Agriculture Reference
In-Depth Information
did not consider inter-commodity interactions. Satisfying livestock diet re-
quirements can lead to competition for feed grain, especially under inten-
sive animal production. Since livestock industries must share arable land
with food crops, oilseeds [6] and biofuel feedstock crops [5,17], livestock
industries can no longer be treated as separate closed systems. The Unified
Livestock Industry and Crop Emissions Estimation System (ULICEES)
was created by assembling the four sets of livestock GHG computations in
one model. ULICEES also takes the changes in the soil carbon stock into
account. Although ULICEES is applicable to any agricultural census year,
in this analysis it was applied to 2001, the most recent year for which the
livestock diet survey data was available [18].
Figure 1 presents the generalized computational fl ow of the set of cal-
culations for quantifying the GHG emission budgets for Canadian live-
stock production. Only the functions common among all four livestock
industries are illustrated. The yields, areas, and fertilizer application rates
for each crop and population for each livestock type are shown as com-
putational inputs. The resulting GHG emission categories and totals are
shown at the bottom of the chart. Although ULICEES addresses the ques-
tion of how to measure the carbon footprint of all food of animal origin in
Canada [8], this chart does not show interactions among commodities and
it only considers changes in soil CO
2
emissions under a land use change.
All of the GHGs associated with animal housing [19] were also taken into
account in ULICEES.
6.2.1.2 CROP COMPLEX
The scope of assessment adopted by Vergé et al. [14] included the associ-
ated complex of crops that supported each commodity production system.
The carbon footprint of animal based production cannot be effectively
quantified without first determining the GHG emissions from growing the
feed grains and the forage they consume. That land base, defined as the
livestock crop complex (LCC), was the result of integrating the diets of all
the age-gender categories in each livestock type over the whole popula-
tion. Each crop component of each diet was divided by the average yield
of that crop to estimate the land required to grow the crop.
