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 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

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 δ13C signature and CO2 efflux of a C3 soil after additons of Miscanthus (C4 plant) derived biochar C4 plants: ~ -15‰ δ13C Miscanthus Oats C3 SOM: ~ -30‰

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 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) 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 Control – no amendments Straw 8t C ha-1 (2010) Biochar 8 t C ha-1 (2010) 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 2011 2012 No significant differences between treatments

Contribution to CO2 flux Cumulative C loss – 2011-2012 C4 plant-C related loss   CO2-C loss Contribution to CO2 C loss from straw and biochar 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 Table 1. Degradation of C4 products and contribution to Soil-C flux (2011-2012)   C4 related loss CO2-C loss amount Contribution to CO2 flux loss of C4 inputs g m-2 % Control 461 - Miscanthus 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 ha-1 472 9 2 0.4%

Straw and Biochar-C loss after Potassium Dichromate (K2Cr2O7) oxidation (Budai et al. In prep.) ~350-450°C threshold for inc. stability Field site char Straw Bc 250°C BC 300°C BC 500°C Bc 700°C

N2O flux 2012 fertilization harvest

Cumulative N2O utslipp. 2012 growing season

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

Biochar characteristics 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/ha Biochar characteristics Biochar characteristics

Biochar characteristics 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 Biochar characteristics

Grain yield (Barley) - 2012

Straw yield (Barley) 2012

Earthworm count in field

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 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