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Greenhouse Gases

Are you aware that most farmers and growers will need to know their annual on-farm greenhouse gas (GHG) emissions by December 2022? And by January 2025, everyone will have to include GHG management in their Farm Environment Plans and be participating in an annual GHG reporting system.  This is all leading towards a price being applied to agricultural GHG emissions from the start of 2025.

The government has set a target to reduce biological methane by 10% (from 2017 levels) by 2030.

Owl Farm has been demonstrating best practice management to reduce GHG since its inception.  At the March 2019 Farmer Focus Day, as a Partner Farm we hosted the GHG Partner Farm Launch in conjunction with DairyNZ for the Dairy Action for Climate Change (DACC) project.

Owl Farm has continued to be involved in the DairyNZ Step Change project which is designed to help dairy farmers achieve financial gains, while making progress towards environmental goals and adapting to pending regulations. Overseer and DairyBase are used as key tools to measure change over time.


The journey to date:

From 2014-15 to 2020-21 Owl Farm has reduced biological GHG by 7% (methane and nitrous oxide). This includes a reduction in methane of 6.7%.  This difference over the six years includes a 1.5% reduction in kg MS/ha (to 1,237 kg MS/ha) and a 2.5% increase in production per cow (to 440 kg MS/cow/year), while Operating Profit has increased 45% to $3,482/ha.
As a System 2 farm, our production is strongly influenced by rainfall and increases in milk production, feed eaten and therefore methane production.  Data trends show that we have been able to make reductions in emissions while maintaining a productive and profitable farm business.
Changes over the six years include:
  • Reduced stocking rate (less methane) with reduced urine patches (less nitrous oxide)
  • Reduction in imported supplements (less methane)
  • Breed high BW cows currently top 6% nationally (less methane and nitrous oxide)
  • Reduce replacement rate using sexed semen and focusing on meeting youngstock growth targets (less methane and nitrous oxide)
  • New pastures planted with Ecotain Plantain (4 kg/ha) (less methane and nitrous oxide)
  • Retire and plant unproductive land (less methane and increased carbon dioxide sequestration)
  • Reduce nitrogen application rates to below 30 kg N/ha per application (less nitrous oxide)
  • Use SustaiN and Smartfert (less nitrous oxide)
  • Upgrade effluent storage facilities to eliminate spreading during the winter months (less nitrous oxide)
  • Increase effluent area (less nitrous oxide)
  • Reduce nitrogen application during May – July (less nitrous oxide)
  • Use soil moisture probe and soil temperature data to ensure nitrogen is applied when soil temperatures are above 10°C and soil moisture levels are above stress point (less nitrous oxide).
  • Conduct Soil Total N tests to determine most efficient use of nitrogen (less nitrous oxide)
  • Reduce total nitrogen used in conjunction with My Pasture Planner (less nitrous oxide)
  • Constructed wetland with 63% removal of nitrates from a 7.6 ha catchment area (less nitrous oxide, more carbon sequestration)
  • Zero cultivation using direct drilling of Cleancrop varieties for all crops (less carbon dioxide).


The journey continues:

In the winter of 2020 Waikato University installed a CO2 tower on the farm to investigate the effect of turnip cropping on soil carbon and greenhouse gas emissions. Owl Farm contributes data to this valuable research; more information can be obtained by contacting Aaron Wall at the University of Waikato.

Owl Farm has been focused on generating profit to pay down debt over the last three seasons, to position the business to continue investing in technology/systems infrastructure as they become proven in NZ dairy systems. We continue to invest in top genetics to convert high quality feed into milk.  We are watching closely the research currently underway on:

  • Breeding low-emitting dairy cattle
  • Alternative feeds, including forage rape and plantain
  • Methane inhibitors