livestock related nitrous oxide emissions are estimated to total
between 1 and 2 million tonnes of nitrous oxide-N each year. Livestock
themselves produce only relatively minor amounts of nitrous oxide
Though some nitrous oxide can be produced in ruminant guts via
the reduction of nitrate in livestock feed to ammonia and ammonium,
the very anoxic conditions in the gut mean that actual nitrous
oxide production is likely to be very low.
Where livestock do have a large impact on nitrous oxide emissions
is through initial production of their feed, and through subsequent
management of their waste. Livestock feed production, like human
food production, often involves large applications of nitrogen
based fertilizer to agricultural soils. This in-turn results in
nitrification and denitrification in the soil and the release
of nitrous oxide to the atmosphere.
Nitrous oxide arises from animal wastes occurs during both storage
and treatment, again by the processes of nitrification and denitrification.
Additionally, nitrous oxide is indirectly produced via the volatilization
and atmospheric oxidation or deposition
of nitrogenous compounds, such as ammonia and nitrogen oxides.
As humans are directly responsible for livestock rearing, we
are also responsible for livestock related nitrous oxide production.
Increased global demand for meat and diary products has led to
increases in animal wastes. Additionally, the more intensive livestock
rearing practices now common throughout the world have necessitated
more intensive livestock feed cultivation, with the inevitable
increase in N fertilizer use and nitrous oxide emissions.
Potential for control
The demand for livestock feed with a high nitrogen content makes
the potential for reductions in livestock related emissions through
feed cultivation practices limited. As with agriculture as a whole,
better targeted fertilizer application and properly informed land-use
practice may go some way to reducing nitrous oxide emissions from
The various livestock waste management strategies provide further
ways in which emissions can be reduced. The use of subsurface
injection of liquid waste for instance can result in a much lower
emission of nitrous oxide than that from its surface application
to open pasture.