METPART quantiAGREMI

Following on from a successful quantiAGREMI field campaign in Graswang, Germany in 2023 for WP3, a second campaign was conducted in Middenmeer, Netherlands from September to October 2024. quantiAGREMI project partners from both WP2 and WP3 (TNO¹, WUR², UKCEH³, TI⁴, VSL⁵, KIT⁶), alongside RIVM⁷, Healthy Photon Ltd., China and OnePlanet Research., Netherlands joined forces to evaluate methodologies in determining the ammonia (NH₃) emissions (WP2) and deposition footprint (WP3) around a livestock building.  

A network of passive UKCEH ALPHA® samplers was set up in the surrounding area to measure NH₃ concentrations, map the footprint around the building and compare in-situ performance with high resolution measurements. Following an open call, OnePlanet joined the campaign and co-located their NitroSense sensors within this network.

High temporal resolution NH₃ measurements were carried out using a suite of instruments (UKCEH, open-path analyser HT8700, Healthy Photon; TI, UKCEH, with and without passivation QCL systems, Aerodyne; RIVM, miniDOAS and LIDAR) located downwind of the livestock building to measure NH₃ concentrations and test the applicability of flux methodologies.

Remote sensing (mobile plume chase) measurements (TNO, HT8700) were taken to quantify emissions to compare to in-house methodologies - long term passive NH₃ concentration measurements taken inside the livestock building.

The Healthy Photon and Aerodyne QCL high resolution and plume chase instruments underwent NH₃ calibration testing using a system developed and tested for field application during the quantiAGREMI project.

During the study, soil samples were collected from various locations for determination of N isotopic composition in the laboratory. The information will be used to assess if N isotopic composition can be used as a proxy for the spatial extent of the near field N deposition footprint from a livestock building.

This study will provide essential data to improve understanding of the fate of NH₃ and to develop best practice guidelines for quantifying the NH₃ footprint around livestock buildings, as there is currently no standard guidance or approach.

High resolution equipment set-up. Photo: Karen Yeung

Passive samplers (OnePlanet NitroSense, UKCEH ALPHA®). Photo: Karen Yeung

¹Nederlandse Organisatie voor Toegepast Natuurwetenschappelijk Onderzoek, Netherlands ²Wageningen University and Research, Netherlands ³UK Centre for Ecology and Hydrology, United Kingdom ⁴Thünen Institute, Germany ⁵National Metrology Institute B.V., Netherlands ⁶Karlsruhe Institute of Technology, Germany ⁷ National Institute for Public Health and the Environment, Netherlands

Within WP3, soil samples from an ammonia release experiment have been collected. KIT have carried out extensive preparation of these samples prior to various analytical tests, including nitrogen isotope analysis. Soil preparation has included freeze-drying followed by milling/grinding to a fine powder.

For nitrogen isotope analysis by EA-IRMS, a few hundred microgrammes of nitrogen are required. This therefore required the painstaking task of precisely weighing out 5-6mg of each soil sample into small tin capsules. Scientists at KIT did this in duplicate for almost 50 soil samples. The prepared capsules containing soil were then shipped to LGC for analysis.

expanded uncertainties (0.023 to 0.031) on the slope of the regression line between the amount fractions of the generated gas mixtures and spectroscopic measurement results are consistent for all gas generators. However, while the generators agreed pairwise, overall agreement was absent. The sources of this discrepancy are now tracked down by the participating NMIs.

Average slopes of PTB spectroscopic measurement results and associated uncertainties determined for the NH₃ generators of METAS, VSL and LNE in dry air.

Average slopes of PTB spectroscopic measurement results and associated uncertainties determined for the NH₃ generators of METAS, VSL and LNE in wet air.

QuantiAGREMI project partners KIT, METAS, UKCEH and TI were joined by Bern University of Applied Sciences (Switzerland), EMORY University (USA), INRAE (France) to test and evaluate different measurement systems for the determination of ammonia (NH₃) fluxes. Since NH₃ has distinct adhesive properties and is extremely soluble in water, NH₃ flux measurements have remained a challenge. As such, quantification of the uncertainty of different NH₃ flux methods is pertinent to improve quantification of NH₃ emissions and deposition around livestock buildings. To address both emission and deposition fluxes a series of experiments was conducted during a field study in June/July 2023 in Germany. Background measurements were undertaken where it was assumed deposition fluxes would be the dominant feature. Subsequently, a known amount of NH₃ was released from a circular area within a small footprint of the field. Finally, a known amount of manure was applied to the entire agricultural site in order to cover the footprints of the different measurement approaches. This experiment will contribute to contextualize different measurement approaches as well as identify and characterize technologies for NH₃ flux measurements.

On November 24 2023, the Bavarian Farmers Association organized a symposium on ammonia emissions, manure acidification and manure amendments in the “House of bavarian agriculture” in Herrsching, Germany. QuantiAGREMI project partner KIT, together with Justus-Liebig University Giessen, was invited to give a keynote. Among other results from literature studies and laboratory incubation experiments, preliminary findings of the campaign to test and evaluate different ammonia flux measurement systems in June/July were presented.

On December 7 2023, QuantiAGREMI project partner KIT invited stakeholders to a workshop on “Relevance of manure, biogas residues, fertilizer additives and ammonia emissions for Nitrogen cycling in agricultural ecosystems” to the KIT Institute of Meteorology and Climate Research in Garmisch-Partenkirchen. The workshop was advertised through the German trade association of Biogas farmers. The fourteen participants, comprising farmers, consultants and researchers showed lively interest in the preliminary results of the campaign to test and evaluate different ammonia flux measurement systems in June/July 2023. The campaign was carried out by the QuantiAGREMI partners KIT, METAS, UKCEH and TI, who were joined by Bern University of Applied Sciences (Switzerland), EMORY University (USA), INRAE (France).