Are ammonia emissions from field-applied slurry substantially over-estimated in European emission inventories?

Abstract

<jats:p>Abstract. The EMEP/EEA guidebook 2009 for agricultural emission inventories reports an average ammonia (NH3) emission factor (EF) by volatilisation of 55% of the applied total ammoniacal nitrogen (TAN) content for cattle slurry, and 35% losses for pig slurry, irrespective of the type of surface or slurry characteristics such as dry matter content and pH. In this review article, we compiled over 350 measurements of EFs published between 1991 and 2011. The standard slurry application technique during the early years of this period, when a large number of measurements were made, was spreading by splash plate, and as a result reference EFs given in many European inventories are predominantly based on this technique. However, slurry application practices have evolved since then, while there has also been a shift in measurement techniques and investigated plot sizes. We therefore classified the available measurements according to the flux measurement technique or measurement plot size and year of measurement. Medium size plots (usually circles between 20 to 50 m radius) generally yielded the highest EFs. The most commonly used measurement setups at this scale were based on the Integrated Horizontal Flux method (IHF or the ZINST method (a simplified IHF method)). Several empirical models were published in the years 1993 to 2003 predicting NH3 EFs as a function of meteorology and slurry characteristics (Menzi et al., 1998; Søgaard et al., 2002). More recent measurements show substantially lower EFs which calls for new measurement series in order to validate the various measurement approaches against each other and to derive revised inputs for inclusion into emission inventories.</jats:p>

A parameterization of the heterogeneous hydrolysis of N&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;5&lt;/sub&gt; for mass-based aerosol models: improvement of particulate nitrate prediction

“…This is comparable with other models (Im et al, 2015). However, short periods with strong overestimations of [NO − 3 ] were also observed in previous New scheme (this study) 50 % * * Suggested by Sintermann et al (2012), Backes et al (2016), and Chen et al (2016b). studies. This seems to be the case for the HOPE Melpitz campaign simulation, during which COSMO-MUSCAT highly overpredicted [NO − 3 ] over Germany in this study (Fig.…”

“…Note that EC and BC are usually interchangeable in modelling studies (Vignati et al, 2010;Chen et al, 2016a;Nordmann et al, 2014). The emission of NH 3 was reduced by 50 %, since over 90 % of NH 3 emissions in Europe are contributed by agricultural sources (Hertel et al, 2011;Erisman et al, 2008;Reidy et al, 2008), and agriculture emissions of NH 3 are overestimated by ∼ 50 % or even more (Sintermann et al, 2012;Backes et al, 2016). Also, Chen et al (2016b) adopted the same NH 3 emission inventory in the WRF-Chem model and reported that total NH 3 was overestimated by a factory of ∼ 2 at Melpitz during the campaign period.…”

Advances in understanding, models and parameterizations of biosphere-atmosphere ammonia exchange

“…For field applied manures, the pH of cattle and pig slurries is typically in the range 7.5-8, but values down to 6.3 and up to 9.0 have been reported (Sintermann et al, 2012). This, combined with the natural variability of soil pH across agricultural landscapes in which manures are applied to land, contributes to the large variability in fluxes and NH 3 emission factors (EF) (Génermont and Cellier, 1997;Søgaard et al, 2002;Sommer et al, 2003;Sintermann et al, 2012).…”

“…This, combined with the natural variability of soil pH across agricultural landscapes in which manures are applied to land, contributes to the large variability in fluxes and NH 3 emission factors (EF) (Génermont and Cellier, 1997;Søgaard et al, 2002;Sommer et al, 2003;Sintermann et al, 2012). It should be noted that farmers typically monitor and manage soil pH to insure it is in an optimal range for the crop being produced and models should take this into account when estimating NH 3 fluxes for agricultural crops.…”

Ammonia emissions from a grazed field estimated by miniDOAS measurements and inverse dispersion modelling

“…Dynamic chambers or movable wind tunnels may be used to estimate emissions from simulated grazing in the laboratory or the field ). However enclosure measurements may not always be representative of emissions at the field scale (Genermont and Cellier, 1997;Sintermann et al, 2012). The inverse dispersion method concerns the inferring of the atmospheric emission rate (Q) of localised gas sources from the excess concentration ( C) they cause above background, by modelling the C/Q relationship for a given source-receptor configuration and meteorological state (Flesch et al, 2004(Flesch et al, , 2014.…”