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

PARALLEL SESSION 2A: LAND USE 8 th Int. Conference on LCA in the
Agri-Food Sector, 1-4 Oct 2012
gas grids in the system description, investment costs for building a local biogas grid were included in the
analysis.
Production of bioenergy can be in conflict with the production of food, since land and water resources are
limited. In life cycle assessment, as well in the bioenergy debate at large, this has been referred to as “indirect
land use change”, an aspect that has traditionally not been included in LCA of agricultural products and
systems, but in some recent attempts indirect land use change has been included. In this work, we have
avoided this issue by only using agricultural residues as biomass sources for bioenergy, and thus not reducing
the amount of land available for food production at all. We have not considered any effects on farm
yields by these modifications. For example, it is plausible that yields can be increased by producing biogas
from ley and optimizing the application of digestate, as compared to ploughing down the yield. Another case
is when straw s removed and soil carbon content is reduced, which could result in reduced soil fertility and
lower yields.
6. Conclusions
Swedish milk production can become self-sufficient in energy by utilizing renewable sources available on
the farm, and thereby reduce GHG emission from production of 1 kg of ECM by 29-44% compared with a
conventional farm system. The highest GHG emission reductions were found in a system where energy was
supplied only with biogas, while a system with RME was least favourable.
The arable organic farm studied could be self-sufficient in energy by using the residues available in the
crop rotation: using ley for biogas production or straw for ethanol, heat and power production. Because of
due to soil carbon losses the greenhouse gas emission savings are lower with the straw system (9%) than the
ley system (35%).
7. Acknowledgements
The research was funded by FORMAS, the Swedish Research Council for Environment, Agricultural Sciences
and Spatial Planning.
8. References
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