1) Switching to biomass production for energy can enhance carbon sequestration by removing CO2 from the atmosphere and displacing emissions from fossil fuels. 2) Measurements show that perennial biomass crops like miscanthus have high biomass productivity and carbon uptake in soils, with potential to sequester 1-5 tons of CO2 per hectare annually. 3) Models were able to reasonably predict measurements of variables like net primary productivity, soil carbon, and nitrous oxide emissions across different land uses including arable, pasture, and biomass crops.

1. Emissions from biomass production
Gary J. Lanigan

2. Caroline Narayan1, Órlaith Ní Chonchubair1,2, Dominika
Krol 1,3
John Clifton-Brown, Marta Dondini3, Karl Richards1,
John Finnan, Bruce Osborne2, Mike Jones3, Chris
Mueller2, Mike Williams3
Saul Otero2, Matt Saunders2, Wanne Kromdijk4,
Howard Griffiths4, Astley Hastings5, Pete Smith5
1 Teagasc, Johnstown Castle Environmental Research Centre, Wexford
2 School of Biological & Environmental Science, UCD, Dublin 4
3 School of Natural Sciences, Trinity College, Dublin 2
4 Department of Plant Sciences, Cambridge University, CB2 3EA
5 Department of Soils & Global Change, Aberdeen University
Funding
RSF 06 403, RSF 07 528 & RSF 07 527

3. Outline
• Policy Context
• Shifting to Biomass – Measurements
• Change in emissions associated with
LUC
• Conclusions

4. Future challenges
• Post Kyoto –
–20% from the non-ETS sectors without a
global agreement
–30% with an agreement
• Agriculture will come under sustained
pressure to reduce emissions in the
medium term
• Impetus for increased production
• NZ/Australia are placing agriculture
within national ETS

5. Shifting to biomass production
• Enhanced Carbon sequestration – direct
removal of CO2 from the atmosphere
• Displacement of N2O emissions
• Substitution of fossil fuel emissions

6. Components of the agricultural C budget
NBP: Biome Productivity, Soil C balance
NEE: Net Ecosystem Exchange, Atmospheric C balance
NBP
NEP
NPP
GPP
Photosynthesis Autotrophic Heterotrophic Cuts Manure
respiration respiration

10. Ecosystem fluxes – Eddy covariance

11. Soil respiration

12. Pasture Net C Balance
Loss
40
20
C flux (gC m-2)
0
0 10 20 30 40 50 60
-20
-40
-60
-80
Uptake

13. Pasture/Maize Net C Balance
40
C flux (gC m-2)
20
0
0 10 20 30 40 50 60
-20
-40
-60
-80

14. Pasture/OSR Net C Balance
40
C flux (gC m-2)
20
0
0 10 20 30 40 50 60
-20
-40
-60
-80

15. Pasture/Maize/Miscanthus Net C Balance
40
C flux (gC m-2)
20
0
0 10 20 30 40 50 60
-20
-40
-60
-80
Miscanthus has a long growing season and little
disturbance

16. Potential Biomass Production
14
12
Biomass (t ha-1)
10
8
6
4 Miscanthus
2
SRC
0
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21
Year

17. = (a x b)/(b + PFD)

18. Modelled GPP using isotopic models

19. Quality as well as quantity: The ultimate fate of SOC
Particulate SOC (tC ha-1)
25
20
15
10 New C
5
0 Old C
Barley Maize Miscanthus Barley Maize Miscanthus

20. Dondini et al 2009 GCB-Bioenergy

22. NPP
Soil C
Trace gases

23. 10
9 Measured
8 Modelled
NPP (t C ha-1)
7
6
5
4
3
2
1
0
Maize Maize OSR (2008) Miscanthus Grassland RCG
(2008) (2009)

24. 160
Measured
140
Soil Carbon (t C ha-1)
Modelled
120
100
80
60
40
20
0
Grass (JC) Maize (4 yrs Grass (OP) Arable Miscanthus
LUC)

25. Modelled vs Measured N2O
emissions
8
Modelled N2O (kg N2O-N ha-1 yr-1)
6
Arable
4
Pasture
2
0
0 2 4 6 8
Measured N2O (kg N2O-N ha-1 yr-1)

26. 100
80
Modelled
60
Poorly –drained
40
Loam/clay
20
R2 = 0.34
0
0 10 20 30 40 50 60 70 80
Measured
120
100
80
Modelled
60
R2 = 0.44
40
20
Moderate –drained
0 Loam
0 10 20 30 40 50 60 70 80
Measured

27. Requirements
• Soils characteristics including bulk
density and C stocks
• A soils map and a land-use tracking
system
• Spatially integrated measurements of
N2O in grazed pasture systems
• Ground-truthing across a range of soil
types and land-uses

28. Conclusions
• Sequestration potential of perennial biomass
crops could be high: 1-5 tCO2 ha-1 a-1
• SOC loss due to ploughing of pasture NOT as
high as defaults
• 30% Co-firing Target: Replacement of ~0.91
million tonnes of peat = 0.85 Mt CO2-eq –
Heat Production C savings potentially even
greater (+1.5 million tonnes)
• Who gets the credits?