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

Adam O’Toole, Hanna Silvennoinen*, and Daniel P. Rasse * presenting author

Bioforsk Soil and Environment, Ås, Norway. www.bioforsk.no/biochar [email protected]

Introduction

• Biochar-C stability? Is linked to pyrolysis temp. at which biochar is produced 1 , 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 studies 2 have shown reductions of N 2 O in biochar amended fields but no field data show the duration of this effect. • Agronomy? Meta analyses 3 estimate ~10% average yield increases in biochar studies, but little published data avail. for Nordic countries 1 Mašek et al. 2011, Fuel. 103: 151-155 2 Taghizadeh-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

Objectives of experiments

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

Methods for assessing Biochar C stability

• Measuring the δ 13 C signature and CO 2 efflux of a C3 soil after additons of Miscanthus (C4 plant) derived biochar C4 plants: ~ 15‰ δ 13 C Miscanthus Oats C3 SOM: ~ 30‰

Methods: Experiment 1

• GHG measurement: Closed static chambers, Infrared gas analyzer (IRGA) for CO 2 efflux (2 mins per chamber), Piccaro G1101-i for δ 13 C measurements • Keeling plot method used to isolate soil respired CO 2 in chamber measurements (3, 8, 1440 min).

• Larger closed chambers for N min. and measured via GC 2 O, vial measurements taken at 0,15,30, 45

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 m 2 g -1 • Soil: Inceptisol, Sandy Clay Loam, TOC: 2.5 %

Field trials in Norway – 2010-13

• Biochar inverse ploughed in the fall of 2010. New application in 2012 (mini plots for N 2 O study • Crops – 2011 Oats 2012 Barley 2013 Oats • Fertilizer: Ammonium Nitrate (NPK 22-3-10, 550 kg ha -1) Ås (University of Life Sciences, field station)

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 N 2 O trial) (mini plots)

Air temp and precipitation

(Apr-Nov 2012)

Results – Soil respiration

2011

Soil respiration 2011

0,800 0,700 0,600 0,500 0,400 0,300 0,200 0,100 0,000 17.05.2011

06.06.2011

26.06.2011

16.07.2011

05.08.2011

25.08.2011

14.09.2011

Miscanthus 8t C ha-1 Control Biochar 8t C ha-1 Biochar 25t C ha-1 2012 No significant differences between treatments

Cumulative C loss – 2011-2012

C4 plant-C related loss

Control Straw 8 t C ha -1 Biochar 8 t C ha -1 Biochar 25 t C daa -1 CO 2 -C loss Contribution to CO 2 Contribution to CO 2 g m -2 461 467 439 472 g m -2 76 5 9

%

16 1 2 C loss from straw and biochar

%

9.5% ~x 20 0.6% 0.4%

Straw and Biochar-C loss

after Potassium Dichromate (K 2 Cr 2 O 7 ) oxidation (Budai et al. In prep.) 100% ~350-450 ° C threshold for inc. stability 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% Straw Bc 250 ° C BC 300 ° C BC 500 ° C Bc 700 ° C

N

2

O flux 2012

fertilization harvest 1400 1200 1000 800 600 400 200 Control BC8 BC25 BC25 new 0 apr mai jun jul aug sep okt

4 2 0 6 8 10

Cumulative N

2

O utslipp.

2012 growing season 16.4.- 28.9

2.5.- 28.9 Control BC8 BC25 BC25 new

BiocharClimate Saving Soils project (Interreg IV North sea programme)

Project objective: “

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 17

• 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 sylvatica

-

Quercus robur

-

Abies alba

-

Pinus sylvestris

-

Fagus

• Pyrolysis temperature: 450-480 ° C • Dose: 20t/ha Biochar characteristics 18

Transnational field trials • 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 19

Grain yield (Barley) - 2012

500 450 400 350 300 250 200 150 100 50 0

Biokull Kontroll

Straw yield (Barley) 2012

250 200 150 100 50 0

Biokull Kontroll

Earthworm count in field

30 20 10 0 80 70 60 50 40 biochar control

Total Earthworms collected from field site plots 2 cores taken from 4 replicate plots per treatment (total 8 cores per treatment)

Bulk density

Experiment 1 • Control 1.30 g cm 3 • Biochar 8 t 1.16 g cm 3 • Straw 8 t 1.19 g cm 3 • Biochar 25 t 1.22 g cm 3 Experiment 2 • Biochar • Control 1.06 g cm 3 1.17 g cm 3 ± 0.04

± ± 0.11

0.07

± 0.05

± 0.05

± 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

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 Our website: www.bioforsk.no/biochar