April 28, 2021
Methane (CH4) – Generated by ruminants as a by-product of digestion.
Most CH4 is burped into the atmosphere by ruminant livestock. A small amount of CH4 (less than 5%) also comes from dung and effluent systems. The total feed eaten by livestock on your farm (per kilogram of dry matter intake) is the driver of CH4 emissions.
Nitrous Oxide (N2O) – Released into the atmosphere from dung and urine patches, and N fertilisers. The nitrogen content of feed and the amount of nitrogen applied are the main drivers of N2O emissions, temperature and soil moisture can also play a role.
Carbon Dioxide (CO2) – The main driver of net farm CO2 emissions is the area of woody vegetation. Woody vegetation captures CO2 but also releases it when cleared. To a much lesser extent the application of lime and urea nitrogen (N) fertilisers can also contribute to farm CO2 emissions. Soil management can both release and sequester CO2 and this is under investigation so it can be better quantified.
Energy use is the other driver of farm CO2 emissions. As it is already accounted for under the New Zealand Emissions Trading Scheme it is not included in your farm greenhouse gas emissions. However, it should be considered when assessing the costs and benefits of reduction opportunities, and to calculate your carbon footprint.
Want to know more?
The AgMatters website is a valuable source of information on farm greenhouse gas emissions www.agmatters.nz
Talk to your sector organisation or an experienced rural professional for more detailed farm greenhouse gas emissions information.