Agriculture Reference
In-Depth Information
The substitution of mineral fertilizers with pig
slurry is of limited interest. A reduction in the
impacts arising from climate change and
energy use is seen, but at the cost of increases
in eutrophication, and particularly acidification
resulting from increased NH
3
emissions follow-
ing the spreading of the slurry. Terrestrial eco-
toxicity is also increased significantly, due to
the presence of copper and zinc in the pig
slurry. Thus, while the use of pig slurry may be
of economic interest, generally speaking its
effect on the environmental performance of
hemp is a negative one.
By contrast, the use of no-till is interesting
for it reduces energy uses, acidification and cli-
mate change. These effects result from reduc-
tions in diesel use and in the use of agricultural
machinery. No-till also presents other environ-
mental advantages, including a reduced risk of
erosion and an increase in the organic material
levels in the soil.
Any measures allowing the washout of
nitrates to be reduced are likely to prove inter-
esting, because a 50% reduction in nitrate
washout has been shown to result in a 43%
reduction in eutrophication and a 10% reduc-
tion in climate change. Whereas the reduction
in eutrophication arises directly from reduced
nitrate emissions, the effect on climate change
is indirect and results from a lowering in N
2
O
emissions arising from the denitrification of
NO
3
. In general, optimizations in nitrogen fer-
tilization and reductions in the time between
harvesting and the planting of the next crop
are the main measures recommended to reduce
nitrate emissions.
the lowest environmental impact. This differ-
ence is particularly notable when comparisons
are made with potato and sugarbeet, which
can be described as crops with high-input
requirements and a higher impact.
The use of low-intensity tillage (no-till)
allows the environmental credentials of hemp
to be improved yet further. This study has there-
fore allowed us to quantify the environmental
impact of hemp, showing it to be relatively low
compared to the other crops in this study.
Acknowledgements
These studies were conducted with a contribu-
tion from the European Union as part of the
project QLK5-CT-2002-01363 'HEMP-SYS'.
The data and opinions presented here are
those of the author (Hayo van der Werf) and do
not represent the opinions of the EU. The
French corrections of Agnès van der Werf are
also acknowledged.
21.3 Conclusions from
the Life Cycle Analysis
21.3.1
Objectives of the study
The French hemp industry is seeking to diver-
sify into new markets. In addition to supplying
the paper industry, it is also targeting new mar-
kets in areas such as plastics/plasturgy (ther-
moplastic compounds containing hemp fibre)
and the building trade (walls made of hemp
cement on a wooden frame). Knowledge of the
potential environmental impact arising from
the production of these two products is required
in order to identify the environmental benefits
accruing as a result of the use of hemp in their
manufacture. These properties have not been
fully proven, despite the fact that a number of
studies have been undertaken.
In order to evaluate the potential environ-
mental impact of thermoplastics, plastics con-
taining hemp fibre, and of walls made with hemp
concrete, the FNPC and INTERCHANVRE
meet the ISO 14040 Standard for Life Cycle
21.2.5 Conclusions
This study assumed that crops were produced
in France according to good agricultural prac-
tice (BPA). In France, the BPA correspond very
much to those applied elsewhere in Western
Europe. For this reason, the results of this
study, while based on the situation in France,
are applicable to the situation found elsewhere
in Western Europe.
Relative to the other crops examined in
this study, hemp and sunflower are the crops
requiring the lowest amount of inputs and with
