Agriculture Reference
In-Depth Information
tAble 18.10
estimates of u. s. and global ch
4
and n
2
of emissions from Agriculture
source
usA
world
total
(tg co2 eq.)
total
(tg co2 eq.)
% of non- co2
% of non- co2
1 N
2
O from
Agriculture
282
26
2875
32
2 CH
4
emission
a. Enteric
116
11
1712
19
b. Manure
38
3
199
2
c. Rice paddies
8
1
643
7
3 Total
443
40
5429
60
Source:
DOE, 2006; IPCC 2001.
increase due to increase in the demand to enhance food production. Furthermore,
emissions of N
2
O (from increase in fertilizer use) and of CH
4
(from increase in area
under rice paddies, livestock raising, and use of manure) may increase (Table 18.10).
These trace gasses have a high global warming potential relative to CO
2
(21 for CH
4
and 310 for N
2
O) and a positive feedback on soil degradation risks. Emission of CH
4
and N
2
O from agricultural activities is estimated at 444 Tg (Teragram, one million
metric tons) per year of CO
2
equivalent (44% of total non-CO
2
gases) for the United
States compared with 5428 Tg per year of CO
2
equivalent (60% of total non-CO
2
gases) for the world (Department of Energy [DOE] 2006).
bAsIc PRIncIPles of mAnAgement
And conseRvAtIon of soIls
Strategies of sustainable management of soil to increase food production while
restoring degraded/desertified soils include the following:
1. Minimize risks of soil erosion caused by water and wind through conver-
sion of plow tillage to no-till farming and afforestation of steep terrain and
highly erodible land
2. Enhance SOC pool by liberal use of crop residue mulch, growing cover
crops, and use of complex crop rotations and farming systems (e.g., agro-
forestry, ley farming)
3. Maintain a positive nutrient balance through integrated nutrient manage-
ment systems, including the use of manure and other biosolids, biological
nitrogen fixation, and strengthening processes of nutrient recycling
4. Improve soil structure by enhancing bioturbation through increase in activ-
ity of earthworms and microbial processes
