The notion that New Zealand’s soils may not be suitable for storing carbon is being challenged by dairy farming group Southern Pastures.
The company has worked with Manaaki Whenua Landcare Research to measure the baseline of how much carbon is within the soil across the company’s 19 farms.
These figures will be monitored in five years’ time to determine if the company’s farming practices have increased the amount of carbon in the soil.
The practices include low tillage, planting deep-rooted crops, and introducing dung beetles, along with increasing biodiversity and native plantings.
The study will also challenge the convention among scientists that the likelihood of soil carbon sequestration in New Zealand is small because the country’s soils already contain relatively high levels of carbon.
“While that may be true for some farms and some soil types, we don’t believe it can be generalised across the country,” Southern Pastures executive chair Prem Maan said.
“Science is about setting up a hypothesis and setting up an experiment to test it and our view is that we can sequester more carbon and to test our theory, that’s what we are doing.
“We owe it to ourselves to test it.”
He said NZ farmers need to be given the option of soil carbon sequestration because it will help incentivise and reward climate change mitigation.
Maan said dung beetles in particular provide a huge number of environmental benefits that are underappreciated.
The beetles drag cow dung underground and, in the process, aerate the soil and reduce the likelihood of the dung decaying above the ground and releasing greenhouse gases, and of the nutrients running off into waterways.
Observations on Southern Pastures farms show the work the beetles do, he says.
“What we do from time to time is take a spade and dig into the soil and see where the beetles are and how far down the dung goes.”
The insects’ work also allows for pastures to recover much faster when grazed. Studies have shown increases in above-ground biomass and protein levels along with greater root plant depth.
NZ research showed that farms with dung beetles during flood events had 81% less overland flow and 91% less erosion.
Southern Pastures has also achieved Toitū carbon reduce certifications for its farms across NZ.
Maan said it means Southern Pastures is on a path to achieve carbon neutrality on all its dairy farms through its farming practices, where possible.
Southern Pastures’ 19 dairy farms and one support farm are in Waikato and Canterbury and the company is the owner of premium dairy brand Lewis Road Creamery and wholesale business NZ Grass Fed Products.
“We’ve made a decision to refuse to utilise offsets generated by external exotic forests to achieve our zero carbon ambitions,” Maan said.
“There aren’t enough pine trees in the world to cancel out extractive and polluting human industries. If we want to continue producing healthy food and have a liveable planet, the way we farm must change, so we live within our means.”