Skip to main content
DISCLAIMER:  Overseer Limited gives no warranties, representation or guarantees, express or implied in relation to the quality, reliability, accuracy and/or fitness for any purpose of the article. Overseer Limited expressly disclaims and assumes no liability whatsoever arising directly or indirectly from the use of, or reliance on this article.

COPYRIGHT: With the exception of user-supplied data, this Report is © 2018 Overseer Limited. All rights reserved. You may copy and distribute this Report in its entirety, as long as you do not mislead anyone as to its origin or implications, and provided you do not remove or alter the disclaimer above or this copyright notice.

2020 - van der Weerden, Noble, Luo, de Klein et al - Meta-analysis of New Zealand’s nitrous oxide emission factors for ruminant excreta supports disaggregation based on excreta form, livestock type and slope class.

Helpdesk
  • Updated

The objective of this study was to determine the most suitable urine and dung EF3 values for dairy cattle, non-dairy cattle, and sheep grazing pastures on different slopes based on a meta-analysis of New Zealand EF3 studies. 

The analysis revealed that a single dung EF3 value should be maintained, although the value should be reduced from 0.25% to 0.12%.
Furthermore, urine EF3 should be disaggregated by livestock type (cattle > sheep) and topography (flatland and low sloping hill country > medium and steep sloping hill country), with EF3 values ranging from 0.08% (sheep urine on medium and steep slopes) to 0.98% (dairy cattle on flatland and low slopes).

Following this study changes were made to the AIM / National Inventory and updates made to Overseer in model release 6.5.5, detailed here