From our Chair: Dairy intensification – can we do more with less?

As the new Chair of Environment Canterbury, I would like to use this column to engage with you and other people living or working in Canterbury.

Environment Canterbury Chair Jenny Hughey

Environment Canterbury Chair Jenny Hughey

Reducing cow numbers

Earlier this year a media article reported me as saying cow numbers on the Canterbury Plains had to be reduced 25% and that research at the Lincoln University demonstration farm and elsewhere has proven this to be possible over time. There was, however, no other explanation, and this column is a good opportunity to put some context around the report.

There’s little argument that dairying is a hot topic in New Zealand, with environmental groups on one side attacking the industry for poor practices and environmental damage, while DairyNZ and other farmer groups say dairying has made huge strides in recent years not only to protect the environment, but also in beginning to turn around the damage caused by many decades of increasing intensification of farming.

Some people point to these conflicts as evidence of a deep rural-urban divide in New Zealand, which I addressed as nonsense in my previous column.

The issue isn’t just about nutrient pollution (N and P), sediment and bacterial contamination of our waterways, it also includes the very sensitive subject of greenhouse gas emissions and how the recommendations of the Interim Climate Change Committee will be implemented and how they will affect farmers.

Lowering greenhouse gases and nutrient pollution

While a call to reduce cow numbers might seem a simplistic response to the farming community, it would have an immediate effect on greenhouse gas emissions from the agricultural sector.

There is also a lot of evidence that dairy farmers can maintain production and profitability while cutting nitrate emissions.

Trials at the Lincoln University demonstration farm showed that a low-input pasture-first model could result in the same level of production from fewer cows, and a significant reduction in the farm’s nitrate leaching.

Remember the Lincoln University demonstration farm has open days each year where farmers are invited to come along and hear about the latest research and how they can apply it on their property.

Research at other model farms in Canterbury has shown production can be maintained while achieving a reduction in nitrate leaching of nearly half. 

Benefits of making changes now

The work to achieve such results has been incremental over many years and the message from farmers leading such programmes is to get started and to make the improvements before you need to. 

In the long-run that will be a lot easier than having to try to make significant short-term reductions because of regulations.

This on-farm research to reduce nitrate leaching began with improved irrigation efficiency and management, followed by better effluent management and water use efficiency.

A reduction in N fertiliser rates was trialled (both amount and frequency) without affecting pasture growth rates.

High N feed supplements were replaced with low N options as well as a catch-crop of oats to mop up residual N. Plantain was also introduced, initially to just a couple of paddocks, which helps reduce the N concentration in urine.

Send your feedback

It is my view that the science is telling us that to protect our environment for the future we need to reduce both greenhouse gases and nutrient pollution. I am interested in hearing your views – please email me at