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
Total land use impacts on biodiversity across states, when accounting for all crops, are equal to 1.37
m 2 .yr.PDF/kg milk at the national level. California and Wisconsin contribute to 17% and 15% respectively.
Figure 7. Milk production per state (metric
ton/year)
Figure 8. Land use impacts on biodiversity and contribution
to the milk at the national level production per
state (m 2 .yr.PDF/kg FPCM)
4. Discussion
Land use area requirements, which are mainly driven by the yield, for each crop to be produced in the
feed ration varied up to 6 times from one crop to another. Another key-parameter is the crop production contribution
per state. Results of land use impacts per kg of milk produced from state to state varied up to 15
times for nationally produced crops. A comparison of the results indicate different share of contribution to
the total impacts and for which the crop provenance could be traced back to its production location.
Given the distribution of feed components’ production and their share to the national level production,
states such as California and Wisconsin, which are major contributors to the national milk production require
significant amount of crop to feed cows. However, not being a sizeable in-state corn grain production, they
require a large supply of feed from other states. The latter are located in the Corn Belt region and constitute
the main suppliers’ to many other dairy producers states (i.e. receiver states). Consequently, land use impacts
on biodiversity per kg of milk produced are greater than the ones induced by Minnesota’s milk production,
as it only contributes to 4% of the national milk production. Thus, impacts from an inducer perspective are
larger than those from a receiver perspective. This reasoning applies to feed components, which their supply
mix is assumed to be a national production (eg. commodity crops such as corn grain). For local and not
transportable crops, assumed to be produced within the state where the farm is located, their contribution to
land use impacts of milk production at the national level is mainly local. Thus, induced and received impacts
are equivalent.
As part of the spatial assessment, results for land use impacts on a series of ecosystem services (groundwater
recharge potential, erosion resistance potential, physico-chemical filtration and mechanical filtration
potential) wer also accounted for. Impact results were mainly driven by the milk production fraction at national
scale and thus aligned with the one observed for the biodiversity indicator. California, Wisconsin,
Pennsylvania and New York were consistently among the top contributors to total impact (results not
shown). Detailed results can be foun in the original report (Jolliet et al., 2012).
5. Conclusion
Land use impacts related to milk production across its entire life cycle are mainly driven by land use
needed for feed production, which is required for dairy consumption. The remaining processes beyond the
farm gate contribute to 5% of the total impact to biodiversity (results not shown). These are dominated by
forest land use necessary for pulp production used in manufacturing paperboard cartons and other packaging.
We found that impacts of feed vary significantly depending on the production location. Both inventory
and impact assessment contributes to this variation. Inventory is directly influenced by the yield that determines
the area requirements per unit of crops production. Impact assessment is directly influenced by several
bio-geographic factors, such as climate conditions, vegetation patterns and soil type properties. We
found that spatial differentiation at the state level (the chosen regionalisation scale for this study) is as a key
element when addressing land use impacts. However, future work and improvement could address a finer
and more relevant scale assessment. The latter can be addressed on U.S. ecoregions scale level instead of
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