Agron. Sustain. Dev. 25 (2005) 101-107
DOI: 10.1051/agro:2004060

A laboratory system to estimate ammonia volatilization

Edith Le Cadre, Sophie Génermont, Céline Decuq, Sylvie Recous and Pierre Cellier

Institut National de la Recherche Agronomique, Unité Environnement et Grandes Cultures, BP 01, 78 850 Thiverval-Grignon, France

(Received 11 March 2004; accepted 8 October 2004)

Abstract - In addition to its environmental implications, ammonia volatilization is the principal source of variation of fertilizer efficiency. In a larger study estimating the effect of the dissolution step of fertilizer pellets on ammonia volatilization, we analyzed the sources of uncertainties in measuring low ammonia fluxes. The air humidity, and above all the air flow rate, are important contributors to the variation in fluxes. An exponential curve obtained from a set of 35 data points is proposed to normalize the ammonia emission rates according to the air flow rate (R² = 0.52). Modifications of the standard laboratory method are also proposed to improve the estimation of the low ammonia fluxes over a short timescale. However, the system was kept simple to manage, and reproducible to perform a statistical analysis of the results.

Key words: laboratory method / ammonia fluxes / uncertainties / pellet / synthetic fertilizer

Corresponding author: Sophie Génermont Sophie.Genermont@grignon.inra.fr

© INRA, EDP Sciences 2005