Our consultant Phil Journeaux and Scion scientist, Tanira Kingi have produced a report covering the results of the modelling component of the Farm Systems Modelling for GHG Reduction on Māori Farms project, a project funded by the New Zealand Agriculture Greenhouse Gas Research centre (NZAGRC).
A major component of the project was to model four case study farms, as to strategies to achieve the zero-carbon act (ZCA) targets.
These are, with respect to agriculture:
(i) Reduce methane by 10% from 2017 levels by 2030, and 24-47% reduction by 2050
(ii) Reduce nitrous oxide to net zero by 2050
The key drivers of GHG emissions on-farm are:
• Amount of dry matter eaten
• Protein level of the diet
• Amount of nitrogen fertiliser applied
Correspondingly, the key scenarios modelled (via Farmax, Overseer, and Forecaster) were:
• Reduction in stocking rates, with and without improvements in per animal productivity
• Elimination of addition feed inputs into the farm via nitrogen fertiliser and/or boughtin supplements
• Changes in stock types (for the sheep & beef farms)
• Combinations of land use change, mostly forestry, to be used as an offset