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TOPIC 2: NEW ZEALAND
 

REVIEW REPORT FOR NEW ZEALAND

B.  Key categories
1.  Enteric fermentation – CH4

65. New Zealand has estimated CH4 emissions from enteric fermentation using a country-specific model based on sound scientific principles (Clark et al. 2003).  The model estimates the total dry matter (DM) intake for several different subgroups of dairy cattle, beef cattle, sheep, and deer and multiplies the DM intake with a country-specific CH4 EF, taking into account changes in productivity.  For estimation of CH4 emissions from horses, goats, pigs, and poultry New Zealand used tier 1 methods.  Of these animals only goats are ruminants.  For goats New Zealand uses a value of 9 kg CH4/head/yr, although it is stated in the NIR that it has used the IPCC default value (5 kg CH4/head/yr).  New Zealand is recommended to verify its choice of EF in its next submission.

2.  Manure management – CH4

66.  For the estimation of CH4 emissions from manure management New Zealand uses a tier 2 method.  The whole time series has been recalculated, as previously New Zealand used the tier 1 method.  The effect of the change is an increase in the emissions of CH4 of 32.1 per cent for year 2003.  The change in EF for manure deposited on grassland is well documented in the NIR.  Only 5 per cent of the manure from dairy cattle is managed and because of the relatively small population of pigs in New Zealand only small amounts of pig manure are handled.  As a consequence, CH4 emissions from this source are very low compared with other countries.  The ERT believes that estimated emissions from this category are of a good quality.

3.  Direct soil emissions – N2O

67. The total amount of mineral fertilizer used in 2004 is 310.7 Gg N.  This figure is based on data from the New Zealand Fertiliser Manufacturers Research Association and in accordance with the data reported by the International Fertilizer Industry Association.  The total fertilizer consumed in New Zealand has increased six fold since 1990, while the area of annual crops has remained about the same.  The major part of the fertilizer is applied to grassland.