Developing revised emission factors for nitrous oxide emissions from agricultural pasture treated with nitrification inhibitors

Appendix II - Tables A.1 – A.9

Table A.1. Dairy cattle urine EF3 (fraction of applied N evolved as N2O, duration of study in days) measurements made at NzOnet trial sites located in three regions (Barton et al., 2000; de Klein et al., 2003, 2004; Sherlock et al., 2003a,b). These data represent analyses of an estimated 30,000 gas samples collected over 4 years (2000 – 2003). No data is abbreviated as n.d.

Season Spring Summer Autumn Winter
Well-drained soils by region
Otago n.d. 0.0146, 202 n.d. 0.0090, 149
Canterbury n.d. n.d. 0.0050, 224 n.d.
Waikato 0.0122, 91 0.0007, 253 0.0064, 163 0.0090, 146

Imperfectly-drained soils by region

Canterbury 0.0037, 91 0.0020, 262 0.0330, 224 n.d
Poorly-drained by region
Otago 0.0295, 69 0.0058, 202 0.0260, 152 0.0090, 149
Waikato 0.0261, 91 0.0075, 253 n.d. 0.0270, 146

Table A.2. Dairy cattle dung EF3 (fraction of applied N evolved as N2O, duration of study in days). No data is abbreviated as n.d.

Season Spring Summer Autumn Winter
Well-drained soils by region
Waikato 0.0024, 91 n.d. n.d. n.d.
Otago n.d. n.d. n.d. 0.001, 149
Imperfectly-drained soils by region
Canterbury 0.0017, 91 0.0021, 262 n.d. n.d.
Waikato 0.0043, 91 n.d. n.d. n.d.
Otago n.d. n.d. n.d. 0.001, 149

Table A.3. Sheep urine and dung EF3 (fraction of applied N evolved as N2O, duration of study in days) measurements made at the Otago site. No data is abbreviated as n.d.

Season Spring Winter
Well-drained soil
urine 0.0020, 69 0.0030, 149
dung 0.0001, 69 n.d.
Poorly-drained soil
urine 0.0010, 69 0.0020, 149
dung 0.0000, 69 n.d.

Table A.4. Method 1 pastoral soils nitrous oxide (N2O) emissions. Nitrogen (N) application to these soils is shown as urine and dung excreta deposited by grazing animals and fertiliser (80 % of total sold). Year 2010 represents an average for the Kyoto Protocol Commitment Period 1. “Change” denotes a change of total from the Kyoto Protocol base year of 1990 to years thereafter including 2004 and 2010. A tonne is equivalent to 106 grams (g), while Gg means 109 g. The N2O emissions computation based on the quantity of N applied to soils includes multiplication by the ratio of molecular weights (44/28).

N source N Excreta
(tonnes)
EF3 Gg N2O
1990 2004 2010 1990 2004 2010
Dairy cattle              
Urine 245800 418480 451612
Dung 92118 150184 182149
Sub total 337918 568664 633761 0.01 7.63 12.84 14.31
Change 0         5.21 6.68
               
Beef cattle              
Urine 201007 219024 205502
Dung 103088 112328 107763
Sub total 304095 331352 313265 0.01 6.57 7.16 6.77
Change           0.59 0.20
               
Sheep              
Urine 481942 391892 421415
Dung 247168 200985 220985
Sub total 729110 592877 642400 0.01 15.75 12.81 13.88
Change           -2.94 -1.87
               
Deer              
Urine 15963 32620 29220
Dung 8187 16729 15323
Sub total 24149 49349 44543 0.01 0.52 1.07 0.96
Change           0.55 0.44
               
N source N fertiliser
(tonnes)
EF1 Gg N2O
  1990 2004 2010   1990 2004 2010
Fertiliser 41429 276192 322967 0.01 0.77 5.10 5.96
Change           5.41 6.49
               
Grand total         31.24 38.98 41.88
Change           7.74 10.64

Table A.5. Method 1 pastoral soils nitrous oxide (N2O) emissions inventories with annualised DCD emission factors for all animal classes. For these two scenarios, DCD was applied as recommended to all land grazed by dairy cattle, beef cattle, sheep and deer (denoted All land) or the land grazed by dairy cattle (denoted Dairy land).

N source Gg N2O (All land) Gg N2O (Dairy land)
1990 2004 2010   1990 2004 2010
Dairy              
Urine  
Dung  
sub total 7.63 9.24 10.29   7.63 9.24 10.29
Change   1.61 2.66     1.61 2.66
               
Beef              
Urine  
Dung  
sub total 6.57 5.13 4.85   6.57 7.16 6.77
Change   -1.44 -1.72     0.59 0.20
               
Sheep              
Urine  
Dung  
sub total 15.75 9.19 9.95   15.75 12.81 13.88
Change   -6.56 -5.80     -2.94 -1.87
               
Deer              
Urine  
Dung  
sub total 0.52 0.76 0.69   0.52 1.07 0.96
Change   0.24 0.17     0.55 0.44
               
N source    
  1990 2004 2010   1990 2004 2010
Fertiliser 0.77 3.67 4.29   0.77 3.95 4.62
Change   2.90 3.52     3.18 3.85
               
Grand total 31.24 27.99 30.07   31.24 34.23 36.52
Change   -3.25 -1.17     2.99 5.28

Table A.6. Method 2 calculations are done separately for October – April when no DCD was used and May – September when DCD is used. The nitrogen applied to soils as excreta is an aggregation of urine and dung. Consequently, though not shown explicitly in Table A.5 because only annual values are given there, the calculations for October – April that are shown here yield the same figures as would have been obtained using method 1. For May – September, a second set of revised values are used for EF3(PRP) and EF1 and FracLEACH. This nitrous oxide (N2O) emissions inventory was calculated with DCD applied as recommended to the land area grazed by dairy cattle.

N source Gg N2O (Oct – Apr) Gg N2O (May – Sep) Gg N2O (year)
1990
No DCD
2004
No DCD
2010
No DCD
1990
No DCD
2004
DCD used
2010
DCD used
1990
No DCD
2004
DCD used
2010
DCD used
Dairy                  
Urine                  
Dung                  
sub total 4.67 7.93 8.84 2.96 1.58 1.76 7.63 9.51 10.60
Change   3.26 4.17   -1.38 -1.2   1.88 2.97
                   
Beef                  
Urine                  
Dung                  
Sub total 3.75 4.08 3.86 2.82 2.78 2.62 6.57 6.86 6.48
Change   0.33 0.11   -0.04 -0.2   0.29 -0.09
                   
Sheep                  
Urine                  
Dung                  
Sub total 10.17 8.38 9.08 5.58 4.00 4.33 15.75 12.38 13.41
Change   -1.79 -1.09   -1.58 -1.25   -3.37 -2.34
                   
Deer                  
Urine                  
Dung                  
Sub total 0.32 0.67 0.61 0.20 0.36 0.32 0.52 1.03 0.93
Change   0.35 0.29   0.16 0.12   0.51 0.41
                   
Fertiliser       0.77 2.03 2.37 0.77 2.03 2.37
Dairy 0 0 0 0.67 1.430 1.670 0.67 1.43 1.67
Beef & Sheep 0 0 0 0.10 0.60 0.70 0.10 0.60 0.70
Change   0 0   1.26 1.60   1.26 1.60
                   
Grand total 18.91 21.06 22.39 12.33 10.15 10.7 31.24 31.21 33.09
Change                  

Table A.7. Method 3 calculations are done separately for October – April and May – September. The nitrogen applied to soils as excreta is disaggregated into urine and dung, so so a third set of revised values for EF3(PRP), EF1, and FracLEACH are used for each of the two periods. This nitrous oxide (N2O) emissions inventory was calculated with no DCD applied to soils.

N source Gg N2O (Oct – Apr) Gg N2O (May – Sep) Gg N2O (year)
1990 2004 2010 1990 2004 2010 1990 2004 2010
Dairy                  
Urine 2.33 3.96 4.27 2.69 4.46 4.82 5.02 8.42 9.09
Dung 0.69 1.18 1.40 0.44 0.73 0.86 1.13 1.91 2.26
sub total             6.15 10.33 11.35
Change               4.18 5.20
                   
Beef                  
Urine 1.76 1.91 1.80 2.41 2.63 2.46 4.17 4.54 4.26
Dung 0.53 0.58 0.56 0.40 0.44 0.42 0.93 1.02 0.98
Sub total             5.10 5.56 5.24
Change               0.46 0.14
                   
Sheep                  
Urine 2.81 2.32 2.49 1.54 1.23 1.32 4.35 3.55 3.81
Dung 0.97 0.80 0.87 0.53 0.42 0.46 1.50 1.22 1.33
Sub total             5.85 4.77 5.14
Change               -1.08 -0.71
                   
Deer                  
Urine 0.21 0.44 0.40 0.13 0.26 0.23 0.34 0.70 0.63
Dung 0.05 0.10 0.09 0.03 0.06 0.05 0.08 0.16 0.14
Sub total             0.42 0.86 0.77
Change               0.44 0.35
                   
                   
Fertiliser                  
Dairy 0.00 0.00 0.00 0.87 5.83 6.82 0.87 5.83 6.82
Beef & Sheep 0.00 0.00 0.00 0.13 0.83 0.97 0.13 0.83 0.97
                   
Grand total             18.52 28.18 30.29
Change               9.66 11.77

Table A.8. Method 3 calculations are also done separately for October – April when DCD is not used and for May – September when DCD is used. The nitrogen applied to soils as excreta is disaggregated into urine and dung, so a third set of revised values for EF3(PRP), EF1, and FracLEACH are used for each of the two periods. This nitrous oxide (N2O) emissions inventory was calculated with DCD applied to the land area grazed by dairy cattle.

N source Gg N2O (Oct – Apr) Gg N2O (May – Sep) Gg N2O (year)
1990 2004 2010 1990 2004 2010 1990 2004 2010
Dairy                  
Urine 2.33 3.96 4.27 2.69 1.78 1.92 5.02 5.74 6.19
Dung 0.69 1.18 1.40 0.44 0.61 0.72 1.13 1.79 2.12
sub total             6.15 7.53 8.31
Change               1.38 2.16
                   
Beef                  
Urine 1.76 1.91 1.80 2.41 2.63 2.46 4.17 4.54 4.26
Dung 0.53 0.58 0.56 0.40 0.44 0.42 0.93 1.02 0.98
Sub total             5.10 5.56 5.24
Change               0.46 0.14
                   
Sheep                  
Urine 2.81 2.32 2.49 1.54 1.23 1.32 4.35 3.55 3.81
Dung 0.97 0.80 0.87 0.53 0.42 0.46 1.50 1.22 1.33
Sub total             5.85 4.77 5.14
Change               -1.08 -0.71
                   
Deer                  
Urine 0.21 0.44 0.40 0.13 0.26 0.23 0.34 0.70 0.63
Dung 0.05 0.10 0.09 0.03 0.06 0.05 0.08 0.16 0.14
Sub total             0.42 0.86 0.77
Change               0.44 0.35
                   
                   
Fertiliser                  
Dairy 0.00 0.00 0.00 0.87 5.83 6.82 0.87 5.83 6.82
Beef & Sheep 0.00 0.00 0.00 0.13 0.83 0.97 0.13 0.83 0.97
                   
Grand total             18.52 21.68 22.92
Change               3.16 4.40

Table A.9. Using the 3 methods to calculate pastoral soils nitrous oxide (N2O) emissions, two scenarios are shown whereby either no land was treated with DCD (no DCD) or all of the land grazed by dairy cattle (denoted Dairy land) was treated with DCD as recommended.

Method Gg N2O (no DCD) Gg N2O (Dairy land)
1990 2004 2010 1990 2004 2010
1 31.24 38.98 41.88 31.24 34.23 36.52
Change   7.74 10.64   2.99 5.28
             
2 31.24 38.98 41.88 31.24 31.21 33.09
Change   7.74 10.64   -0.03 1.85
             
3 18.52 28.18 30.29 18.52 21.68 22.92
Change   9.66 11.77   3.16 4.40

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