LCA Food 2012 in Saint Malo, France! - Manifestations et colloques ...

PARALLEL SESSION 7B: BEEF PRODUCTION SYSTEMS 8 th Int. Conference on LCA in the
Agri-Food Sector, 1-4 Oct 2012
Table 2. Effect of stocking on greenhouse gas emissions per kg of beef carcass and per hectare and the
source and percentage of the total contribution to the total greenhouse gas emissions for steer/heifer production
systems
Organic Nitrogen (kg/ha) 150 160 170 180 190 200 210 220
Total emissions per kg beef carcass (kg) 22.2 22.4 22.5 22.6 22.7 22.9 23.0 23.1
Total emissions per hectare (t) 9.2 9.9 10.5 11.2 11.9 12.6 13.3 14.0
Enteric fermentation (%) 48.2 47.9 47.6 47.4 47.2 46.9 46.7 46.5
Manure management (%) 12.6 12.5 12.4 12.4 12.3 12.2 12.2 12.1
Soils (%) 22.6 22.7 22.8 22.9 23.0 23.1 23.2 23.3
Indirect nitrous oxide (%) 4.0 4.0 4.0 3.9 3.9 3.9 3.9 3.9
Diesel use (%) 1.1 1.0 1.0 1.0 0.9 0.9 0.9 0.9
Purchased inputs (%) 11.5 11.9 12.2 12.4 12.6 12.9 13.1 13.3
4. Discussion
In this study, a partial LCA model was developed to evaluate GHG emissions from Irish steer beef production
systems. Ireland exports approximately 90% of its beef output (Breen et al., 2010) and due to the
increased awareness of carbon footprint by society and consumer preference for ‘low carbon-footprint’ food
(Schulte et al., 2011), it is important to quantify the carbon footprint of agricultural products. Nitrous oxide
emissions are generated by the application of organic and inorganic fertilisers and the deposition of faecal
and urine nitrogen by livestock. The quantity of CH4 emissions are determined primarily by the numbers of
livestock and its main source is from animal digestion (enteric fermentation), followed by manure management
where liquid manure storage systems predominate (Crosson et al., 2011). Emissions per kg of beef
carcass in this study were similar to other studies of Irish beef production systems (Casey and Holden, 2006;
Foley et al., 2011). The marginally lower values in the study of Foley et al., (2011) are due to the lower fertiliser
N applied in their study compared to the present study and differences in emission factors applied.
The developed model was applied to examine the effect of stocking rate on greenhouse gas emissions.
Stocking rate is the most important factor affecting production and profitability on farms (Fales et al., 1995;
Crosson and McGee, 2011; Horan et al., 2012). Higher stocking rates due to increased fertiliser N/ha applied
in this study lead to greater GHG emissions. White et al., (2010) reported simalar findings on New Zealand
beef and sheep farms. Neufeldt et al., (2006) found that greenhouse gas emissions on a per hectare basis were
highly correlated (R 2 = 0.85) to the stocking rates on farms in Germany and suggested that stocking rates are
good indicators of overall agricultural GHG emissions. Emissions efficiency in terms of net margin per tonne
of CO2e suggests that there is lower profitability per unit of GHG emission at lower stocking rates.
As a result of EU emissions reductions targets, national governments have must establish respective targets
for their own jurisdictions. However, this analysis has shown that production systems which minimize
emissions on an area and product based basis also result in lower profitability. Furthermore, the analysis has
shown that profitability can be increased substantially by operating at higher stocking rates with only modest
increases in GHG emissions per kg beef carcass albeit with substantial increases in GHG emissions per hectare.
It is apparent that concomitantly achieving GHG efficient and profitable production systems are possible
provided that emissions intensity (GHG emissions per unit product) is the metric used.
5. Conclusion
The developed model is a useful tool in evaluating GHG emissions from beef farms in Ireland This study
shows that increasing stocking rate via increased fertiliser nitrogen application rates and higher grass utilisation
rates lead to increased profitability on beef farms with only modest increases in GHG emissions.
6. References
Baudracco, J., Lopez-Villalobos, N., Romero, L.A., Scandolo, D., Maceil, M., Comeron, E.A., Holmes, C.W. & Barry, T. N. (2011).
Effects of stocking rate on pasture production, milk production and reproduction of supplemented crossbred Holstein-Jersey
dairy cows grazing lucerne pasture. Anim. Feed Sci. and Tech. 168, 131-143.
Breen, J.P., Donnellan, T. & Westhoff, P. (2010). Food for Thought: EU Climate Change Policy Presents New Challenges for Agriculture.
EuroChoices 9, 24-29.
Casey, J.W. and Holden, N.M. (2006). Greenhouse gas emission from conventional, agri-environmental scheme, and organic Irish
suckler-beef units. J. Env. Qual. 35, 231-239.
Crosson, P., O’Kiely, P., O’Mara, F.P. & Wallace, M. (2006). The development of a mathematical model to investigate Irish beef
production systems. Agric. Sys. 89, 349-370.
Crosson, P. (2008). The impact of cow genotype on the profitability of grassland-based suckler beef production in Ireland. In: Proceedings
of the 22 nd Annual Meeting of the European Grassland Federation, Uppsala, Sweden, 9-12 June, p 771.
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