Summarised by Centrist
A five-year Northland dairy trial found that reducing farm emissions without new technology came with substantial production and profit costs.
The Northland Dairy Development Trust compared three systems at the Northland Agricultural Research Farm near Dargaville: a conventional baseline farm, a farm using alternative pasture species, and a low-emissions farm with fewer cows and no nitrogen fertiliser.
The low-emissions system produced 26% less methane and 46% less nitrous oxide on average over the five years.
However, milk production was between 20% and 39% lower than on the baseline farm.
The low-emissions farm also recorded an average operating profit of $698 per hectare less than the baseline system, although it was not the least profitable option in two of the five years.
Trust coordinator Kim Robinson said the cost of cutting emissions without technology was “significant and unsustainable”.
She said many farmers were likely to wait for cheaper emissions-reduction technology or stronger financial incentives before making major changes to their farm systems.
The trial also tested alternatives to perennial ryegrass, including tall fescue and cocksfoot-based pastures.
The alternative pasture system produced similar average operating profits to the baseline farm and delivered the highest milk production in two of the five seasons.
The findings suggest lower-emissions farming is technically possible, but under the system tested it required farmers to accept lower milk output and reduced profitability.
