GPN and InVivo conducted an environmental assessment of the three major forms of nitrogen (ammonium nitrate 33.5, urea and UAN) over the entire life cycle (from production to use).

The results of this study are clearly in favor of the ammonium nitrate produced by 33.5 GPN: lower environmental impact and improved energy balance. This is due both to differences in production processes, with differences of gaseous emissions in the field and to a greater agronomic effectiveness of ammonium nitrate.

Thus, emissions of greenhouse gas emissions are almost 40% than with UAN with nitrogen. The primary energy consumption is 50% than with ammonium nitrate with urea.

More informations : http://www.ammo-hp.com/Analyse_de_cycle_de_vie.html