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

PARALLEL SESSION 3C: SHEEP AND DAIRY PRODUCTION SYSTEMS 8 th Int. Conference on LCA in the
Agri-Food Sector, 1-4 Oct 2012
3. Results
The average footprint of 1 kg of Canadian FPCM was calculated for each province using provincial averages
of inventory flows and provincial weighted averages of characterisation factors based on farm locations
and their production.
Table 2. Sources of impact and allocated profile
Damage Indicator Main Contributor Value Unit
Climate Change
Ecosystem Quality
Enteric fermentation, feed production, manure
Land use, phosphorus eutrophication, emissions from coal for
1.01
14.95
kg CO2e
PDF.m 2 .yr
power, where applicable
Human Health NH3 emissions (land use), NOx, SO2 (energy & diesel) 8.3e-7 DALY
Resource Depletion Feed production, energy on farm, transportation 3.98 MJ
Water Consumption Irrigation (when applicable), evaporation in energy production 61 L
3.1. Climate change
The distribution of greenhouse gas emissions (Fig. 2) was similar to that of other studies. While energy,
transportation and buildings and equipment had little impact (8% of the total), the most important emissions
were caused by CH4 and N2O emissions, occurring, in decreasing order, from enteric fermentation, manure
storage and feed production.
Figure 2. Distribution of average greenhouse gas emissions per kg of fat-and-protein-corrected milk (FPCM)
across life cycle steps, with spread of provincial average results (error bars).
Variability in provincial results were highest (0.025-0.17 kg CO2e/kg FPCM) for energy emissions, due
to the variability of the electrical-grid-mix among provinces (14-293 g CO2e/kWh). Variability was likely
underestimated in feed production, due to the assumption that fertilisation recommendations were always
followed. Still, based on soils and crops, manure spreading practices varied among provinces, while emission
factors also varied based on geography, a result mostly linked to humidity (Rochette et al., 2008). Feedproduction
emissions were lowest in Alberta and Saskatchewan, because of their dry climate, while they
were highest in British Columbia, due to a moist climate and high N recommendations for hay (200-300 kg
N/ha, compared to less than 150 kg/ha elsewhere), followed by the Atlantic provinces, also because of moist
climates, average yields and lower milk production per animal.
Variability in emissions from livestock management were linked to changing replacement-animal ratios
(since their feed, digestion and manure is also included in the milk production system), as well as digestibility
of feed, with concentrates, for example, having higher digestibility than forage. Finally, different types of
manure storage contributed to variability in manure-management emissions.
3.2. Water footprint
Water use was influenced by two distinct scenarios: irrigated crops in western Canada and non-irrigated
crops elsewhere. Water withdrawal, based on low-resolution statistics, reached 550 L/kg FPCM in the worstcase
scenario (highest provincial irrigation per hectare) but was as low as 29 L/kg FPCM elsewhere. In terms
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