Can agriculture meet its methane targets?

New Zealand agrculture is required to achieve a ten percent reduction in its methane emissions by 2030.  This is set down in legislation. The subsequent 2050 target, also laid out in legislation, has been set in the range of 24-47 percent, with the specific requirement within this range still to be determined. The question addressed here is whether these targets are realistic and what do they mean for the future of pastoral agriculture?

The reason this is such an important question is that pastoral exports from dairy, sheep, beef and venison comprise some 50 percent of New Zealand’s merchandise exports. Add in horticulture, fish and forestry, and the overall primary industries contribution to exports rises to over 80 percent. These export percentages have been increasing each year for the last ten years.

Looked at another way, non-primary-industry exports have been steadily declining as share of total exports, something very poorly understood within broader society.

Without exports, New Zealand cannot fund imports.  And without imports, the whole economy falls over.

Approximately half of the pastoral-sourced methane is generated on dairy farms and just under half on sheep and beef farms. However, the impact of a methane levy will be felt most fiercely by sheep and beef. This is because there is less economic resilience in the sheep and beef industries to withstand the levies.

To understand the reduction pathways, the starting point is to recognise that methane production is a direct function of the total amount of feed eaten by pastoral animals, which in turn is driven by the amount of feed grown. Accordingly, the amount of feed grown and eaten has to decline by about ten percent by 2030.

Unless new technologies become available that reduce the amount of methane from each kilogram of feed that is eaten, there is no other alternative way to meet the reduction.

There is one possible caveat to the above statement. About five percent of the methane on dairy farms is associated with effluent ponds, and there is a new technology, already close to commercialisation, that can totally smash these effluent pond emissions. Trademarked as the ‘Ecopond’ technology, it is based on adding controlled levels of ferric sulphate to effluent ponds, with this making the effluent pond an unsuitable environment for methane-producing bacteria, and no environmental downsides.

The Ecopond science has been developed and proven at Lincoln University. Ravensdown is now proceeding with commercialisation. Already installed on two pilot farms, hopefully the system will be commercially available within the next year.

If the Ecopond systems are fully implemented, then methane from dairy farms would reduce by about 5 percent. Across the total pastoral system, that would mean savings of about 2.5 percent.

So, even assuming full implementation, that still leaves 7.5 percent further reduction required by 2030. This can only be done by reducing the amount of feed consumed by dairy, sheep and beef. The pathway to that lies in converting some sheep and beef land to forestry, together with a likely decrease in the number of dairy cows in response to regulatory constraints.

However, this does not necessarily mean that the volume of pastoral products has to decline.   This is because increasing the biological efficiency of production, with less feed consumed per unit of product, also leads directly to less methane emissions per unit of product. In essence, it is all about production systems that reduce the amount of feed required for maintenance, thereby leaving more feed available to drive production.

I mentioned in a recent article that methane emissions per kg of New Zealand lamb meat are estimated to have decreased by 31 percent since 1990/91. This has been a direct result of much higher carcass weights and much higher lambing percentages, with ewe size only increasing marginally.   These biological efficiency gains then flow through directly to the same efficiency gains in terms of lower methane emissions per unit of product.

About seven years ago I was adviser for a PhD study by Peter Klaassen that explored the potential for further increases in biological efficiency within sheep farming. Peter demonstrated how there was no one factor. Rather, it was going to be a case of working on multiple factors including further increases in lambing percentage, plus lower death rates, perhaps more lambing as hoggets, and perhaps even higher carcass weights. But with each progressive step, further improvement becomes increasingly challenging.

Some weeks back, I spent a morning with Professor Derrick Moot at Lincoln discussing what further improvements we could see forthcoming from known technologies in regard to methane emissions from sheep. We both think that a further ten percent is realistic, but getting there by 2030 could be a very big ask.

In contrast to sheep, productivity improvements in cattle, and hence lower intensity of methane production, have been modest at about eight percent over the last 30 years. This is largely because cattle are not designed to produce twins, and they cannot be convinced otherwise. Also, cattle have always been slaughtered at close to their mature liveweight. But further reductions in methane intensity can still occur as better use is made of the surplus calves from the dairy industry. Use of sex-selected semen to produce dairy females and crossbred-beef males will be fundamental to this occurring. Although already widely used, some fine tuning of the technology is still needed.

I then went digging to see what I could find about reduced methane intensity in New Zealand dairying, using the key performance indicator of feed eaten per kg of Milksolids (fat plus protein). I found a DairyNZ paper prepared for MPI in 2021 estimating that in 1990/91 the average cow weighed 470 kg, produced 243 kg Milksolids, and ate 3.87 tonnes of dry matter. By 2019/20, the average cow still weighed 470 kg (by coincidence) but produced 376 kg Milksolids and ate 4.76 tonnes of dry matter.  I then did some calculations to come up with an estimate that the biological efficiency increase had been 21 percent, with this flowing through to the same improvement in terms of reduced intensity of methane production.  Although not quite as spectacular as the improvements with sheep, it has still been a remarkable improvement.

I then looked at what would happen if Milksolids production per kg of liveweight increased from the 2019/20 figure of 0.8 kg of Milksolids per kg liveweight to 1.0 kg Milksolids for each kg of liveweight. The biological efficiency would increase by a further 9 percent and methane emission intensity would drop by a similar amount.

Most of the farmers that I work with are already operating with Milksolids production per cow at between 0.9 and 1.2 kg of Milksolids per kg of liveweight. So, getting the average for the industry up to a 1:1 ratio would seem a worthy goal.

Bringing this all together, achieving ten percent reduction in methane emissions by 2030 looks feasible but challenging. It can only happen if some of the marginal sheep and beef country is converted to forestry – something in excess of 500,000 hectares. My key concern is that this occurs on the genuinely steep marginal country, and with a focus on non-harvested forests, rather than short-cycle production forests of which we already have close to two million hectares.

As part of the equation, New Zealand has to decide whether it is serious about the Paris commitment that all countries made as to the importance of maintaining food production. Also, if New Zealand is to avoid shooting itself in the foot in regard to export industries, then in taking a step forward there has to be a focus on what is already known in regard to driving further efficiencies in farming systems.

When I started writing this article, I planned to extend the analysis through to the post-2030 years leading to the much tougher 2050 target range of 24-47 percent. However, that will have to wait for another time. What I will say here is that it is going to be exceptionally difficult to retain vibrant export industries and still get within that target range, unless some commercial technologies applicable to pastoral conditions become available. These technologies would need to inhibit methane-producing bacteria in the rumen but without reducing animal productivity.

The extent of the challenge should be a concern for all New Zealanders. The export alternatives to pastoral agriculture on hilly lands exposed to a South Pacific maritime climate are far from obvious.

About Keith Woodford

Keith Woodford is an independent consultant, based in New Zealand, who works internationally on agri-food systems and rural development projects. He holds honorary positions as Professor of Agri-Food Systems at Lincoln University, New Zealand, and as Senior Research Fellow at the Contemporary China Research Centre at Victoria University, Wellington.
This entry was posted in Agribusiness, Dairy, sheep and beef farms, Uncategorized. Bookmark the permalink.

21 Responses to Can agriculture meet its methane targets?

  1. John McEwan says:

    Keith, as usual, a thought provoking article. I am sure MPI and others have been through these calculations a few times. I just want to add a few points. If I understand you correctly, the efficiency gains mentioned here assume no change in CH4 per kgDMI (methane per unit feed eaten), just more product (sheep meat, beef, dairy) per kg DMI. So maintaining production to 2030 needs a 10% decrease in feed consumed (aka land conversion to forestry, or less nitrogen used ….). If so, there are several other knock-on effects. At first glance, in real terms, income from the pastoral industry would appear to stagnate. In fact, it would likely still increase but more slowly because of a) higher value end products developed and b) increase in demand for protein products from world population growth as previous increases in exports have kept the supply-demand roughly in balance. I view this as the default worst-case scenario. Where do these efficiency gains (product/kg DMI) come from? Much, but not all, for sheep and dairy, is from genetic improvement. This raises the question of whether methane produced per kg DMI can also be reduced by genetics and the answer is yes. However, will it alone reduce methane emissions by 47% by 2050 while also increasing efficiency (product/kg DMI) by the present rate? I think it would be a big ask and I suspect gene-editing, genotyping embryos and various reproduction technologies would need to be involved. However, it can, and I hope will make a contribution. Hence the need for other technologies including modified forages (genetic engineering again), vaccines and inhibitors.

    • Keith Woodford says:

      One of the challenges is that it is the genetics of the bacteria rather than the animal itself that determines the methane production. So, to produce low-emission animals it is necessary to breed animals with rumen conditions that the methane-producing bacteria don’t like, but which non-methane-producing bacteria do like. This is possible but not easy because the relationship between the methane-producing bacteria and their ruminant hosts is strongly symbiotic.
      Efforts are currently under way to produce such ruminants and there is some enthusiasm among animal breeders for results to date. However, I remain cautious because there is still lots to be learned under field conditions away from the lab.

    • Dr. Thomas Grupp says:

      Isn’t it now the time for ‚dual purpose‘ cattle breeds, to produce milk & beef on a high level?
      Like in Holland, the ‚Fleckviehs‘ gain more and more traction in purebreeding & crossbreeding programs! Heterosis effects plus outstanding finishing qualities of Fleckvieh x Jersey/Kiwi or Holsteins calves could be a very cheap ‚game changer’!

      • Keith Woodford says:

        Flekvieh are definitely a very interesting species. But they have never really taken off in NZ despite availability of semen.

  2. Mark Belton says:

    Thank you Keith, an extremely helpful explanation of how to achieve a 10% reduction in livestock farming CH4 emissions by 2030.
    There are many actions required, the biggest being retirement of the most marginal hill country, and establishing 500,000 ha as permanent carbon forest thereon. This should be done with diverse tree species for soil erosion control as well as for carbon sequestration because we need to future proof our steep high erosion risk hill country, build more resilience into our farming systems, as we face radical increases in the frequency of high intensity rainstorms. .. Mark Belton

  3. Simon Redmond says:

    Good article, Sheep and Beef are in the firing line because they are close to their biological limits and have less financial resilience as you pointed out. In a similar way to Beef Study, for my dairy clients I can get them to the required targets through a variety of measures without resorting to effluent pond capture or feed additives. It gets harder the higher the feed conversion efficiency is for the farmer which opens up another interesting question….

    • Keith Woodford says:

      If individual farmers are to achieve the target then it has to be by a combination of greater efficiency plus retirement of some land. If all land stays in production, then the methane production will stay the same but production of pastoral products will increase.
      However, at the industry level, if some marginal land is converted to forestry then this will lead to lower methane production while maintaining overall production of pastoral products.

      • Simon says:

        Thank you for taking the time to reply. I agree totally with your comment. The problem NZ inc faces is we have committed to reduce greenhouse gas emissions. The biggest two levers are transport and methane.

  4. david walton says:

    Keith a great and logical read;;
    What puzzles me is that we can deal to viruses with new vaccine technologies and there have been enormous strides in RNA and other gene based science
    Is it that humans and research here is not communicated to animal science ? With the climate destructive methane the human and humanity would suffer ;
    How much collusion is there between scietists of each persuasion?

    • Keith Woodford says:

      In many cases it is the animals scientists that lead, in part because it is easier to test ideas on animals than humans. And then the human scientists follow.
      A big problem with a methane inhibiting vaccine is that the antibodies have to somehow get back out of the bloodstream and into the rumen. As a general rule, nature has figured out that it is best not to attack foreign organisms while they are in the digestive system. Instead, it is better if the job in the digestive system is left to enzymes, and then the immune system takes over when nasties get through into the circulatory system.

  5. Rod mckenzie says:

    Keith. Very informative blog. You didn’t mention the use of methane inhibiting seaweed for dairy cows. I am guessing you have no confidence in that technology

    • Keith Woodford says:

      It is not so much a case of having no confidence, but there are multiple steps to be taken before it is functional in a pastoral system. I suspect it will be expensive to get from the ocean to the cow.
      There is already a probiotic that works, but it has to be mixed with the feed. It will work if added to supplements but at this stage does not work in association with grazed pasture.

  6. Jason Barrier says:

    And the rural communities presently supported by this 500,000ha of so-called ‘marginal land’ Keith? What is to become of them? Just more ‘collateral damage’ in our vainglorious attempt to offset emissions from the likes of China, India, and US who won’t restrict their own agriculture. Meanwhile ‘carbon leakage’ will most definitely occur as Brazil will happily supply every tonne of meat we don’t. – thus net emissions will rise and more rainforests will disappear. We might well meet this arbitrary 10% reduction target but the world be warmer as a result. Hardly a good outcome for our children.

    • Keith Woodford says:

      And what do you suggest as the way forward for the steep Class 7 country?

      • Jason Barrier says:

        1. Either continue to farm them in an environmentally sustainable non-intensive way, (as most of them are currently managed) or 2. Plant them if they are in highly erosion-prone areas and the farmer wishes to speculate on the carbon price but importantly keep those plantings to a cap of 20% per farm so that it does not stuff up whole communities and exports in the long run, (as this cap would reduce the incentive for carbon companies to buy up whole farms). We must be the only country in the world looking to decrease our food production at a time when food security is such an issue – nuts! We need to start talking about how do we as a country produce MORE food in an environmentally sustainable way.

  7. Jeff Lagan says:

    HI Keith, I am a farm consultant based in Hawera

    What I think needs addressing in the dairy industry environment is like looking at reducing stocking rates by 10% which might see production drop by say 5 %

    Work done by Hutton and Parker at Ruakura 50 years ago showed an extra C.S wa200 kgs/DM and gave a response of 17.5 kgs/ms/cow

    Reducing cow stocking rate should see mating% improve as every empty cow cost $1000 (that is an incalf cow is $12800 v an empty at $800

    I remember consulting in Canterbury some 30 years ago where a farmer at Arundel (probably Canterbury’s first 1000 cow farm had 30% MT’s)

    When we sorted out his mating problem which was the current Canterbury problem (AB technician and silage contractor both arrived on the same day) it almost bankrupted him when instead of 300 culls coming in over mating culling dropped to only 100 cows then more cows in calf early meant more peak milk, less heifers to rear like about 150 less

    We now have farmer accepting MT rates above 15%!! More in calf cows should lead to less heifers needed

    It would see less PKE used and then an environment tax on any use of PKE after 50 tonnes of $10 tonne(It really is equivalent as a feed to sawdust anyway!! )

    Molasses in Taranaki today I was told is $ 532 delivered so all feed is at momentous prices

    I have a son (ex Lincoln B Ag valuation )who is based in Wagga Wagga when I was there at Easter all farms had barley under cover in 40x25x5 metres stacks we should be importing feed barley is about $280 tonne in Southern NSW

    Then get the stick out on urea, Ants Roberts who worked at Normanby at the same time as I did 40 years ago showed in Taranaki there was no autumn response to nitrogen below 600 foot (180 metres)I guess that applies in Canterbury, North Otago and Southland as well as 75% of the dairying area of Taranaki. All of the Manawatu say half of the Waikato Limit urea N from the 183 kgs N/ha that some clown has come up with to 80 kgs/N/ha

    The PKE is really for Fonterra to drive which is why they discovered a FEI >9 could not make butter



  8. Hi Keith et al
    Thank you for your thoughts and the discussion your writing facilitates – insightful and the ensuing discussion helpful.
    I am also influenced by the work of Dr. William Rees population ecologist, ecological economist: ecological footprint analysis, and dysfunctional overshoot.
    “The human enterprise, the economy, and all eight billion of us are using biological resources … faster than they can regenerate and we’re producing wastes far in excess of the assimilative capacities of the ecosphere.” and
    “One result of our simplistic reductionist way of looking at things is that we tend to fixate on single problems at a time. Climate change is in fact, the distraction from the greater meta-problem.”
    Perhaps NZ’s quest for ever greater efficiency to mitigate the ecological impact of production systems that are inherently unsustainable is not the best course?
    “Without exports, New Zealand cannot fund imports. And without imports, the whole economy falls over.”
    Keith, isn’t this so simplistic as to be unhelpful? If Rees is right, then the economy of NZ in a few short decades will bear little resemblance to the economy of today.
    Ecological overshoot will be managed either because we collectively deal with it or we suffer the consequence of the chaos and collapse. Either way shipping inputs around the planet to produce products that are not essential to life is unlikely to underpin the future “economy” of NZ.
    The Planetary Boundaries framework is a useful construct that helps develop policy. “A safe operating space for New Zealand/Aotearoa: Translating the planetary boundaries framework” is clear that we have already pushed the local Earth System far; Climate, Land-system change, Freshwater, Biogeochemical flows, Biosphere integrity.
    Would it be useful to consider the possibility of significantly reducing the production of “food” – animal protein, and pivot towards the production of foods for plant-based diets , using production systems that operate within the constraints of the local resources available?
    As Rees so succinctly says “the chief virtue of self-delusion is that it enables one to ignore discomforting aspects of reality.”

    • Keith Woodford says:

      I agree about planetary boundaries.
      However, trying to grow plant crops on most NZ pastoral soils would be an ecological disaster.
      Most of the good cropping soils are already used for crops (and houses!).
      The percentage of NZ land that is class 1 is only 0.7% and the Class 2 percentage is 4.5%.
      Class 1 soils are typically used for vegetable production.
      Class 2 are typically used for ‘mixed cropping’ which incudes an animal phase for maintenance of the system

      Click to access nzgrassland_publication_49.pdf

      Soils that have high cropping capacity are well understood and this is reflected in the price for which they sell.
      New Zealand’s geographical isolation plus maritime climate are additional constraining factors. For example, we often have to dry broadacre crops such as wheat and this is energy intensive.

  9. Horace Smith says:

    An interesting blog I appreciate the conversation it encourages
    What is the vision of success? I myself see it in stark and blunt terms:
    1 two dimensional intensive lowland (most likely polluting) and afforested hill country, or
    2 a multi-dimensional landscape that is a mosaic of diverse and different land use having good fit.
    The latter will support viable rural community having a range of employment opportunity, it would be more aesthetically pleasing, there would be greater balance and harmony supportive of biodiversity, and the environment ecosystem health would not be compromised remaining functional with good vitality.
    With a vision of success in mind policies about land use and associated effects must be managed in an integrated non-siloed manner. Consequently how we manage GHG emissions must also be fully integrated mindful of unintended consequence.
    HWEN is a debacle supposedly a partnership but reality is one partner has ruled the roost.
    How is it the sector with the highest environmental footprint, climate and freshwater, with the least biodiversity is relatively immune from real behaviour change from the proposed HWEN emission pricing. Conversely, the sector with a low environmental footprint that includes a warming neutral emission profile will be significantly squeezed to capitulate ultimately to sell up for carbon afforestation. The B+LNZ report clearly identifies a good number of farmers will no longer be sustainable when emission pricing becomes established. The emission reduction as these farms disappear will account towards the national reduction target but this is a claytons because the intensive farms continue business-as-usual with ongoing warming emissions. Some folk may reply saying emission intensity per product output vindicates intensive land use but reality is that pastoral biological farm systems that are intensive also have a high contaminant loss that is difficult to mitigate hence problematic to downstream receiving environments.
    The HWEN recommendation is only partially acceptable noting split gas approach, farm level accountability, ability to utilise non ETS sequestration. However, some amendments are required ensuring focus upon warming emissions only, a more equitably fair pricing structure that is tiered and progressive, that there is good ability to net off within the farm, and an administrative accounting system that dovetails into existing practices to lessen overhead costs. Leadership is required to ensure there is a long term goal that is balanced with regard to food production and environmental footprint with rural communities front of mind. The Farm Plan must become centric and there must be clear identification of truly marginal lands where existing pastoral land use is clearly misplaced whether they are nitrogen leaky or sediment loss is too great. Farms like trees need to be right type, right size in the right place. The agriculture sector needs to establish for itself a goal framed up and supported by science that is relatively simple to articulate – warming neutral. This supports the Paris Agreement, it allows and promotes food production, and it then becomes irrelevant what the agricultural sectors percentage of New Zealand’s emissions are. In fact if they increased it would not be problematic if there was no associated contribution towards climate warming.

  10. david walton says:

    Keith; great you have the time, scientific expertise to reply to queries;;
    I have a couple of such and had a v good half hour chat with a v excellent Irish lass from Massey Ag Research 10 days ago;

    • Keith Woodford says:

      A vaccine and 3-NOP technology are fundamentally different. There are big challenges to getting a vaccine to work in the rumen as the antibodies struggle to get there.
      3-NOP is a feed additive but whether or not it could be formulated as a slow-release bolus is beyond my knowledge. I am sure the commercial lads and lasses will be working on that because it would be highly patentable.

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