Report from the Sub-comittee on the environment and health

Conclusion concerning
emissions of greenhouse
gases
Conclusions concerning
leaching of nutrients
The sub-committee’s
conclusions concerning
proportionality
226
arable farming in Denmark would not change significantly in <strong>the</strong> event of
restructuring for pesticide-free operation, but that this must be seen in
relation to a considerable fall in yield – about 25%. The sub-committee
has not considered <strong>the</strong> extent to which a changed production pattern, e.g.
reduced livestock production, would reduce energy consumption.
The agricultural sector’s domestic contribution to <strong>the</strong> greenhouse effect
is approx. 13 Tg CO2-equivalents. CO2 <strong>from</strong> fossil fuel consumption
accounts for around one quarter of this, and methane and nitrous oxide
for <strong>the</strong> remainder. If <strong>the</strong> yield was reduced by pesticide-free operation,
import of feedstuff would mean a higher overall energy consumption. It
has not been possible, on <strong>the</strong> existing basis, to assess changes in
emissions of methane gas and nitrous oxide in <strong>the</strong> different scenarios.
The sub-committee believes that changes in mechanical soil treatment
and changed crop rotations would affect <strong>the</strong> leaching of nutrients. The
changes could be both adverse and beneficial. An extensive analysis
would be needed to assess <strong>the</strong> net change, but would be encumbered with
great uncertainty. All else being equal, in <strong>the</strong> 0-pesticide scenario, <strong>the</strong>
reduction in yield would result in a smaller consumption of fertiliser and
thus reduced leaching. On <strong>the</strong> o<strong>the</strong>r hand, in <strong>the</strong> event of crop failure –
for example, as a result of fungal diseases – increased leaching could be
expected. Leaching would thus depend, <strong>from</strong> year to year, on an
interaction between <strong>the</strong> choice of crop, <strong>the</strong> level of fertilisation, <strong>the</strong>
intensity and timing of soil treatment, and plant health. The
implementation of Aquatic Environment Plan II would be accelerated in
step with <strong>the</strong> reduction of fertiliser consumption in <strong>the</strong> different
scenarios.
11.9 The sub-committee’s conclusions and recommendations
concerning proportionality
• The heavy metals cadmium, lead and mercury present a bigger health
problem than pesticides but are not a serious problem
environmentally. However, attention must be paid to a potential
accumulation in cultivated soil of, in particular, cadmium, lead and
copper.
• Compared with <strong>the</strong> effects of pesticides, <strong>the</strong> direct effect of xenobiotic
substances on cultivated soil and thus on crops is small. However,
little is known about potential, indirect pollution by xenobiotic
substances, for example via air or through accidental loss, spillage or
discharge to water. There may <strong>the</strong>refore be grounds for concern since
<strong>the</strong> long-term effects of even small concentrations are not known.
With <strong>the</strong> environment policy now pursued, efforts are being made,
both nationally and internationally, to ensure a reduction at source,
but owing to <strong>the</strong> continuing supply of such substances, <strong>the</strong> load must
be monitored on a long-term basis.
• Organic pollutants are not generally a problem in cultivated soil. With
frequent application of sludge on <strong>the</strong> same area, <strong>the</strong> total quantity of
xenobiotic substances can be of <strong>the</strong> same order of magnitude as <strong>the</strong>
pesticide load.