Comparison of the Environmental Impact of Three Forms of Nitrogen Fertiliser

Keywords: Life Cycle Analysis, nitrogen fertilisers, ammonium nitrate, environmental performance.

The purpose of fertilisation is the optimisation of plant nutrition and the maintenance of the fertility of soils. Whilst they are essential to plant nutrition, fertilisers nevertheless make a substantial contribution to the environmental footprint of crop production. Accordingly, the optimisation of fertilisation performance is both a key issue and a lever for environmental improvement. While good nitrogen fertilisation is already well-known and familiar to farmers, environmental differentiation between the main forms of nitrogen fertiliser is a lever for improvement which has yet to be analysed.

GPN and InVivo AgroSolutions therefore decided to work on a comparative Life Cycle Analysis of the three main forms of fertiliser used in France, in order to obtain a reliable and objective comparison of their respective environmental impacts on large-scale crop cultivation. This analysis has been validated by a critical review, which was conducted by in-house experts from both companies and supervised by the BioIntelligence Service.

The conclusions of this analysis reflect the superior environmental performance of ammonium nitrate produced within the European Union, in comparison with urea or nitrogen solution of non-European origin, in terms of all calculated indicators. In the interests of clarity, only the three of these indicators (potential contribution to climate change, consumption of non-renewable primary energy, potential for acidification) have been considered for communication purposes, while the remaining indicators will provide a means of guarding against any transfers of pollution.

The superiority of ammonium nitrate can be explained by the following:

~ optimised industrial processes associated with stronger environmental pressures in Europe;

~ variable emissions of pollutant molecules in the field associated with different chemical composition;

~ differences in agronomic efficiency.

Sophie Marquis¹, Thierry Genter¹, Aurélie Buet², Amandine Berthoud².

¹ GPN, 16-40 rue Henri Regnault, 92902 Paris La Défense Cedex, France.

² InVivo AgroSolutions, 83 avenue de la Grande Armée, 75782 Paris Cedex 16, France.

24 pages, 6 figures, 6 tables, 14 references.