Agriculture Reference
In-Depth Information
Table 8.4a
Estimates of the global nitrous oxide budget (Tg N year
−
1
; mean and range)
from different sources and sinks
Reference
Olivier
et al
.
(1998)
Mosier
et al
., (1998a);
Kroeze
et al
., (1999)
Prather
et al
.
(2001)
Base year
1990
1994
1990s
Natural sources
Ocean
3.6
(2.8-5.7)
3.0
(1-5)
Atmosphere (NH
3
oxidation)
0.6
(0.3-1.2)
0.6
(0.3-1.2)
Tropical soils
Wet forest
3.0
(2.2-3.7)
Dry savanna
1.0
(0.5-2.0)
Temperate soils
Forests
1.0
(0.1-2.0)
Grasslands
1.0
(0.5-2.0)
All soils
6.6
(3.3-9.9)
Anthropogenic
Agricultural soils
1.9
(0.7-4.3)
4.2
(0.6-14.8)
Biomass burning
0.5
(0.2-0.8)
0.5
(0.2-1.0)
Industrial sources
0.7
(0.2-1.1)
1.3
(0.7-1.0)
Cattle and feedlots
1.0
(0.2-2.0)
2.1
(0.6-3.1)
6.9
Total source
14.9
(7.7-24.5)
17.7
(6.7-36.6)
Sinks
To t a l s i nk
(stratosphere)
12.3
(9-16)
12.6
Implied total source
a
16.2
16.4
a
Total sink
atmospheric increase.
Source
: adapted from Prather
et al
. (2001).
+
Table 8.4b
Estimates of the global NO
x
(
NO
+
NO
2
)
budget (Tg N year
−
1
; mean and range)
Base year 1990
Natural sources
All soils
5.5
(4-12)
Lightning
12.2
(2-20)
NH
3
oxidation in atmosphere
0.9
(0-1.6)
N
2
O destruction in stratosphere
0.7
(0.4-1)
Anthropogenic
Fossil fuel combustion
23.4
(13-31)
Biomass burning
7.7
(3-15)
Total source
50.4
(22-81)
Source
: Olivier
et al
. (1998).
in southern China is to apply large quantities of nitrogen fertilizer early in the
growing season to stimulate crop growth and production of tillers, and to then
abruptly drain the soil to arrest tillering by driving off nitrogen through nitrifi-
cation-denitrification. Here and in other systems, large emissions of N
2
Oareto
