Agriculture Reference
In-Depth Information
Table 8.5
Estimates of global ammonia emissions
(
Tg N year
−
1
)
from different sources
Reference
Schlesinger and
Hartley (1992)
Dentener and
Crutzen (1994)
Bouwman
et al
.
(1997)
Animals
Cattle including buffaloes
19.9
14.2
14.0
Pigs
2.0
2.8
3.4
Horses, mules, asses
1.8
1.2
0.5
Sheep, goats
4.1
2.5
1.5
Poultry
2.4
1.3
1.9
a
Wild animals
2.5
0.1
Total animals
32.3
24.5
21.7
Others
Synthetic fertilizers
8.5
6.4
9.0
Undisturbed ecosystems
10
5.1
2.4
Crop plants
—
—
3.6
Biomass burning
5
2.0
5.7
Human excrement
4
—
2.6
Sea surface
13
7.0
8.2
Fossil fuel combustion
2.2
—
0.1
Industry
—
—
0.2
Total emission
75
45.0
53.6
a
Included in undisturbed ecosystems.
Source
: Bouwman
et al
. (1997). Reproduced by permission of American Geophysical Union.
Table 8.6
Global use of nitrogenous fertilizers and corresponding NH
3
emissions based
on empirical emission factors for different fertilizer types and uses
Emission
(
Gg N year
−
1
)
Type of nitrogenous
Global use
fertilizer
(
Tg N year
−
1
)
Temperate
Tropical
Total
Urea
29.2
1632
4137
5769
Ammonium bicarbonate
9.5
802
1189
1991
Ammonium nitrate
8.2
25
141
166
NPK
6.6
40
219
259
Anhydrous ammonia
5.2
18
190
209
Nitrogen solutions
4.2
11
93
104
Calcium ammonium nitrate
4.1
9
72
82
Ammonium phosphates
3.7
35
113
147
Ammonium sulfate
2.6
34
169
203
Others
3.7
20
85
105
Total
77.0
2626
6409
9035
Source
: Bouwman
et al
. (1997). Reproduced by permission of American Geophysical Union.
et al
., 1997). Seventy per cent of the emission is from developing countries in
the tropics; of this 65% is from urea and 19% from the volatile hydrolysis prod-
uct of urea, ammonium bicarbonate, which is widely used in China. Based on
data for rice area and yield by country (IRRI, 2002), the approximate relation
