Agriculture Reference
In-Depth Information
Table 21.4. Contributions (%) to the different environmental impact categories of the substances
produced and resources used in the production of hemp, wheat and sugarbeet.
Substance /
resource
Impact category
Hemp
Wheat
Sugarbeet
NO 3
88.6
82.4
75.1
Eutrophication
NH 3
3.1
5.1
7.9
PO 4
3.4
5.4
7.7
NO 2
4.9
7.1
9.3
N 2 O
56.2
56.6
58.7
Climate change
CO 2
42.8
42.3
40.3
CH 4
1.0
1.1
1.0
NH 3
29.9
31.6
35.5
Acidification
SO 2
31.1
31.9
29.7
NO 2
39.0
36.5
34.8
Zn
0
0
2.4
Terrestrial ecotoxicity
Ni
70.2
67.5
65.7
Pb
3.5
4.0
3.2
Cd
26.3
28.5
28.7
Crude oil
44.7
45.8
43.7
Energy use
Natural gas
32.7
32.1
36.4
Uranium
11.4
10.6
9.0
Coal
9.3
9.5
8.8
Others
1.9
2.0
2.1
Table 21.5. The environmental impact arising from 1 ha of hemp production according to four different
production scenarios. The reference scenario is that defined in Table 21.1, the other three are defined in
Table 21.2.
Reduced
washout
Impact category
Units
Reference
Pig slurry
No-till
Eutrophication
kg eq-PO 4
20.5
23.7
20.2
11.6
Climate change
kg eq-CO 2
2,330
1,770
2,200
2,090
Acidification
kg eq-SO 2
9.8
23.5
8.5
9.8
Terrestrial
ecotoxicity
kg eq-1,4-DCB
2.3
41.9
2.3
2.3
Energy use
MJ
11,400
7,760
9,520
11,400
Surface used
m 2 /year
10,200
10,200
10,200
10,200
Note : kg eq = kg equivalent.
other crops in the context of farming practices
and pedoclimatic conditions in France.
Quantitative information on the environmental
impact of hemp production in the field is rare.
Patyk and Reinhardt (1998) present results
from an approximate LCA of hemp in
Germany. They found a similar energy require-
ment (12,300 MJ/ha) to ours (11,400). Their
findings for acidification (6.6 kg eq SO 2 ) and
for climate change (1421 kg eq CO 2 ) are lower
than our figures (9.8 and 2330, respectively).
Patyk and Reinhardt (1998) do not provide
details of their methodology, making any anal-
ysis of this difference difficult.
This study has identified important differ-
ences between crops in terms of their input
requirements and environmental impact. It has
also shown that crops with low input require-
ments have a lower impact than crops with a
greater input requirement.
While it is clear that the environmental
impact of hemp production is less significant
than that of many other crops, it is still worth
considering how they could be reduced further.
 
 
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