Opportunities for Carbon Sequestration in Irish Grasslands

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Opportunities for Carbon Sequestration in Irish
Grasslands

• Vesna Jakšic
• Supervisors G. Kiely, University College Cork
• O. Carton, D.Fay, Johnstown
  Castle

Dublin, 20/11/2003
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Why study atmosphere Carbon Dioxide ?
Opportunities for Carbon Sequestration in Irish
Grasslands

• The Kyoto Protocol for Ireland requires that
  emissions of GHG must be no more than 13 above
  the 1990 levels
• As of 2001, emissions are 31 greater than the
  1990 levels (EPA)
• By 2008 2012 the business as usual scenario
  forecast (produced in 2000 based on 1998 data) is
  that emissions may be more than 37 greater than
  the 1990 levels (NCCS)
• Agricultural is responsible for about 27 (soils
  5.5) in 2001 of emission (EPA)

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Question ?
Opportunities for Carbon Sequestration in Irish
Grasslands
Are agricultural soils sources or sinks for
carbon ?
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Budget of Carbon for a farm
Opportunities for Carbon Sequestration in Irish
Grasslands

• NEE (A B C) Csoil
• NEE Net Ecosystem exchange in T of C/ha
• NEE GPP Rh Ra
• A, B, C carbon leaving the farm
• (in milk, in meat, in enteric
  fermentation etc.)
• Csoil the carbon fixed to the soil
• or lost to the atmosphere?

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Objectives of project
Opportunities for Carbon Sequestration in Irish
Grasslands

• Measure and model the CO2 flux at grasslands in
  Dripsey (Cork) and Johnstown Castle (Wexford)
• Investigate seasonal, annual and interannual
  fluxes
• Estimate the carbon budget at farm scale and so
  determine if the soils are sinks or sources of
  carbon

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Sites
Opportunities for Carbon Sequestration in Irish
Grasslands
Cork grassland Dripsey Elevation
190masl Annual rainfall 1450mm
Wind Rose Downwind direction is SW
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NEE Eddy Covariance System
Opportunities for Carbon Sequestration in Irish
Grasslands
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Eddy Covariance
Opportunities for Carbon Sequestration in Irish
Grasslands
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Footprint area
Opportunities for Carbon Sequestration in Irish
Grasslands
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CO2 flux measurements
Opportunities for Carbon Sequestration in Irish
Grasslands

• July 2001 to Jun 2003 (the results for 24
  months)

• The site is intensive cattle grassland
  (Livestock density 2.2 LU/ha) with mix of grazing
  and silage

• Nitrogen in chemical fertilizer was applied at
  the rate of 190kgN/ha and N in slurry
  approximately 90kgN/ha for the year 2002

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Raw CO2 flux data _at_ 30 minute intervals
Opportunities for Carbon Sequestration in Irish
Grasslands
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CO2 flux and soil moisture
Opportunities for Carbon Sequestration in Irish
Grasslands
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Cumulative uptake T Carbon/ha
Opportunities for Carbon Sequestration in Irish
Grasslands
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Cumulative uptake T Carbon/ha
Opportunities for Carbon Sequestration in Irish
Grasslands
Year 2002
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Some NEE values
Opportunities for Carbon Sequestration in Irish
Grasslands
location Type of land NEE T of C/ha.yr
1 Duke, US Loblolly pine forest 5.7 to 7.9
2 Mandan, US Native prairie 0.6 to 0.9
3 Woodward, US Plain prairie -0.2 to 1.8
4 Temple, US Mixed-grass prairie 2.2 to 7.7
5 Ottawa, Canada Bog peatland 0.5 to 0.9
6 Cork, Ireland Perennial ryegrass pasture 2.2 to 3.7
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Carbon leaving the farm
Opportunities for Carbon Sequestration in Irish
Grasslands

• Carbon in milk t.C/ha.yr.
• average production 7500L/ha.
• density f 1.03kg/L
• carbon in milk 4.5

CA 0.35 T.C/ha.

• Carbon in meat t.C/ha.yr.
• 18 of live weight
• 1LU 520kg pasture dry matter per year
• Stocking Density for Dripsey 2.2LU/ha
• Assume that 1/3 of animals leave farm for
  the meat factory

CB 0.1 T.C/ha
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Carbon leaving the farm
Opportunities for Carbon Sequestration in Irish
Grasslands

• Carbon in CH4 respired from animal and CH4 from
  manure for full year
• 100kg CH4 from animal
• 15kg CH4 from manure
• Stocking Density for Dripsey 2.2LU/ha
  

CC 0.20T.C/ha.

• Carbon as CO2 from respiring animal indoors for 4
  months of year
• Diet 10kgDM/day/LU
• DM 45Carbon
• Assume 40 respire

CD 0.45 T.C/ha
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Carbon Budget
Opportunities for Carbon Sequestration in Irish
Grasslands
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Conclusions
Opportunities for Carbon Sequestration in Irish
Grasslands

• For 8 months (Mar to Oct) the site is a sink of
  carbon

• Interannual variability of NEE is significant
• (2.2 to 3.7 T of C/ha.yr) need long term
  measurements

• Preliminary results carbon sequestration for
  2002
• at Cork site is 1.2 T of C/ha.yr (forestry 3 to 6
  T of C/ha)

• Preliminary results suggest that there may be
  opportunities for Carbon sequestration in
  grassland soils

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Acknowledgements
Opportunities for Carbon Sequestration in Irish
Grasslands

• Teagasc Walsh Fellowship Programme

• Environmental Protection Agency

• O. Carton and D. Fay, Environment and Land
  Use Department Teagasc Johnstown Castle
• G. Kiely, University College Cork