New Zealand’s beef and sheep farms are practically carbon neutral, says an independent study looking at sequestration in vegetation.
An Auckland University of Technology project has concluded that farms can have 63-118% of their on-farm agricultural emissions offset when accounting for carbon sequestration.
Currently, woodland vegetation on NZ (New Zealand) farms does not qualify for the Emissions Trading Scheme because it is not classed as forest.
Sam McIvor, chief executive officer of Beef and Lamb New Zealand – the country’s red meat levy board – said it’s only right that farmers get credit for sequestration if they face a price for agricultural emissions.
Dr Bradley Case, a senior lecturer at the university, said there is a “strong case” for farmers to get credit for the sequestration that takes place on their farms.
He said: “This research not only builds understanding of the overall greenhouse gas contribution of the sheep and beef sector, but will help inform the development of policy, and further reinforce the outstanding biodiversity on sheep and beef farms.”
Dr Case stressed that, importantly, net carbon emissions from soil were assumed to be net neutral, so there could be scope for even greater sequestration to be happening.
He added: “While there is fairly good information about soil carbon stocks, there is not good data about yearly changes in soil sequestration, and the science on this is still in development.”
Useful for the UK too
Dr Jude Capper, livestock sustainability consultant, said that the same message was true for UK farmers.
Hedgerows, trees and woodlands, manure and trading action of grazing livestock all offsetting livestock’s greenhouse gas emissions through carbon sequestration, said Dr Capper.
“What we need now is better science and data available so that we can accurately assess the extent of carbon offsetting by sequestration on every farm and across the industry.”
“When we assess carbon neutrality, it’s essential to include both the greenhouse emissions (e.g. enteric methane, nitrous oxide from manure, carbon dioxide from fossil fuels, etc) and the ways in which agriculture can sequester carbon into plants and soil.
Dr Capper gave some tips on how to improve a farm’s carbon footprint:
- Make small changes to impact efficiency – a 10-15% lift in productivity would have environmental and economic benefits
- Finishing cattle earlier, getting more cows in calf each year, weaning more calves per 100 cows bulled, reducing heifers calving age to 24 months can all help
- Mob grazing, maximising manure inputs, managing trees and hedgerows for healthier growth and planting more woodland and hedges all have positive impacts. Carbon accumulation in soil plateaus at about 25 years and so these techniques can help.
- Absolute greenhouse gas emissions from New Zealand beef and sheep has dropped 30% since 1990.
- 295m kilotonnes (Kt) of carbon is held in all above- and below-ground carbon stocks.
- 15% of the average New Zealand farm is woody vegetation, varying from 5-37%.
- The average woody carbon stock of a New Zealand farm is 4.5Kt of carbon.
The report, which was commissioned by Beef and Lamb New Zealand, called for a standard method for calculation of sequestration and carbon stocks below and above ground by looking at vegetation in more detail, such as age, condition and species of on-farm vegetation.
It also called for a spatial map of farmland for future greenhouse gas and sequestration budget calculations and for scenario planning on farm or landscape level.
Four questions for the UK industry
Farmers Weekly asked National Sheep Association chief executive Phil Stocker how the UK sheep industry compares.
1 How does the UK sheep sector compare to NZ?
“We would be exactly the same given that our sheep industry is predominantly grass fed and pastoral in nature. In fact our grassland has a low dependence on artificial inputs and has a high proportion of its area in agri environment schemes that promote the environmental management of hedges and trees. We are seeing new hedges planted, smaller fields in some cases and agro-forestry approaches being introduced.
“Importantly, this research work is valuable to us in that it measured the carbon held in vegetation and farm habitats in the same way as the tree industry has measured carbon held in woodland and forests.:
“Recent research from Rothamstead has shown that the soil quality beneath our grasslands is equal to the soil quality in woodlands – the missing bit of the equation has been the role of vegetation with that work never having been done for grassland.
“For livestock based grassland management the situation is more complex because it’s not just about the vegetation but also the wool, the leather, and of course the meat and how that converts to carbon when we eat it. This NZ work is a really helpful part of the jigsaw and it’s just as relevant to the UK as it is to NZ.”
2 What can UK farmers learn from this?
“That the carbon footprint of our grazed livestock systems is nowhere near as bad as it’s been painted in the past. We can all make efficiency improvements that reduce our carbon footprint further (through reducing losses, improving health and efficiency, improving soil management) but essentially most of our grazed sheep production is actually good for our environment.”
3 To your knowledge is the government now including carbon sequestration in life cycle analysis?
No. There is a better awareness but at a Govt level and via the IPCC (Intergovernmental Panel on Climate Change) carbon sequestration is not being adequately considered.
4 Has there been work done or is there work planned looking at carbon sequestration in sheep? (Farm Carbon Toolkit, Agrecalc, Cool Farm Tool).
“Yes, these tools do attempt to consider sequestration – but a further problem we have is that as far as I’m aware they (and the IPCC) still use the GWP (Global Warming Potential) figures, rather than the GWP* figures that came from Oxford University (that showed methane has a far shorter life cycle than N2O and CO2 and therefore doesn’t build and accumulate to the same extent in the atmosphere).”