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
Place of origin
Data on Danish import and export of different foodstuffs (www.statistikbanken.dk) used to quantify the proportion
of feed import. The amount of feed imported from different countries was quantified by using FAO
Stat data (www.faostat.fao.org). For calculating the contribution from feed transport the actual place of origin
was used. Whereas, when calculating the contribution from growing the crop, only one place of origin
was included for each crop. For example, growing of soybeans is only based on production conditions in
Brazil.
Feed transport
The inventory data for GHG emission per tkm feed import were taken from LCAFood database (Nielsen et
al., 2003) which are based on ETH data. Data on distances and means of transportation were obtained from
the feed industry and the literature.
Co-product handling – ALCA and allocation
In the calculation based on ALCA, economic allocation was used to distribute the environmental burdens
among co-products. One hectare planted with rapeseed yields 3590 kg, of which 36.4% is extracted as rapeseed
oil and 61.6% as rapeseed cake (Dalgaard et al., 2008). The CF of rapeseed (708 g CO2e/kg) was allocated
by a ratio of 24% to the rapeseed cake and 76% to the oil taking into account the difference in the
prices of the two products (information from FAO). The energy consumption for processing one tonne of
rapeseed was 50 kWh electricity and 340 MJ heat (Dalgaard et al., 2008). Soybeans yield in Brazil is 2544
kg/ha (Ecoinvent, 2010) of which 15.8% is extracted as soy oil and 82.6% as soybean meal (Dalgaard et al.,
2008). The CF of soybean (399 g CO2e /kg) was divided between soybean meal and oil by a ratio of
66.3:33.7. We assumed that the soybean was milled where it was produced. The use of energy for processing
1 kg soybean meal creates 34 g CO2e (Ecoinvent, 2010).
Co-product handling - CLCA and system expansion
When calculating CF of feeds in a consequential approach, it is sufficient to have LCA data on those crops,
whose production is affected by an increased demand for feed (e.g., in the present case the concentrated
feed) in the market. In the CLCA calculation of CF of soybean meal we used system expansion. How an
increased demand for soybean meal affects agricultural production follows the soybean loop suggested by
Dalgaard et al., (2008), where soybean oil is sold on the market and assumed to substitute palm oil, which is
a mix of palm oil and palm kernel oil. As with the ALCA calculation of the CF of soybean meal, the CLCA
calculation was based on data taken from Ecoinvent (2010) on soybean cultivation with the update of emissions
estimate taking into account the 2006 IPCC Guidelines for National Greenhouse Gas Inventories.
The CLCA calculation of CF of rapeseed meal was based on the assumption by Dalgaard et al., (2008) that
an increased demand for rapeseed meal will not affect the production of rapeseed as the rapeseed oil is the
main product, whereas the production of soybean meal and barley will be affected.
Land use chance (LUC)
In the ALCA calculation, GHG emissions from direct LUC (dLUC) were calculated according to PAS2050
(BSI, 2008) on the feeds grown where deforestation takes place. In the present study, only the use of soybean
meal from South America was considered a source of GHG emissions from dLUC. Direct LUC resulting
from the production of soybean meal in Brazil and Argentina would add 7.7 kg and 0.93 kg CO2 per kg soybean
meal, respectively. Import of soybean meal to Denmark is made up of 73% from Argentina and 17%
from Brazil. A weighted average dLUC-GHG emissions rate of 2.0 kg CO2/kg soybean meal was thus calculated.
In the CLCA calculation, GHG emissions from LUC were referred to as indirect use change (iLUC) emissions
calculated according to Audsley et al., (2009) on all feeds. This is essentially based on the assumption
that use of land for crop production would increase pressure on land use and thereby causes LUC somewhere
in the world. From a total LUC-related-GHG emissions of 8.5 GT CO2 per year, the fraction of 58% that
agriculture is responsible for would result in a contribution of 1.43 t CO2/ha/year, taking into account the
total agriculture area of 3,475 Mha (Audsley et al., 2009). In the present study, iLUC was calculated by multiplication
of land use rate (m 2 a/kg feed) by an iLUC-GHG emissions factor of 143 g CO2/m 2 a.
Land use (LU) and soil carbon change
Enhancing carbon (C) sequestration in soil is a way to reduce GHG emissions. However, the size of the sequestration
potential is debatable. In this paper, the effect of changes in soil C was included in a very simple
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