ghg-inventory-1990-2013

EF 1(UREA) = proportion of direct N 2 O emissions from nitrogen input to the soil for
urea fertilisers (0.0048; table 5.5.2), and,
EF 1 = proportion of direct N 2 O emissions from nitrogen input to the soil (0.01;
table 5.5.2).
Data on synthetic fertiliser use is provided by the Fertiliser Association of New Zealand
from sales records for 1990 to 2013. Data on the percentage of urea-derived synthetic
fertiliser is sourced from the International Fertilizer Industry Association (IFA) online
database. During this time there has been a six-fold increase in elemental nitrogen applied
through nitrogen-based fertiliser, from 59,265 tonnes in 1990 to 359,412 tonnes in 2013,
and at the same time, the proportion of urea fertiliser applied has increased to over 80 per
cent of all synthetic fertiliser (figure 5.5.1).
Figure 5.5.1 Percentage of synthetic fertiliser nitrogen derived from urea, 1990–2013
100
80
60
40
20
0
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
Percentage of synthetic fertiliser N from urea
The increase in synthetic N fertiliser use since 1990 has resulted in an increase of direct
N 2 O emissions, from 217.7 kt CO 2 -e in 1990 (0.6 per cent of agricultural emissions) to
934.6 kt CO 2 -e in 2013 (2.4 per cent of agricultural emissions).
Organic nitrogen fertilisers (CRF 3.D.1.2)
Organic nitrogen applied as fertiliser in New Zealand is predominantly animal manure
that is spread after storage in manure management systems. The IPCC (2006) guidelines
recommend that non-manure components of organic N applied to agricultural soils, such
as compost, sewerage sludge and rendering waste are included under organic fertilisers.
New Zealand has commissioned a report on sources of organic waste, which include
dairy processing wastewater, compost sold to the rural sector, blood and bone fertiliser,
meat processing wastewater and sludge, grape marc from the wine industry, vegetable
processing wastewater and sewage sludge applied to land (van der Weerden et al, 2014).
The report found that these activities are not significant for New Zealand and account for
~0.024 per cent of the 2012 national total greenhouse gas emissions. No brewery waste is
applied to soils in New Zealand, as spent yeast is used in the food industry to manufacture
a yeast spread, and application of sewerage sludge to agricultural land is reported under
the Waste sector.
The majority of animal manure in New Zealand is excreted directly onto pasture, but
some manure is kept in manure management systems and is applied to soils as an organic
fertiliser (table 5.3.2). Some manure is also collected but not stored; rather, it is spread
onto pasture daily (eg, swine manure). The calculation for animal waste includes all
manure that is spread on agricultural soils, irrespective of the animal waste management
system it was initially stored in. This calculation excludes manure deposited directly by
164 New Zealand’s Greenhouse Gas Inventory 1990–2013