Agriculture Reference
In-Depth Information
Area based GHG emission rates for edible pulses and cereals defi ned by
Dyer et al. [45] were used in Scenario 2 to account for growing annual
crops on
∆
rA. In Scenarios 3 and 4, the emissions to be subtracted from the
initial GHG emission savings come from repopulating
∆
rA with beef cat-
tle. For Scenario 3, the emissions to be subtracted were based on the whole
beef population. For Scenario 4, the emissions to be subtracted were based
on just those parts of the beef population that were not being fattened for
slaughter with feed grain supplements.
6.3 RESULTS AND DISCUSSION
6.3.1 RESULTS
6.3.1.1 CANADIAN LIVESTOCK GHG AND LAND USE
INVENTORY
A summary of GHG emissions from the four livestock industries for eastern
(Atlantic Provinces, Québec, Ontario) and western (Manitoba, Saskatchewan,
Alberta, British Columbia) Canada is shown in Figure 2. These quantities re-
flect the respective sizes of the four industries as much as differences in GHG
emission types. Since changes in soil carbon relate to interactions among live-
stock populations, GHG emissions were grouped in a way that most closely
relates to ruminant and non-ruminant livestock systems. Hence, the GHG
emissions in Figure 2 are distinguished as either enteric or non-enteric. Non-
enteric GHG emissions include manure methane, N
2
O from both the soil and
stored manure, and fossil CO
2
. The main sources of the non-enteric GHGs are
the annual crops that supply the feed grains for non-ruminants (hogs and poul-
try), and the grain component of cattle diets. Canadian livestock accounted
for 53 TgCO
2
e in 2001 with 22 TgCO
2
e coming from enteric methane. The
Canadian beef industry emitted 31 TgCO
2
e. Western beef accounted for 26
TgCO
2
e, 14 of which were enteric methane. Dairy and pork production ac-
counted for 10 and 7 TgCO
2
e, respectively. At 5 TgCO
2
e, poultry was the
lowest source of GHG from the livestock industry in Canada.
