Thursday, July 7, 2022

THE BRAIDED TRAIL: Hard hill country a good option for carbon farms

My previous article on carbon farming focused on the North Island hard hill country. If financial returns are to be the key driver of land-use, and based on a carbon price of $48 per tonne, then the numbers suggest that carbon farming on that class of country is a winner.

My previous article on carbon farming focused on the North Island hard hill country. If financial returns are to be the key driver of land-use, and based on a carbon price of $48 per tonne, then the numbers suggest that carbon farming on that class of country is a winner.

By my calculations, sheep and beef farms on this hard hill country provide an internal rate of return (IRR) of around 2%, whereas my recent estimate for carbon farming was 9.7%.

Here I extend the analysis, still using a price of $48, by looking at the easier hill country that Beef + Lamb NZ (B+LNZ) categorises as Class 4 North Island hill country. This fits between their Class 3 North Island hard hill country and the Class 5 North Island intensive finishing farms.

The Class 4 hill country totals around 1.8 million effective farming hectares, according to a B+LNZ 2020 Fact Sheet. These farms average 434 farming hectares, with the land and buildings worth about $12,400 a hectare. The average return on total capital invested, which includes livestock and machinery, is around 2.5%, but this still has to pay the owner’s drawings.

In general, trees don’t mind too much whether they are on medium or steep hills. It is all about moisture and light interception. Accordingly, the official Look-up Tables (LUTs) setting the allocation of carbon credits do not discriminate by slope or aspect.

Land area is always measured as the equivalent flat area, as if all the land was bulldozed to a flat condition. Accordingly, a steep slope will have more sloping surface area than a flat area, but the light interception per square metre of that sloping surface area will be less.

In assessing the economics of carbon farming on this land and using the official Schedule 6 LUTs, there is only one important change needed to the figures I recently used for the hard hill country. That change is that land and buildings for this more moderate land are valued by B+LNZ at $12,400 a hectare, rather than the $8100 for the hard hill country. I also increased the land rates from $23/ha to $32/ha, but the overall effect of that is trivial.

So here is the comparison for B+LNZ Class 4 hill country: under carbon forestry, the estimated IRR is 7.0%, compared to about 2.5% under sheep and beef.

In response to my last article, I received numerous emails both from foresters, farmers and others. Some of the points they were making apply to both hard and more moderate hill country, and I will respond to key points here.

The risk of disaster

The calculations I have reported so far do not include allowance for disaster by fire, pests or disease. What happens to the carbon credits in that situation?

The disaster regulations are not necessarily set in concrete yet, but my understanding is that if disaster occurs, then carbon credits take a ‘holiday’. The forest owner does not have to repay anything, but there are no more credits until the forest recovers to its previous stage, with this including replanting if necessary.

As an example, I analysed a scenario whereby disaster strikes after eight years, and that it then takes another 10 years to recover to the previous state. On the hard hill country, that reduced the IRR from 9.7% down to 6.9%. On the moderate hill country, it dropped the IRR from 7.0% % down to 4.9%. In both cases, it extended the claimable credits out further into the future, with the 50 years of credits still claimable but now over a longer period.

Delaying the disaster until the forest is 20 years of age has a lesser effect. For example, on the easier hill country and assuming the same recovery period of 10 years, the IRR now becomes 5.9% rather than 4.9%. This smaller effect may seem surprising, but it is caused by the carbon credits having already substantially exceeded the initial investment by the time of the disaster. Accordingly, for carbon forestry and in marked contrast to production forests, a late-stage disaster is a lesser disaster from a purely financial perspective.

Extending the benefits beyond 50 years

In my previous article, I stated that the benefits were only valued out to 50 years because that is as far as the LUTs extend. However, an MPI specialist confirmed in a recent webinar to members of the NZ Institute of Primary Industry Management, which I attended, that these tables will be extended once more data become available. 

Based on discussions with foresters, I have assumed as one scenario that the forests will continue to earn credits for another 30 years through to 80 years at 20 tonnes per annum a hectare. That is sufficiently far off that those additional years have only a minor effect on the IRR, raising it by only around 0.1%. This is trivial in terms of the overall financial returns.

The benefits of scale

The advice I have received from foresters has emphasised that the LUTs are conservative. However, for forests of less than 100ha, I am told these are the numbers that must be used. 

In contrast, for forests larger than 100ha, the numbers to be used must come from surveys by professionally accredited forest surveyors. This obviously comes with a cost, but the additional benefits on well-managed and favourable sites can be considerable.

One forester advises me that he recommends a permanent forest should be planted at 1600 trees a hectare, instead of the normal 1000. Also, there is no need to thin or prune such a forest, and this gives a further advantage over the Schedule 6 LUT numbers. The upside from doing things this way is considerable. It is a big advantage for the big boys.

What happens if the carbon price crashes?

I don’t expect that to happen. But if it did – let’s say that it dropped to $2, which is where it was for several years earlier this century. The financially optimal investment strategy would then be to cut down the forest and repay the credits at that miniscule price of $2, and then change the land-use back to whatever had become more profitable. This is exactly what happened some 10 years ago with big areas in the Central North Island, and also to a lesser extent elsewhere, with the most profitable alternative land-use being dairy.

Pulling it all together

If financial returns were all that mattered, then it is clear that current carbon prices are sufficient to justify turning much of the North Island sheep and beef land into carbon forests. However, financial returns are not everything.

To explain that a little more, the commercial world operates on the basis of maximising profits within a regulatory environment. It is up to the regulatory environment to take other things into account. Those issues include the need for export earnings, with carbon trading being essentially an internal market. There are also big issues as to whether locking up land in this way is actually the right moral thing to do.

Those issues are too big to address here. However, I am likely to have more to say about those issues in the near future. 

The big message right now is that carbon farming is becoming a game-changer in New Zealand rural land-use. It is where the money lies. We need to think carefully about the full implications thereof.


Keith Woodford was Professor of Farm Management and Agribusiness at Lincoln University for 15 years through to 2015. He is now Principal Consultant at AgriFood Systems Ltd. He can be contacted at Previous articles can be found at

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