Greenhouse gas emissions and agronomic effects from biochar applications at field scale in

Norway

Adam O’Toole, Hanna Silvennoinen*, and Daniel P. Rasse*presenting authorBioforsk Soil and Environment, Ås, Norway. www.bioforsk.no/biochar adam.otoole@bioforsk.no

Introduction• Biochar-C stability? Is linked to pyrolysis temp.

at which biochar is produced1, however limited field data showing the extent of biochar-C mineralization and effects on native SOM mineralization in ag. soils (eg. Does Priming of SOM occur?)

• GHG impact?: Previous studies2 have shown reductions of N2O in biochar amended fields but no field data show the duration of this effect.

• Agronomy? Meta analyses3 estimate ~10% average yield increases in biochar studies, but little published data avail. for Nordic countries

1Mašek et al. 2011, Fuel. 103: 151-155 2Taghizadeh-Toosi, et al. (2011). JEQ 40(2); Zhang et al.(2012)Fld Crps Res. 127, 153-160 3 Jefferey et al. 2011. Ag. Eco. Env. 144: 175-187

Experiment 1: To estimate the stability of biochar-C under field conditions and BC impact on GHG emissionsExperiment 2: Assess agronomic impacts from biochar application as part of a Northern European ring trial.

Objectives of experiments

Methods for assessing Biochar C stability

• Measuring the δ13C signature and CO2 efflux of a C3 soil after additons of Miscanthus (C4 plant) derived biochar

C4 plants: ~ -15‰

C3 SOM: ~ -30‰

OatsMiscanthus

δ13C

Methods: Experiment 1• GHG measurement: Closed static

chambers, Infrared gas analyzer (IRGA) for CO2 efflux (2 mins per chamber), Piccaro G1101-i for δ13C measurements

• Keeling plot method used to isolate soil respired CO2 in chamber measurements (3, 8, 1440 min).

• Larger closed chambers for N2O, vial measurements taken at 0,15,30, 45 min. and measured via GC

Biochar and Soil description

• Miscanthus giganteus (C4 plant) feedstock• Produced by Pyreg Gmbh (Germany)

Pyroysis temperature 500-750 °C• Fixed C = 70% VM= 7% Ash= 23%• pH: 10• BET: 349 m2 g-1

• Soil: Inceptisol, Sandy Clay Loam, TOC: 2.5 %

Field trials in Norway – 2010-13

Ås (University of Life Sciences, field station)

• Biochar inverse ploughed in the fall of 2010. New application in 2012 (mini plots for N2O study

• Crops – 2011 Oats 2012 Barley 2013 Oats

• Fertilizer: Ammonium Nitrate (NPK 22-3-10, 550 kg ha-1)

Experimental Design• 16 plots (6 x 4 m) / 4 plots (1.5 x 1.5 m miniplots)• 5 treatments x 4 reps• Randomized block design

1. Control – no amendments

2. Straw 8t C ha-1 (2010)

3. Biochar 8 t C ha-1 (2010)

4. Biochar 25 t C ha-1 (2010)

5. Biochar 25 t C ha-1 (New application 2012 for N2O trial) (mini plots)

Air temp and precipitation (Apr-Nov 2012)

Results – Soil respiration

0,000

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0,700

0,800

17.05.2011 06.06.2011 26.06.2011 16.07.2011 05.08.2011 25.08.2011 14.09.2011

g C

O2

m-2

h-1

Soil respiration 2011

Miscanthus 8t C ha-1

Control

Biochar 8t C ha-1

Biochar 25t C ha-1

2011 2012

No significant differences between treatments

Cumulative C loss – 2011-2012

C4 plant-C related loss

  CO2-C loss Contribution to CO2

Contribution to CO2

C loss from straw and biochar

g m-2 g m-2 % %

Control 461 - - -

Straw 8 t C ha-1 467 76 16 9.5%

Biochar 8 t C ha-1 439 5 1 0.6%

Biochar 25 t C daa-1 472 9 2 0.4%

~x 20

Straw and Biochar-C loss after Potassium Dichromate (K2Cr2O7) oxidation(Budai et al. In prep.)

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Straw Bc 250°C BC 300°C BC 500°C Bc 700°C

Field

sit

e c

har~350-450°C threshold for inc. stability

apr mai jun jul aug sep okt

µg

N2O

-N m

-2 h

-1

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200

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1000

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1400

Control BC8 BC25 BC25 new

fertilization harvest

N2O flux 2012

Control BC8 BC25 BC25 new

kg N

2O

-N h

a-1

0

2

4

6

8

10

16.4.- 28.92.5.- 28.9

Cumulative N2O utslipp. 2012 growing season

BiocharClimate Saving Soils project (Interreg IV North sea programme)

17

“To develop, implement and disseminate the biochar-strategy in the North Sea Region (NSR) for climate change adaptation and climate change mitigation by increasing soil quality and stability with soil biochar amendments.”

• 7 countries around the North Sea: UK, NO, SE, DK, DE, NL, BE

• Period 2009-2013

Project objective:

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• Field trial objective: “To test the effect of one wood based biochar on soil quality and crop growth according to a standard protocol, across different soil types and climates of the North Sea Region.”

• Feedstock: mix of Picea abies - Abies alba - Pinus sylvestris -Fagus sylvatica - Quercus robur

• Pyrolysis temperature: 450-480°C

• Dose: 20t/haBiochar characteristics

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• Biochar application date in Norway: spring 2012

• Treatments: 1) biochar, 2) control

• Replicates: 4

• Crop• 2012: spring barley (DE: winter wheat)• 2013: free crop choice

Transnational field trials

Grain yield (Barley) - 2012

Biokull Kontroll0

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500

Bygg

kor

navl

ing

(kg

daa-

1)

Straw yield (Barley) 2012

Biokull Kontroll0

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Bygg

kor

navl

ing

(kg

daa-

1)

Earthworm count in field

biochar control0

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Total Earthworms collected from field site plots2 cores taken from 4 replicate plots per treatment (total 8 cores per treatment)

No.

of e

arth

wor

ms

Bulk density

Experiment 1• Control 1.30 g cm3 ± 0.04• Biochar 8 t 1.16 g cm3 ± 0.11• Straw 8 t 1.19 g cm3 ± 0.07• Biochar 25 t 1.22 g cm3 ± 0.05

Experiment 2• Biochar 1.06 g cm3 ± 0.05• Control 1.17 g cm3 ± 0.09

Conclusion

• Biochar appeared to be Stabil and did not prime native C

• Plant yields similar over all treatments in two wet seasons in a clay loam Norwegian soil

• Reductions in bulk density and increases in worm populations could have a benefits for root growth, but needs more study

Thank you for your attention

Our website: www.bioforsk.no/biochar

Acknowledgements- Raphael Fauches- Monique Carnol, University of Liege- Svend Pung – SKP, UMB- Toril Trædal (UMB)- Christophe Moni, Farshad Tami and Robert Barneveld

Funding: Matprogrammet, Norwegian Research Council. Interreg IV NSR program and SLF