New Zealand Can Lead the World in Reducing Emissions
An international soil scientist has spelt out the way New Zealand can meet part of its commitment to reducing carbon
dioxide in the atmosphere.
The release of CO2 significantly contributes to climate change. However Dr John Baker says it can be achieved without
radical changes to farming practices. “It just requires a refinement of what’s being done now,” he says.
The New Zealand Government, at the Paris Climate Change conference, has agreed to reduce the discharge of greenhouse
gases (GHG) but is struggling to do so.
Dr John Baker says New Zealand has more potential to remove millions of tonnes of CO2 from the atmosphere, than most
other countries in the world because we have a high land-to-emissions ratio.
“It involves our farm crops and pastures utilising sunshine, which we have in abundance, to take CO2 out of the
atmosphere by photosynthesis and retain it in the ground undisturbed,” he says.
“In doing so, New Zealand’s one million hectares of newly established crops and pastures each year hold the key to
reversing a significant portion of its GHG emissions by converting it into soil carbon which, in turn, increases crop
and pasture yields.”
Dr Baker explains it can be achieved through New Zealand farmers learning how to manipulate the soil to their, and their
country’s, advantage.
“The remedy is to absolutely minimise any form of soil disturbance and stop burning crop residues, both of which release
massive quantities of carbon into the atmosphere,” he says.
Dr Baker explains there’s a far better method of seeding that not only retains CO2 in the soil but actually adds new
carbon each time a new crop is grown. “I’m talking about a unique form of ‘no-tillage’, distinctive from any others,
known as low disturbance, no-tillage which has already shown spectacular results in New Zealand and around the world.”
Dr Baker says the challenge is to stop our farmers’ love affair with disturbing the soil. All disturbance oxidises
organic matter into CO2 which is the most common GHG.
Cultivation (ploughing) and many simple forms of no-tillage can’t work through residue, which is the decaying matter
left on top of the ground after a crop is harvested.
So instead, farmers burn it which is the worst thing they can do. They release the carbon, which otherwise feeds the
earthworms and microbes and enriches the soil’s health and its water holding capacity he says.
“New Zealand gets enough water and sunshine but these two commodities don’t always arrive at the best times of the year.
You can’t store sunshine but you can store water. So it’s essential New Zealand farmers learn to store more water in
their soils for when it’s needed,” he says.
“Low disturbance no-tillage does this by recapturing carbon from the atmosphere through photosynthesis and retaining it
in the soil. It’s a win-win.”
Dr Baker explains that conventional tillage (or cultivation) has stripped the organic matter from the soil over hundreds
of years. And inferior methods of conservation tillage, now being utilised in 37% of our annual seeding, only go part
way to reversing that trend.
He points out that New Zealand farmers regularly grow useful arable and forage crops and pastures, but when low
disturbance no-tillage is used, “no-one in the world can match us.”
The evidence is regularly achieved around New Zealand with a 16.8 t/ha winter wheat crop grown by FAR in Geraldine or 11
t/ha spring barley crops and 20 t/ha turnip crops that several farmers around the country have recorded.
“Organic matter is the silver bullet. If you retain crop residues and leave the soil undisturbed, you increase soil
organic levels and retain the soil’s water storage capacity,” Dr Baker says.
“To do this you need a special combo-disc-and-tine type ‘no-tillage’ opener that penetrates through the crop residue or
vegetation on top of the soil and creates humidity-retaining seed slots beneath it without leaving the seeds embedded in
the residue itself.”
Such low disturbance, no-tillage drills sow the seed and fertiliser in separate bands at the same time through any
amount of surface residues. Done properly the process traps the humidity, preserves the earthworms and micro-organisms,
increases yields and largely prevents carbon from escaping into the atmosphere.
“Because plants absorb carbon from the atmosphere through photosynthesis this is one way of ensuring that more carbon
goes into the soil than out. The method, based on university research, addresses climate change and increases the amount
of food that the world produces at the same time,” Dr Baker comments.
“It’s also a win-win for both farmers and politicians who signed the Paris agreement,” he says. “The technology mimics
nature and the sooner New Zealand farmers and decision makers realise this, the sooner they’ll start to meet their
conservation objectives.”
Dr Baker emphasises that if New Zealand universally adopted ‘low disturbance, no-tillage’, it would reduce 11% of the
GHGs that the whole of New Zealand emits and at least a quarter of agriculture’s emissions alone.
“That’s an incredible saving potential that is greater than almost any other country on earth except Australia, and the
good thing is that New Zealand is where the Cross Slot® technology was invented,” he comments.
ends