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

PARALLEL SESSION 4C: CROP PRODUCTION SYSTEMS 8 th Int. Conference on LCA in the
Agri-Food Sector, 1-4 Oct 2012
2.3 Calculation of particular fluxes and of freshwater Ecotoxicity
N2O, NO, NH3 NO3- and P2O5 emissions are fluxes that need particular calculation because they depend
both on agricultural practices and on pedoclimatic and agronomic conditions. Their calculation requires the
use of models, as reliable and recognized as possible.
Direct and indirect emissions of N2O and NO were assessed for each field separately, using the
Bouwman emission factors (Bouwman et al., 2002). The calculation of NH3 emissions were made with the
Ges’tim (Institut de l’élevage et al., 2002) and Corpen (2006) methods. The NO3- emissions were estimated
thanks to a calculation tool integrated into Epicles (one of InVivo’s decision-making tools) which uses the
Burns model (1976) to determine the part of nitrogen that is leachable during winter rainfalls. For the P2O5
emissions, the SALCA-P method was used (Prasuhn 2006 and Nemecek et al., 2007).
The freshwater ecotoxicity impacts of pesticide applications were assessed for each field separately, using
characterisation factors (CF) from USEtox (Rosenbaum et al., 2008) in line with the method previously used
in a published study by Berthoud et al., (2011).
2.4 Characterisation
A tool developed on Microsoft’s Excel by Bio Intelligence Service was used to make the characterisation
calculations, in compliance with several characterisation methods, depending on the LCA indicator.
The global warming impacts of the inventoried fluxes were assessed with the IPCC method. The RECIPE
method was used to characterise the fluxes respectively relevant to freshwater and marine eutrophication,
and terrestrial acidification. Water depletion and non-renewable energy indicators were calculated according
to a simple fluxes assessment. As for freshwater ecotoxicity impacts, they were assessed thanks to the USEtox
method, as detailed in the previous paragraph.
3. Results
3.1. Environmental impact of winter wheat
Figure 5. Contribution of the several stages of the wheat life cycle to the LCA indicators results & Mean
values of each LCA indicator for the different cooperatives involved in the study
The results show that the most impacting stages of wheat production on greenhouse gases emissions, marine
eutrophication, terrestrial acidification and energy consumption are quite the same: nitrogenous fertilisers’
production, transport and application on the field. This can be explained by the important emissions and
energy consumption during the production of mineral fertilisers, as well as by the in-field emissions (N2O,
NO3 and NH3), which are linked to the application of both mineral and organic fertilisers. Farm machinery
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