Abstract

Agriculture was the single largest contributor (48.1%) to total greenhouse gas (GHG) emissions in New Zealand in 2017, and sheep and beef livestock systems contributed about 40% of these emissions. A holistic assessment of the farm-scale drivers of GHG emissions is critical to identifying opportunities to reduce emissions. We used farm-scale models to estimate feed inventories, nutrient flows and GHG emissions for 60 sheep and beef farms. The range in annual GHG emissions (methane (CH4) and nitrous oxide (N2O)) was 189 to 6,362 kg carbon dioxide (CO2) equivalents per hectare, demonstrating the diversity in sheep and beef systems. As stocking rate and animal product (wool + net carcass weight) per hectare increased, GHG emissions increased, although some farms exhibited 50% higher emissions than others with similar animal product per hectare. The variation in GHG emissions across these farms indicates there is potential to reduce on-farm GHG emissions and remain productive and profitable.

KJ, Hutchinson, GM Rennie, RE Vibart, GJK Mercer, K O'Neil, AN Burtt, JM Chrystal, B Devantier, DR Smiley, AL Taylor, et al.

New Zealand Journal of Animal Science and Production, Volume 79, Palmerston North, 56-60, 2019