Owen Jennings: Farmers Deserve Better

My first farm was mainly old sand dunes with thirty to fifty mm’s of good soil on the tops.  We farmed cows and pigs, collected the manure and spread it on the ridges.  Within a few years we built the soil humus to 200 to 300mm’s.  We called it humus or topsoil. Today, we call it “carbon”.

In fact, we built thousands of tonnes of carbon all taken from atmosphere.  It was a ratio of 8:1 – it took eight tonnes of CO2 from the atmosphere to build one tonne of carbon in the soil. We call it ‘sequestering’.  It all happens via photosynthesis and the carbon cycle you learnt at school.  CO2 in the atmosphere gets taken in by plants, animals eat plants and burp methane back into the atmosphere that eventually becomes CO2 that the next lot of plants need.

The challenge arises from the burped methane being stronger than the CO2 taken in by the plants.

Strangely, this is still happening today.  All around the country farmers are steadily building carbon into their soils.  I say ‘strangely’ because you never hear any commentary on this highly commendable work.  What you do hear is how much methane and CO2-equivalent farmers are “spewing into the atmosphere”. Little is said about the other side of the equation.

Dig around and you will find that huge areas of our hill country grassland soils (which occupy about 4 million hectares or 38% of New Zealand’s grazed land) gain carbon at a rate of up to 0.6 tonnes/ha/year.  Do some maths and that means some 2.5 million tonnes of carbon is being built by just one section of our farmland.  To build that carbon takes 20 million tonnes of CO2 from the atmosphere using the established 8:1 ratio.

But that is only part of the story.  Carbon not only stays in the soil, it ends up in meat, wool and milk and in on-farm vegetation, trees, riparian plantings etc.  Complicating it all further is the fact that some soils, like our Waikato peats, have a stable or falling level of carbon.  Obtaining accurate figures is difficult because we haven’t done the research work fully enough, despite the clear need to do so.  Too much research is ill-directed.  Too much focus on symptoms, not causes.  Too much irrelevant science on ‘fluff and puff”, hobby pursuits and too little on foundational issues.

What does the overall equation look like?  Ministry of the Environment tells us that our sheep and cattle produced 30 million tonnes of CO2-e.   The IPCC stated in its AR6 report that in a situation like we have in New Zealand where methane levels are stable or falling that the CO2-e measurement overstates the actual warming potential by 300 – 400% so that 30 million tonnes is actually only 7 to 10 million tonnes of warming potential.

So, 38% of our grassland all by itself, is sequestering far more carbon than we produce in methane.  Even if the figures are rough – the differences are stark.

And we are busting our gut trying to breed low methane sheep and sending armies of bureaucrats to measure every farmer’s emission profile.  Spending levy money and taxpayer’s money on a useless exercise.

How about some honesty and integrity?  How about focusing on the most recent science that tells us our ruminant methane emissions are not a problem?  How about checking that science carefully – not some science that is now seven years old.  How about putting a much greater effort into what is happening with sequestration?  Farmers deserve better.

Owen Jennings, a former Member of Parliament and President of Federated Farmers, maintains a keen interest in ensuring agricultural policies are sensible and fit for purpose.