearinsoil.(Source:
BiocharBESTEnergies;imageEMUUNSW.)

22. X-ray diffraction spectra of 3 biochars compared with synthetic
graphite. Insert shows spectra with expanded vertical scale.

23. Nutrient Content of Biochar
• C-content -75-85% largely unavailable to
decomposition; ∆ microbial activity?
• C/N ratio –12-40 100 lbs biochar has ~8-10 lbs N
protection. Tends to NH4 form.
• P content –0.08%
Other nutrients (S, Mg, Ca, micronutrients)?

24. Some physico-chemical parameters of biochar
Feedstock pH EC(1:5)(dS/m) Ash content (g/kg)
(1:5 H2O)30 min 24h 550
0
C 700
0
C
E. saligna wood7.67+0.100.13+0.010.44+0.01 42+4 37+2
E. saligna leaves9.17+0.051.44+0.233.52+0.15 99+1 40+1
Poultry litter9.20+0.026.32+0.069.27+0.02 423+36 346+1
Cow manure 9.03+0.019.18+0.1412.28+0.19 703+4 704+7
LSD (P=0.05) 0.11 0.29 0.24 36 18

25. Feedstock Total C Total N CaCO
3
P
(g/kg) (g/kg) (mg/kg)
E. saligna wood694.0+5.12.1+0.2 -3.4+0.9 127+8
E. saligna leaves66.8+2.916.4+0.515.4+1.0 2077+51
Poultry litter431.1+6.851.8+0.358.2+2.4 5763+120
Cow manure 175.0+1.513.5+0.134.8+2.1 4359+47
LSD (P=0.05) 6.5 0.3 276

26. Feedstock K S Ca Mg
E. salignawood 1756+200 127+33 17994+590 911+184
E. salignaleaves12816+339 910+22 17144+469 4657+144
Poultry litter24851+1376 4900+455 33352+948 6835+210
Cow manure 26429+3468 4526+75 17518+493 10699+218
LSD (P=0.05) 2380 419 5198 529

27. CEC and exchangeable cationsin biochar
Feedstock CEC
AW
CEC
O
Ca Mg Na K
E. saligna
wood 47.3+47 134.4+3.7 40.1+2.7 1.2+0.2 13.0+0.6 3.3+0.4
E. saligna
leaves 77.7+5.3 71.0+1.3 47.1+2.920.5+0.858.2+0.8 72.2+2.9
Poultry litter172.9+3.7145.1+15.4 28.5+1.346.1+2.9100.1+1.1360.0+12.3
Cow manure 208.8+7.2221.9+5.5 39.9+0.354.0+0.6125.8+1.4475.1+8.3
LSD (P=0.05) 9.3 43 17.9 8.5 3.3 36.1

28. Oxygenated acidic and basic functional groups (mmol
C/g) of biocharsas determined by Boehm titrations
Feedstock Carboxy1 carboxy1 + lactonicTotal acidityTotal basicity
+ phenolic
E. saligna
wood 0.83+0.11 2.68+0.14 5.71+0.76 0.60+0.16
E. saligna
leaves 0.63+0.11 2.67+0.17 5.34+0.73 0.93+0.05
Poultry litter0.83+0.15 3.23+0.14 5.10+0.30 4.29+0.23
Cow manure 2.01+0.24 5.15+0.09 8.08+0.79 6.46+0.27
LSD
(P=0.05) 0.39 0.42 1.52 1.54

29. ElectronmicroprobeelementalmapsonsectionofaGWbiocharparticle
after1yearinsoil.Notethehighconcentrationofmineralsaroundthe
extremityofbiochar(E)andontheflatsurface(F).%TheSEMimageof
theanalyzedareaisalsoshown.(Source:Thebrightertheareathe
highertheconcentration;EMUUNSW.)

30. Characteristics of Biochar
Thepropertiesofbiochargreatlydependupontheproductionprocedure.
TemperatureeffectsonCrecovery,CEC,pHandsurfacearea.
fromLehmann(2007),Front.Ecol.Environ.5:381-387.

31. Schematics for biomass or bio-char remaining after charring
and decomposition in soil. from Lehmann et al., 2006. Mitigation Adap.
Strat. Glob. Change 11: 403–427.
C Sequestration Potential of Biochar
<10-20%

32. •Biochar effects on :
•Soil structure
•Soil aggregate stability
•Soil water
Soil physics

33. Soil physics –soil structure
•↑soilstructureorsoilaerationin
fine-texturedsoils
•biocharhasaveryporousnature
andimprovesoilaggregation
Good structure Poor structure

34. Soil physics –aggregate stability
•↓ the entry of water into the aggregate pores leading to an ↑ in aggregate stability
•hydrophobic polyaromatic backbone ↓ the entry of water into the aggregate pores
leading to an increased aggregate stability and water availability
http://www.landfood.ubc.ca/soil200/interaction/structure.htm

35. Soil physics –soil water
•↑waterretentioninAmazoniancharcoalrich
soils
•formationoforgano-mineralcomplexesby
functionalgroupsofthehumicacids
•increasedaggregatestability–holdswater
•↑moistureinsandysoils–mechanisms?

36. Soil Physics –Research Questions
?
physical characteristics
of biochar on soil
processes -mechanisms
soil workability
mechanisation and application
soil hydrophobicity
physical properties of
biochar change over time
biochar application
influence soil aggregate
stability –link to rates

37. Soil chemistry
•Biochar effects on :
-soil greenhouse gas emissions
-nutrient dynamics –diffuse pollution
(linked to CEC)

38. Biochar and GHG
•N
2OandCH
4-4%and3%respectivelyfromUKagriculture
•ThemajorcontrollingfactorsforN
2Oproductionaretheamounts
ofNH
4
+
,NO
3
-
,water(oxygen),SOM,textureandtemperature
•Biocharencouragesdenitrification:encouragingtheactivityof
enzymesinvolvedinreductionofN
2OtoN
2
•Biochar–highC/Nratio,inducestrongNimmobilisationinitially
•Limingeffectbybiochar–soilpH↑,N
2O↓
•Biochar–CECinfluenceonNH
4
+
andNO
3
-
(precursorstoN
2O
formation)
•Mechanisms–notfullyunderstood

39. Cation Exchange Capacity (CEC)
http://www.spectrumanalytic.com/support/library/ff/CEC_BpH_and_percent_sat.htm
•biochar –↑ surface area, negative surface
charge & charge density
•retains nutrients –link to crop uptake &
diffuse pollution (associated to NVZs)
•better nutrient uptake by crop, ↓ reliance
on manufactured fertilisers
•adsorbs phosphate –mechanism ?

40. Figure 4. Adsorption of phosphate to biochar (produced from
Robinia pseudoacacia L at 350°C for 16 hours). from Lehmann
(2007) Front. Ecol. Environ. 5:381-387.
Adsorption of phosphate to biochar

41. Soil nutrient dynamics
•BiocharhasveryhighC/Nratios(7–400;mean=61)
•CompostwithC/Nratio>25–30:immobilises
inorganicN
•ButbiocharwithhighC/Nratio,mineralisesN,greater
availability(??)
•Dataonavailablenutrientfrombiocharislimited
(N
available=low,P
available=variable,K
available=high)–
dependsonfeedstockandproductioncondition
(Temperature)

42. Diffuse pollution
•Evidencetodatesuggeststhatbiocharapplicationtosoil
willaffectnutrientleachingthroughseveralmechanisms,
-increasingtheretentionofwaterintherootingzone,by
directlybindingorsorbingnutrientsor
-byinteractingwithothersoilconstituents,andby
facilitatingthemovementofattachednutrientswhenfine
biocharparticlesaretransportedinpercolatingwater

43. Soil chemistry –research questions
?
dynamicsofN
2Oemissionfrom
soilsappliedwithbiochar–
(fieldvs.laboratoryscale)–
mechanisms
Nutrientavailabilityand
biochar–C/Nratios–
mechanisms
Catalyst-mineralisationof
nutrientsfromcompost,sewage
sludge
CEC and nutrient (nitrate
and phosphate) retention
Diffusepollution+biochar
–mechanisms(NVZs)

44. Soil biology
•Biochar effects on :
-soil fungal diversity
-soil microbial population

45. Soil biology –fungal diversity
•Biocharinteractionwithmycorrhizal
fungiistheonewhichhasbeenstudiedthe
most
•Mycorrhizaearecommonroot-fungal
mutualisms
•Mycorrhizaecoloniseimportantcrops
(corn,rice,wheat)–agro-ecosystem
productivityandsustainability

46. •Porousnatureofbiochar–adsorptionsitesfor
microbialcommunities(+nutrientsandprotection
frompredators)
•Availabilityofnutrients–linkedtoenzymessecreted
bymicrobialcommunity
•+biochar,↑microbialbiomassbut↓microbialactivity
•(biocharamendments↑thepopulationofmicrobesbut
therateofdegradationofthesubstratesthatareused
bythemicrobesisslowerindicatingthepotential
stabilityandlong-termpersistenceofbiocharinsoil)
Soil biology –microbial population

47. Fig(a)SEMimageshowingclayandsiltparticlesenteringthe
macroresofthegreenwastebiochar.(b)Insideasectionedparticle
(aroundthemiddle)ofgreenwastbiochar.Thelighterareasaround
thebiochararemineralmatterwithvariablecomposition.(Source:
EMUUNSW.)

48. Opticalimageshowingroothairspenetratingabiocharparticlethat
hasbeeninsoilfor20years(sourceN.FoidlfromBoliviansoil).(b)
SEMimageshowingaroothairwithinachickenmanurebiochar
after1yearinsoil.(Source:EMUUNSW.)

49. A spore of arbuscular mycorrhiza extends its hypha into a piece of
porous wood charcoal.(Plate provided by R.Soda.)

50. Soil biology –research questions
?
Biochar-colonising
microorganisms –mechanisms
Bacteria vs. fungi competition
when colonising biochar
surfaces
Fungi influence on altering
soil physiochemical
properties
Indirect effects on
mycorrhizae
through effects on other
soil microbes?

51. Courtesy of Biochar Farming

52. Contaminants(e.g.polycyclicaromatichydrocarbons(PAHs),
heavymetals,dioxins)thatmaybepresentinbiocharmayhave
detrimentaleffectsonsoilpropertiesandfunctions.The
occurrenceofsuchcompoundsinbiocharislikelytoderivefrom
eithercontaminatedfeed-stocksortheuseofprocessing
conditionsthatmayfavourtheirproduction.Evidencesuggests
thatatightcontroloverthetypeoffeedstockusedandlower
pyrolysistemperatures(<500
o
C)maybesufficienttoreducethe
potentialriskforsoilcontamination.
Biocharand potential risk for soil contamination
(Source-BiocharApplicationtoSoilsACriticalScientificReviewofEffectsonSoilProperties,ProcessesandFunctions:F.Verheijen,S.
Jeffery,A.C.Bastos,M.vanderVelde,I.Diafas-EuropeanCommission,JointResearchCentreInstituteforEnvironmentand
Sustainability)

53. •Biocharproducedfromagriculturalcropresidueshasproven
effectiveinsorbingorganiccontaminants.
•Caoetal.(2009)evaluatedtheabilityofdairymanure-derived
biochartosorbheavymetal,Pbandorganiccontaminant,
atrazine.TheyreportedthatsorptionofPbbybiochar
followedadualLangmuir–Langmuirmodel,attributingtoPb
precipitation(84–87%)andsurfacesorption(13–16%).
Biocharand Organic Contaminants
Source:Cao,X.,Ma,L.,Gao,B.andHarris,W.,(2009)Dairy-manurederivedbiochareffectivelysorbsleadandatrazine.
Environ.Sci.Technol.,,43,3285–3291.

54. Health(e.g.dustexposure)andfirehazardsassociatedtothe
production,transport,applicationandstorageofbiocharneedto
beconsideredwhendeterminingthesuitabilityforbiochar
application.Inthecontextofoccupationalhealth,tighthealthand
safetymeasuresneedtobeputinplaceinordertoreducesuch
risks.Someofthesemeasureshavealreadyprovedadequate.
Biocharand Health Hazards
(Source-BiocharApplicationtoSoilsACriticalScientificReviewofEffectsonSoilProperties,ProcessesandFunctions:F.Verheijen,
S.Jeffery,A.C.Bastos,M.vanderVelde,I.Diafas-EuropeanCommission,JointResearchCentreInstituteforEnvironmentand
Sustainability)

55. Inonestudy,biocharadditiontosoilshasbeenshowntoreduce
theemissionofbothCH
4andN
2O.Rondonetal.(2005)reported
thatanearcompletesuppressionofmethaneuponbiochar
additionatanapplicationrateof2%ww
-1
tosoil.Itwas
hypothesizedthatthemechanismleadingtoreducedemissionof
CH
4isincreasedsoilaerationleadingtoareductioninfrequency
andextentofanaerobicconditionsunderwhichmethanogenesis
occurs.
AreductioninN
2Oemissionsof50%insoybeanplantationsand
80%ingrassstandswasalsoreported(Rondonetal.2005).The
authorshypothesizedthatthemechanismleadingtothis
reductioninN
2OemissionswasduetoslowerNcycling,possibly
asaresultofanincreaseintheC:Nratio.
Biocharand CO2, CH4 and N2O Emissions

56. Spokasetal.(2009)comparedCO
2respiration,N
2Oproduction,
methane(CH
4)oxidation,andherbicideretentionand
transformationthroughlaboratoryincubationsatfieldcapacityin
aMinnesotasoil(Waukegansiltloam),withandwithoutadded
biochar.CO
2originatingfromthebiocharwassubtractedfromthe
soil-biocharcombinationinordertoelucidatetheimpactof
biocharonsoilrespiration.Afterthiscorrection,biochar
amendmentreducedCO
2productionforallamendmentlevels
tested(2%,5%,10%,20%,40%and60%w/w;correspondingto
24–720tha
−1
fieldapplicationrates).Inaddition,biocharadditions
suppressedN
2Oproductionatalllevels.However,thesereductions
wereonlysignificantatbiocharamendmentlevels>20%w/w.
Continued----------------
(Source:Spokas,K.A.,Koskinen,W.C.,Baker,J.M.andReicosky,D.C.,(2009)Impactsofwoodchip
biocharadditionsongreenhousegasproductionandsorption/degradationoftwoherbicidesina
Minnesotasoil.Chemosphere,77,574–581.)

57. Conclusions
Soil structure ↑
Soil water ↑ ?
Soil aggregate stability ↑
Soil GHG ↓ ?
Soil nutrient dynamics ↑ ?
Soil fungal diversity ↑
Soil microbial population ↑ ?

58. •Biocharadditioninfluencessoilphysical,chemicaland
biologicalconditionsinmanyways
•Initialworkshowsbestinfluenceofbiocharonlightsoils
•Thereneedstobemoreresearchdonetounderstandthe
mechanismsinvolvedinthebiochar-soilinteractions
•Lowfertilitylightsoilscanbeusedassitesforinitialwork
onbiocharapplicationonafieldscale
•Potentialfeedstockfrommanureandplantsproducedin
theRegionmaybeused
Conclusions

59. •How soil microbial community particularly the soil
heterotrophs will behave under the presence of non-degrading
carbon source?
•Since the decomposition of biochar is extremely slow what
mechanism will be operating for nutrients release/availability?
•What will be the enzymatic activities under the influence of
non degrading substrate like biochar?
•What should be the optimum rate of biochar application?
•What will be the impact of long term application of biochar on
crop yield and soil quality?
•Is there any proven technology for large scale production of
biochar on small farm scale?
Researchable Issues

60. for patient hearing …
AMANWITHA
NEWIDEAISA
CRANKUNTILTHE
IDEASUCCEEDS!