lanbia dairy farmers have been advised on how to reduce greenhouse gas emissions (GHGs).
What GHGs from farms cause problems?
Carbon dioxide (CO2), methane (CH4), and nitrous oxide (N02) cause problems.
The latter two are more significant in agriculture, so any reduction in them is very positive.
How much GHGs are generated on dairy farms?
A rough guide is to imagine that maintaining an average milking cow for one year gives the equivalent GHG emission of running a mid-sized petrol-driven car for one year, or 15,000 kilometres.
How can dairy farmers reduce emissions?
The simple answer is to be efficient.
You can improve efficiency on the farm, reduce greenhouse gases, and contribute to your bottom line profitability, in the following ways.
Extending the grazing season lowers GHG emissions in two ways.
Firstly, grazed grass in the early and late grazing season is a higher quality, more digestible feed than grass silage, leading to improvements in animal productivity, as well as reductions in the proportion of dietary energy lost as methane.
The shorter housing season leads to reduced slurry methane (CH4), and reduced nitrous oxide (N2O) emissions from storage, and reduced energy use in spreading.
The financial benefit comes from the improved output due to better quality feed, and from savings due to making less silage.
Increasing genetic merit, via EBI ratings, has the capacity to reduce emission intensities through four mechanisms.
Improving fertility reduces calving intervals and replacement rates, thus reducing enteric CH4 emissions per unit of dairy product.
Increasing milk yield per unit of grazed grass, and improving milk composition, increase the efficiency of production, which decreases emissions per unit of product.
Earlier calving increases the proportion of grazed grass in the diet and reduces culling and replacement rates.
Improved survival and health reduce deaths, and disease incidence, reducing replacement rates and emissions.
Nitrogen efficiency is boosted by increased use of clover in swards, thereby reducing N usage; by better nutrient management planning; by effective grazing management leading to high levels of grass production and utilization; by improvements in timing and application of fertiliser nitrogen; and by application of the most appropriate N fertiliser type for the prevailing conditions.
Improving manure management can reduce the GHG emissions associated with manure, through a transition from summer application to spring application of slurry, and through use of low-emission application methods.
Spring application reduces gas emissions following land spreading due to the more favourable weather conditions at that time of year.
And storage losses are reduced due to the shorter storage period.
The reduced ammonia loss increases the fertiliser replacement value of slurry, and therefore reduces the total fertiliser N inputs, and reduces emissions associated with fertiliser manufacture and spreading.
Low emission application technologies such as the trailing shoe reduce ammonia, and increase the fertiliser replacement value of slurry.
Improved utilisation of slurry reduces the amount of fertiliser to be purchased, and thus increases profitability.
More efficient energy use also reduces GHG emissions.
So make sure your plate cooler is working effectively.
Measure the temperature of your milk entering your bulk tank, and make sure it is not being pumped through too quickly.
Consider installing a variable speed vacuum pump.
On some farms, it can significantly reduce electricity consumption for milking, with the savings offsetting capital cost. Grants are also available.
Water heating with gas or oil reduces carbon emissions by 50%, and use of solar power can reduce it even further. Grants are available.
Consider installing a night rate electricity meter, and use timers where relevant. Ensure that all lights are energy efficient.
Monitor fuel usage on the farm, ensure there are no leaks from oil or fuel tanks. Ensure that machines are maintained regularly, to ensure they use fuel efficiently.
Any other ways to reduce GHG emissions on the dairy farm?
Aim for calving at 24 months.
Use treated urea; and increase clover in the pastures, this fixes nitrogen into the soil, thus reducing the need for fertiliser.
Add individual trees, and improve hedgerows. Consider using marginal areas for native tree planting. Trees and foliage convert carbon dioxide into oxygen.
Target a soil pH of 6.2, by using lime, this reduces GHGs by reducing the fertiliser required.
Use sexed semen to introduce more female calves.
Implement an animal health programme with the assistance of your vet. Monitor and review it each year, this improves herd health.
Reduce waste on the farm, and recycle all plastics. Do not burn plastics on the farm (burning plastics contributes greatly to GHGs).
Remove all waste chemicals, batteries, and old scrap to the appropriate recycling centres.