LCA Food 2012 in Saint Malo, France! - Manifestations et colloques ...

GROUP 6, SESSION B: METHODS, TOOLS, DATABASES 8 th Int. Conference on LCA in the
Agri-Food Sector, 1-4 Oct 2012
162. A simple model to assess nitrate leaching from annual crops for
life cycle assessment at different spatial scales
Aurélie Tailleur * , Jean-Pierre Cohan, François Laurent, Afsaneh Lellahi
ARVALIS – Institut du végétal, Service Agronomie Economie Environnement, Boigneville, F-91720,
France, Corresponding author. E-mail: a.tailleur@arvalisinstitutduvegetal.fr
Life cycle assessment of food products show that nitrate leaching during crop production contributes significantly
to their eutrophication potential (Xue X, Landis AE, 2010). Different dynamic field-scale models enable
LCA-practitioners to estimate nitrate leaching taking into account detailed data about agricultural practices,
soil type and climatic conditions. In the meantime, their use at a higher spatial scale (production area,
region) requires collecting a high number of data on a representative sample of fields. In this study, we estimate
average potential nitrate emissions for twenty annual French crops, using an easy to perform method
based on the COMIFER (French Committee for the Development of Rational Fertilisation) methodology.
This methodology was previously established from experimental results to diagnose nitrate leaching risk at
different scales (watershed, small agricultural region, production area) and allows to classify the risk considering
agricultural practices (from a very low to a very high level in function of duration without N absorption,
absorption capacity of the following crops, slurry and droppings spreading in autumn, N input from
crop residues, Fig. 1) and some important site-specific related soil parameters (water retention capacity, volume
of drained water and soil organic matter content). The nitrate leaching amounts were attributed to each
risk level (Fig. 2), based on results from the experimental database of the institute. Statistical data from the
French Ministry of Agriculture about agricultural practices and our soil database were used to assess, at the
region scale, percentages of crop area corresponding to each risk level and then to estimate an average regional
nitrate leaching amount. Results will be compared with experimental results on particular sites and
model results on watershed scale provided by bibliography.
This work shows that we can easily use this methodology in the framework of LCA to provide potential nitrate
emission estimations at a regional scale. While these estimations may be less precise at smaller scale
than those from dynamic field-scale models as the comparison with experimental results could show it, it
requires collecting much less data and it takes into account the most impacting parameters to differentiate
contrasting situations.
Different emissions (N-gases, plant protection products) from crop production are very variable due to conditions
and practices. To estimate precisely these emissions, LCA-practitioners have often to face with an important
need for data. In the meantime, our work suggests that it is possible to establish structured and simplified
methods that can quickly and pertinently discriminate situations.
This work contributes to the Agri-BALYSE project which is aimed at providing a Life Cycle Inventory
(LCI) database for agricultural products. Average LCI representative of the French production will be supplied
for around twenty annual crops.
References
COMIFER, 2001. Lessivage des nitrates en systèmes de cultures annuelles. Diagnostic du risque et proposition
de gestion de l’interculture. COMIFER Ed. 41 p.
CORPEN, 1991. Interculture. CORPEN Ed. 40 p.
Cohan J.P., Laurent F., Champolivier L., Duval R., 2011. Diagnostic du risque de lixiviation du nitrate et
leviers d’actions. In « Cultures intermédiaires: enjeux et conduite ». Ed. ARVALIS-CETIOM-ITB-ITL ;
pp. 128-136.
Xue X, Landis AE, 2010. Eutrophication Potential of Food Consumption Patterns. Environmental Science
and Technology 2010, 44, 6450-6456.
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