1. UCC Opportunities for Carbon Sequestration in Irish Grasslands Vesna Jakši ć Supervisors: G. Kiely, University College Cork O. Carton, D.Fay, Johnstown Castle Dublin, 20/11/2003

2. UCC Why study atmosphere Carbon Dioxide ? 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) Opportunities for Carbon Sequestration in Irish Grasslands

3. UCC Question ? Opportunities for Carbon Sequestration in Irish Grasslands Are agricultural soils sources or sinks for carbon ? Air Soil Source Sink C sequestration

4. UCC Budget of Carbon for a farm NEE – (A + B + C+…) = C soil 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.) C soil = the carbon fixed to the soil or lost to the atmosphere? or lost to the atmosphere? Opportunities for Carbon Sequestration in Irish Grasslands

5. UCC Objectives of project Measure and model the CO 2 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 Opportunities for Carbon Sequestration in Irish Grasslands

6. UCC Sites Wind Rose Downwind direction is SW Cork grassland – Dripsey Elevation ~ 190masl Annual rainfall ~ 1450mm Opportunities for Carbon Sequestration in Irish Grasslands red dots ↔ site areas

7. UCC NEE – Eddy Covariance System Opportunities for Carbon Sequestration in Irish Grasslands Rain gauge Temperature and relative humidity probes at 3m Perimeter for soil moisture, soil temperature and soil heat flux probes The automatic weather station– tower in full height Sonic anemometer Net radiometer LICOR H 2 O/CO 2 sensor LICOR electronics box Top of the tower with instruments

8. UCC Eddy Covariance Opportunities for Carbon Sequestration in Irish Grasslands Sonic anemometer LI-7500 Open Path CO 2 /H 2 O gas analyser

9. UCC Footprint area Opportunities for Carbon Sequestration in Irish Grasslands Estimated footprint N

10. UCC CO 2 flux measurements July 2001 to Jun 2003 (the results for 24 months) Nitrogen in chemical fertilizer was applied at the rate of 190kgN/ha and N in slurry approximately 90kgN/ha for the year 2002 The site is intensive cattle grassland (Livestock density 2.2 LU/ha) with mix of grazing and silage Opportunities for Carbon Sequestration in Irish Grasslands

11. UCC August 2002 Net Photosynthesis Net Respiration Raw CO 2 flux data @ 30 minute intervals Opportunities for Carbon Sequestration in Irish Grasslands

12. UCC CO 2 flux and soil moisture Opportunities for Carbon Sequestration in Irish Grasslands SINK SOURCE Soil porosity 48%

13. UCC Cumulative uptake T Carbon/ha Opportunities for Carbon Sequestration in Irish Grasslands

14. UCC Cumulative uptake T Carbon/ha Year 2002 Opportunities for Carbon Sequestration in Irish Grasslands

15. UCC Some NEE values locationType of land NEE [T of C/ha.yr] 1Duke, USLoblolly pine forest5.7 to 7.9 2Mandan, USNative prairie0.6 to 0.9 3Woodward, USPlain prairie-0.2 to 1.8 4Temple, USMixed-grass prairie2.2 to 7.7 5Ottawa, CanadaBog peatland0.5 to 0.9 6Cork, IrelandPerennial ryegrass pasture2.2 to 3.7 Opportunities for Carbon Sequestration in Irish Grasslands

16. UCC Carbon leaving the farm Opportunities for Carbon Sequestration in Irish Grasslands A.Carbon in milk [t.C/ha.yr.] average production 7500L/ha. density φ = 1.03kg/L carbon in milk = 4.5% C A = 0.35 T.C/ha. B.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 C B ≈ 0.1 T.C/ha

17. UCC Carbon leaving the farm Opportunities for Carbon Sequestration in Irish Grasslands C.Carbon in CH 4 respired from animal and CH 4 from manure for full year 100kg CH 4 from animal 15kg CH 4 from manure Stocking Density for Dripsey = 2.2LU/ha C C = 0.20T.C/ha. D.Carbon as CO 2 from respiring animal indoors for 4 months of year Diet = 10kgDM/day/LU DM = 45%Carbon Assume 40% respire C D = 0.45 T.C/ha

18. UCC Carbon Budget CO 2 Net Ecosystem Exchange NEE -2.5 T.C/ha/yr Atmosphere Canopy C as DOC/DIC in stream +0.1 T.C/ha/yr C as CH 4 from yard manure / slurry +0.1 T.C/ha/yr C as CO 2 from respiring animal indoors for 4 months of year +0.45 T.C/ha/yr C in milk export +0.35 T.C/ha/yr C in meat export +0.1 T.C/ha/yr C as CH 4 from animal +0.2 T.C/ha/yr Soil Soil Sequestration -1.2 T.C/ha/yr Opportunities for Carbon Sequestration in Irish Grasslands

19. UCC 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 1.2 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

20. UCC Acknowledgements Environmental Protection Agency Teagasc Walsh Fellowship Programme O. Carton and D. Fay, Environment and Land Use Department Teagasc Johnstown Castle G. Kiely, University College Cork Opportunities for Carbon Sequestration in Irish Grasslands