Greenhouse gases are an important loss pathway for nutrients from farm systems. In addition to the benefits which may occur from individual farms looking at reducing nutrients and energy lost through this pathway New Zealand is committed to reduce agricultural GHG emissions and building the agricultural sector’s resilience to climate change.
OverseerFM is one of the tools that can be used by farmers to help understand and reduce their carbon footprint and greenhouse gas emissions.
OverseerFM provides a full suite of Greenhouse Gas emissions and estimates of the carbon being sequestered in trees on farm.
Understanding the amount and the sources of your farm’s greenhouse gas (GHG) emissions helps you to identify ways to manage and reduce them. For more information on this, click here.
Generating GHG reports in OverseerFM
Starting with understanding your current emissions means you have a base from which to assess the impact of any management changes you may wish to investigate.
Greenhouse gas emissions estimates are automatically generated for all Analyses (Year Ending and Predictive) in OverseerFM.
If you already have a Farm Account with a recent Year-Ending Analysis, then you can click on REPORTS in that Analysis and click on GHG. If you don’t have a recent Year-Ending Analysis then you either need to create one from scratch or copy an older one and update your management information.
Additional data regarding fuel, electricity, transport distances and fertiliser application methods can be entered in the GHG input tab to provide more farm specific details. This will be important if you are using GHG emissions information for a certification process.
Understanding the GHG reports
The GHG reports provide information on your farm’s GHG emissions profile and your tree block carbon sequestration potential.
Overseer is a farm scale model and, therefore, GHG emissions are estimated based on international Life Cycle Assessment (LCA) standards to cover “cradle-to-farm gate”, accounting for all direct and indirect and embodied GHG emissions up to the point that the product is ready to leave the farm for processing.
The GHG Reports present four types of results set out below.
The results for the GHG emissions (both farm emissions and production footprints) are based on the Overseer Science Model (For more information. click here.). It aligns with the National Agricultural Inventory Model used to report New Zealand’s sector emissions but also provides more detailed farm specific responses to management activities. The Carbon Stock results are based on the official MPI Look-up tables.
|
Report |
Results |
Units of results |
What it tells you |
|
Greenhouse Gases |
Emissions by source (CH4, N2O, CO2) |
eCO2/kg/ha/year (per hectare) |
Where emissions are being generated on-farm |
|
Total farm emissions (Total GHG emissions, CH4, N2O, CO2) |
eCO2/tonnes/year (for the total farm area) |
Your farm’s total GHG emissions |
|
|
Emissions per enterprise or area |
Emissions per enterprise or area |
Kg eCO2/kg per enterprise or kg eCO2 per hectare |
kg eCO2/kg per enterprise type, e.g. dairy, beef, sheep etc. or kg eCO2 per hectare for horticulture and arable systems |
|
Carbon Stock |
Carbon sequestration into trees over time
|
Tonnes eCO2 |
The carbon sequestration potential of your tree blocks including current carbon capture and annual capture over time. |
Using the GHG reports in farm planning decisions
Understanding the GHG emissions and carbon sequestration potential of your farm system enables you to assess different nutrient management options that will achieve your farm business goals. These could be reducing emissions or increasing sequestration potential to offset the impact of the emissions.
Seeking advice from a recognised rural professional who specialises in GHG emissions management will help to assess different possible management options and their implications for your farm business.
Assessing the Emissions by source helps you to identify where the emissions are being generated and thus areas to focus on for exploring how to manage and reduce emissions. The example below shows that the majority of emissions for this farm are enteric methane from cattle, deer and sheep. There is also a large proportion of N2O being generated from animal excreta onto paddock.
Comparing your Total Farm Emissions against your Carbon Stock potential will give you an indication of the balance of losses and capture on farm.
Using the Emissions per enterprise information provides an indicator of relative emissions efficiencies on the farm. For instance, the following example shows emissions from beef per RSU are slightly higher than those from sheep. This farm may consider a different stocking ratio of cattle and sheep as an option for the future to reduce emissions.
The Carbon Stock report shows you the potential of how your tree blocks may accumulate carbon stocks over time (cumulative). You can see the "annual carbon stocks" information by hovering on the graph on Year One, and subsequent years. This is how much additional carbon stocks your tree blocks will have sequestered in each twelve months period. From this you can assess how changes in carbon stocks might impact on your farm emissions profile over time.
Please note that there is no current policy framework in New Zealand that allows on-farm Carbon Stocks to formally offset Farm emissions. This report was developed following requests from farmers for a means of them easily understanding the sequestration potential of production forestry, shelter belts and native planted land areas.
For further information on the Carbon Stock Tool. Click here.