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| Titel |
Getting the Dimensions Right - Human Nutrition as Key for the Control of Regional Nitrogen Fluxes |
| VerfasserIn |
M. Zessner, S. Thaler, K. Ruzicka, S. Natho |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250030529
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| Zusammenfassung |
| The western society is rested upon a strong animal-based (meat, eggs, milk) nutrition, which
is far of a healthy balanced diet. Furthermore, the production of animal based food consumes
five to six times more resources (e.g.: area, fertilizer) compared to plant-based food and is
closely connected to environmental pollution (e.g.: emission of greenhouse gases, water
pollution). Especially the regional nitrogen turnover is highly driven by the request from
human nutrition on agricultural production. While the efficiency of the transfer of applied
nitrogen into the product is 60 – 70 % for vegetarian food, it is 15 – 25 % for animal based
food.
This contribution is going to demonstrate the most important nitrogen fluxes on national
scale in Austria calculated using a national material flow analysis. The national nitrogen
balance is driven by the production of nitrogen fertiliser and import of fooder. The airborne
transport of reactive nitrogen (NOX and NHX) plays a decisive role within this
balance. The main losses into the environment occur during the agricultural production
process. Losses to the atmosphere exceed losses to groundwater and surface waters.
After introduction of nitrogen removal at treatment plants, emissions to surface
waters are dominated by land use driven fluxes via groundwater. The influence of
nitrogen depositions on land (agricultural area, forest and mountain regions) on
nitrogen emissions to the water system is in the same order of magnitude as the
direct emissions due to fertiliser application – especially in a country as Austria
with high shares of mountainous and silvicultural areas. Sources for depositions of
reactive nitrogen are mainly NH3 emissions to the air from animal husbandry and
NOX emissions to the air from traffic. Both substance are matter of transboundary
transport and thus are highly influenced by activities outside a specific country or river
catchment.
Management of nitrogen on a national or catchment scale has therefore to consider
emissions to the air inside and outside the considered region (NH3 volatilisation from manure
and NOX-emissions from burning processes as traffic) in addition to the direct
losses to the water system (optimised fertiliser application). Basically, the key to
improved nutrient management on national/catchment scale is the human nutrition.
Nutrition of the population in accordance to health recommendations (50 % less
meet consumption, contra balanced by an increasing amount of vegetarian food)
would dramatically optimise the national nitrogen balance. Assuming the same
basic nitrogen efficiency of agricultural as it is performed at present, this shift in
production would lead to a dramatic relief in respect to environmental pressure. It
would lead to a reduction of the needed nitrogen input (mineral fertiliser and import
fooder) by about 40 % and a reduction of NH3 losses to the atmosphere of about
40Â % as well. Assuming that the same reduction of meet production would be
realised in neighbouring countries the deposition could be reduced by about 25 %.
Finally, this would lead to reduced losses of nitrogen to the water system by about
35Â %, which could be counter acted to some extent, if areas no longer needed for
food production are used for cultivation of crops for renewable energy production. |
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