Where to now for farm gas research?
The taxpayer-funded hub looking for fixes to farming’s climate impact has had its funding doubled. What will it focus on? Eloise Gibson reports.
Afunding boost has bolstered the likelihood scientists will deliver a hoped-for methane vaccine – an injection to quell cows’ contribution to climate change, says a leading farming scientist.
But the chances of success remain dicey. ‘‘Vaccines aren’t easy. Just look at Covid,’’ says Harry Clark, director of the New Zealand Agricultural Greenhouse Gas Research Centre, a taxpayer-funded hub for studying ways to cut the gas from farming.
‘‘They raised $8 billion to develop a Covid-19 vaccine, and we are developing a vaccine that is technically as difficult, and we put $2m-$3m into it and think it’s a lot of money.’’
Farmers are hoping for new ways to reduce their climate impact before a price goes on a small portion of farm emissions from 2025. But big-impact breakthroughs have proved elusive.
After more than a decade’s work and over $50m in funding, an independent review found the NZAGRC was doing high-quality work – but needed to pick up the pace.
Last Budget, the Government delivered a boost: a doubling of the centre’s annual funding.
‘‘In our first iteration we got just under $50m for 10 years, in our second iteration we’ve got $50m for five years,’’ says Clark. ‘‘What we’re trying to do is build on the promising things we were already working on, and looking to see whether any new avenues are opening up.’’
Stuff nabbed an hour with Clark to find out how research efforts are going.
The vaccine
Let’s start with the moon shot. What if we could inject cows with a long-lasting treatment to keep those pesky methanogens in their guts under control? Methanogens are microbes that live in the stomachs of grass eating animals, taking excess hydrogen and turning it into methane, a powerful, though relatively short-lived, greenhouse gas.
For several years, researchers at AgResearch’s Grasslands campus in
Palmerston North have been working towards finding a vaccine.
While it hasn’t worked, the team’s international collaborators tell them they’re doing the right things, says Clark.
Having extra money means they can speed up the trial and error process. ‘‘No-one is saying it won’t work,’’ says Clark. ‘‘With more money, we can employ more people and do more things in parallel.’’
But: ‘‘There’s always a very high risk with a vaccine that you won’t succeed.’’
The rumen is almost a separate ecosystem from the cow, says Clark. ‘‘We’re targeting an organism that is not part of the animal . . . it’s an independent free-living organism . . . and it’s not in the animal’s bloodstream.
‘‘We’ve got to think, how do we target the organism by vaccinating the host?’’
Breeding climate-friendlier cows
Recent studies in sheep have shown promising gains at breeding beasts selected to burp less methane.
Now, scientists hope to do the same for the country’s 10 million cattle.
But, to make these kinds of discoveries, they need expensive equipment – full-body chambers for animals to spend time in, while scientists catch and measure all their bodily gases. That’s where some of the latest round of funding will go.
Chambers for cattle are bigger and costlier than ones for sheep – up to a quarter of a million dollars – which is one reason low-methane breeding research in cows has lagged research in sheep, although cows make more of New Zealand’s emissions.
The aim is to move beyond breeding that makes animals more efficient (which can lower methane-per-litre-of-milk, in some cases) towards identifying genetic markers of a lowermethane beast.
‘‘We’ve learned a lot in sheep and now we can apply that to cattle, but we’ve never had the measurement equipment to do it,’’ says Clark.
One option is using a small number of full-body chambers to validate faster, cheaper measurement devices, which could be used for the bulk of testing. ‘‘Eventually, we will have to phenotype something like 10,000 animals.’’
Researchers are trialling a machine called a Greenfeed, a bucket-like vacuum contraption that sucks gases from around an animal’s snout. But, says Clark, ‘‘what you really want in the long run is a saliva test or a blood test. A cheap, reliable method you can use on large numbers of animals. To get that you need to do a lot of intensive measurement.’’
The potential gains could be meaningful. ‘‘The best estimate from our sheep work is that eventually it could get as big as 20 per cent, but there are caveats.’’ For example, lower-emitting sheep tend to have smaller rumens, and it’s unclear how far breeding could shrink the rumen without harming a sheep’s health or productivity.
Powders and potions
Another focus has been finding compounds to add to an animal’s feed, to shrink how much methane it burps – perhaps by a third or more.
As with a lot of NZAGRC’s work, this research was done in tandem with the Pastoral Greenhouse Gas Research Consortium, which is funded by various farming organisations.
Clark says animal trials found a shortlist of compounds that were proven to work. The PGGRC is negotiating with potential investors to get them to market.
Meanwhile, Dutch company DSM is hoping to adapt a competing powder, called 3-NOP, so it can be fed to New Zealand’s grazing cows. Right now, it’s more suitable for cattle in barns and feedlots – using it here would require finding a slowrelease formula.
Researchers had hoped 3-NOP-treated animals would turn the energy they would have wasted burping methane into extra meat and milk, but that hasn’t shown up in published trials, says Clark. That means farmers may need an emissions price or some other regulatory incentive before they’d use such additives.
The Government may also need to find a clear path for getting environmentally beneficial feed additives cleared as safe to use in the food chain, he says.
Planet-friendlier fertilisers
Remember DCD? It was the nitrogen-fixing fertiliser that was going to lower New Zealand’s emissions of nitrous oxide, and cut nitrogen run-off to rivers, but had to be suddenly pulled from the market after small traces showed up in milk.
After methane, nitrous oxide from livestock urine hitting paddocks is farming’s biggest source of greenhouse gas.
Clark says the regulatory regime has now been altered so ‘‘there’s a possibility DCD could come back on to the market’’.
‘‘But there’ll be a strong degree of wariness that, although you can show it’s safe, there’s a perception around it that makes any commercial company hesitant about re-launching it. That’s still to be played out.’’
NZAGRC has a programme looking at alternatives to DCD, and has found compounds that could work in a similar vein, says Clark. Some are still at the lab-trial stage, but one is in fieldtesting, where it’s proving promising, he says.
More than that, Clark can’t say, for reasons of intellectual property. He will say they’re looking at a more targeted application than DCD, which was spread on the whole paddock.
They’re working with the makers of a New Zealandinvented, tractor-drawn device called Spikey, which rolls over paddocks to detect and treat urine patches.
Diet
Researchers around the world have tried feeding cattle all sorts of things to lower methane, but too often it comes with some unpalatable trade-off.
One very promising plant for New Zealand conditions is plantain, which seems to reduce nitrogen flowing off farm paddocks into waterways, and reduce the nitrous gas, by acting on the cow, soil and pasture in multiple ways.
The challenge with plantain is getting cows to eat enough of it, says Clark. ‘‘You need a minimum amount in the diet, so the challenge becomes how do you manage a plant like that to get sufficient quantities . . . on a continuous basis.’’
Add it together?
In an ideal world, farmers will one day put all these things together – but that, too, needs more research, says Clark. ‘‘Once you’ve got a low-emitting animal, can you then put an inhibitor with that and feed [a low-emissions] sort of feed. Are they additive?
‘‘We don’t know, but I think eventually that’s what we’ll do, because it’s a stiff challenge to get the numbers down to where we want to get them.’’