Warning green fears could make farming more industrialised

Ag Research sheep are fitted with a measuring device to detect the amounts of nitrous oxide emitted from their urine. Photo / Bruce Mercer

Images of carefree cows roaming free, chewing grass or silage year round (well, almost), used to be the green selling point of New Zealand's dairy industry.

Not for us those "factory farms" of the Northern Hemisphere where the poor cows are consigned to sheds and fed grain for long periods.

But Federated Farmers' president Don Nicholson says greenies should be careful what they wish for. Their agitation about dirty dairying has led New Zealand farmers to import foreign concepts such as feed sheds to keep cows, and their effluent, off paddocks in winter.

Increased use of feed pads and stand-off pads is touted as improving productivity while reducing the problem of nitrate from urinating cows leaching into waterways when soils are wettest. Nitrous oxide from urine patches also contributes to our greenhouse gas emissions when plants aren't growing and absorb less nitrogen.

"The greenies love the free range grazing regime but their influence has made farmers more industrialised," says Nicholson.

"In Southland especially, farmers are actually building big feed sheds for 600 to 700 cows and taking them to milking without crossing a paddock. The greenies have made industrialised farming start to happen here."

The Green Party this week further raised farmers' hackles when it unveiled its recipe for reducing our greenhouse gas emissions excess ahead of next week's Government announcement of a target figure. The Green Party reckons we could shave 36 million tonnes off our emissions and thereby hugely reduce our obligation to buy carbon credits at enormous cost. It found potential savings in agriculture of 2.7 million tonnes by 2020 if dairy farmers reduce the number of stock they run from an average 2.8 cows per hectare to 2.3. On sheep, beef and deer farms, management tools such as diet changes and better soil drainage could reduce nitrous oxide and save another half a million tonnes, said the Greens.

The party tried to sweeten the deal for dairying by suggesting that the current high stocking levels, with requisite high use of fertilisers and supplementary feed, were unprofitable once milk payouts were below a certain level - $5.50 a kilo of milk solids - as they are now.

The hard sell: farming less intensively by lowering stocking rates and reducing fertiliser inputs could actually increase profitability.

DairyNZ, which represents dairy farmers, was quick to brand the Green Party study "incorrect and misleading".

"DairyNZ has proven that profit is very closely linked to the efficient harvest of pasture by cows, which in turn, is strongly influenced by stocking rate," said CEO Tim Mackie.

In the climate change mitigation debate, agriculture - responsible for 47 per cent of our greenhouse gas emissions - has positioned itself as the sacred cow. Methane belched from the stomachs of cows and sheep and nitrous oxide from their urine are the culprits.

Scientists reckon 1kg of nitrous oxide has the same greenhouse effect as 310kg of carbon dioxide while 1kg of methane emits the equivalent of 21kg of carbon dioxide. A dairy cow emits the methane equivalent of 4600kg of carbon dioxide per hectare per year, according to Landcare Research.

But measures to tackle these emissions (remember the sheep wearing gas masks and the fart tax?) have been chewed up and spat out like wheat through a combine harvester by farmers - often with townies on board, such is the efficiency of the farm PR machine.

The message propagated is that there's little that can be done to reduce farm emissions, that agriculture is the backbone of this fragile nation's economy and we mess with it at our peril. Farmers know that's not quite the case but it suits them to blame greenies (they have a long list of other complaints) and tug at heartstrings while science develops more palatable measures to combat agricultural emissions - ones that don't hurt farmers' pockets.

New Zealand is emerging as an international leader in applying research to reduce pastoral emissions. While it's early days, the potential to reduce agricultural emissions by considerably more than the Green Party's 2.7 million tonnes appears strong.

The industry, the Ministry of Agriculture and research organisations including AgResearch and Landcare Research are currently pouring millions of taxpayer and industry-funded dollars into finding solutions, some of it under the umbrella of the Pastoral Greenhouse Gas Research Consortium.

Options range from soil and feed management techniques already out there to high-end science including microbial analysis in the rumen (the fore-stomach of ruminants where methane is produced) and genetically modified crops.

Mark Aspin, manager of the Pastoral Greenhouse Gas Research Consortium, says it's important that any changes in emissions can be measured and monitored on-farm. New Zealand's varied soils and climate mean what works in some areas may not work in others. "We have to be realistic," he says. "This is 80 to 90 million years of evolution we are trying to turn around in a short period."

"There are two reasons for doing it - one is to reduce greenhouse gas emissions and the second is to enhance understanding of how we can make ruminants more efficient. We're looking for solutions that deliver on both."

Aspin says lower stocking would reduce emissions "but it's a bit of a blunt instrument."

"The issue is about still being able to make a quid," he says.

"Our animals over time are getting more effective and more efficient - we are selecting superior genes in our livestock and our plants that we feed them. But ultimately people have still got to make an income and run an efficient business."

Agresearch principal scientist Stewart Ledgard says the key is to develop reduction measures which dairy and sheep farmers will use because they bring efficiency gains - more milk solids per cow or more lamb weight per ewe per year.

Lower intensity dairying would no doubt lower emissions, says Ledgard. Higher stocking rates have brought increased use of nitrogen fertiliser (urea) and increased use of feed which has a carbon cost.

But with improved farm management techniques, higher intensity systems could produce the same emissions per kilo of milk as low intensity, he says.

"It depends on how efficient they are at pasture production and converting that into milk."

Ledgard says potential emission reductions of 10 to 20 per cent are achievable if some of the practices being worked on are implemented.

Ledgard has spent several years researching life cycle assessments, focusing on carbon footprinting of dairying and identifying current emissions per kg of milk.

"The limited amount of work that's been done looking at greenhouse gas emissions per kilogram of milk indicates we are quite efficient compared to European countries."

Nicholson agrees that farmers will come on board when they can see efficiency and productivity benefits.

"It won't be done by coercion. Farmers just by good business practice pick up the best technology to make their farms more efficient."

"We want to get more output for less or the same inputs - that's what we're after and that's what New Zealand Inc should be after as well."