Carbon awareness for dairy farmers

January 13, 2022

CAFRE in partnership with the UFU and NI Dairy Council ran a series of webinars in the autumn on the theme “Future Proofing your Dairy Business”. The first webinar was entitled “Carbon Awareness” and looked at the greenhouse gases (GHG) emitted from NI dairy farms and how they can be reduced. Dr. Mike Johnston, CEO of the NI Dairy Council, highlighted how the carbon intensity of milk production in NI had reduced by a third over the past three decades mainly due to the increase in milk yield but he stressed that there is still a long journey to go and not without pain. “Customers for dairy products are taking an active interest in climate change and the industry’s environmental credentials must be at least as good as or better than our competitors” Dr. Johnston stated. He concluded by stating that these environmental targets will be challenging but with the right legislative framework, collaboration between industry, research and government, farmers will be given the knowledge and incentive to reduce their emissions and continue to produce high quality milk in a more sustainable way.

Aleathea Brown, Senior CAFRE Technologist, noted that agriculture is responsible for approximately 26% of GHG emissions in NI and will have to make a contribution to the UK’s target to be net zero by 2050. Currently there is no climate legislation in NI but there are two bills being scrutinized by NI Assembly’s Agriculture Committee. Aleathea then outlined the main GHG’s associated with dairy farming. Methane (CH4) is the largest accounting for nearly half of the emissions followed by carbon dioxide (CO2) and then nitrous oxide (N20). Aleathea noted that despite methane being a short lived gas it has a global warming potential (GWP) 28 times that of CO2 whereas N20 has a GWP of 268 and has a life span of about 150 years. The main sources of these GHG’s are as follows:

• CH4 – rumen fermentation and manure storage
• CO2 – feed and fertiliser imported onto the farm
• N2O – breakdown of the nitrogen compounds in fertiliser and manure by soil microbes

Michaela Tener, CAFRE Technologist, explained that a dairy farm’s carbon footprint was the amount of GHG emissions per kg of milk produced. To calculate a footprint, the main information required is milk / livestock sales, concentrates fed, fertilisers and manures applied. Breaking down a typical dairy farm carbon footprint she highlighted the main sources of emissions are from rumen fermentation 40%, concentrates 25%, manure management 20%, fertiliser 13% and fuel at 2%.

The New Year is an opportune time to assess your dairy farm’s carbon footprint for 2021 and for any dairy farmer currently in a CAFRE Business Development Group, contact your local CAFRE adviser who will facilitate carbon benchmarking. The results will present a picture of the current carbon footprint position. If higher than recommended then Michaela has listed the following advice common to all types of production systems in an attempt to reduce the carbon footprint:

• Develop a herd health plan
• Use genetic selection and sexed semen for replacements
• Keep replacements to a minimum and aim to calve at 24 months
• Target concentrate feeding and don’t overfeed dietary protein
• Use LESSE to increase nitrogen availability from manures
• Apply majority of manures in spring for greater utilisation
• Use protected fertiliser and include clover in grazing swards
• Avoid ground compaction and maintain soil at optimum pH and nutrient status.

Dairy farmers have faced many challenges to date and this one can be overcome with knowledge through carbon benchmarking and a change in focus if necessary. In relation to future strategies to reduce farm carbon emissions, two with the most potential are the use of feed and slurry additives and the use of genomics to breed animals with high feed efficiency, which will lower methane emissions.

If you missed the autumn webinars you can now catch up on carbon awareness by visiting www.cafre.ac.uk/future-proofing-your-dairy-business-webinar-recordings/