Johanna Pedersen

• Doctor of Engineering
• Aarhus University

Animal manure in livestock production facilities is a major source of methane (CH4) and ammonia (NH3) emissions from agriculture. In this study, we investigated different polyphenol-rich extracts and chemicals including commercial chestnut tannin (CT), shea meal extract (SME) and lignosulfonic acid (LSA) in combination with 1 mM of urease inhibitor...

Different technologies can be utilised to mitigate environmentally harmful ammonia (NH 3) emissions after field application of liquid animal manure (slurry). After a solid-liquid separation, air-plasma technology can acidify the liquid fraction and enrich its nutrient value by increasing the amount of inorganic nitrogen. The present work investigat...

Ammonia volatilization from animal slurry applied to agricultural fields reduces nitrogen use efficiency in agriculture and pollutes the environment. This work presents new versions of a model and database focused on this route of N loss. The public ALFAM2 database (https://github.com/AU-BCE-EE/ALFAM2-data) was expanded with ammonia emission and an...

Field-applied liquid animal manure (slurry) is a significant source of ammonia (NH3) emission, which is harmful to the environment and human health. To evaluate mitigation options, reliable emission measurement methods are needed. A new system of dynamic flux chambers (DFCs) with high-temporal-resolution online measurements was developed. The syste...

Ammonia emission following field application of animal slurry is a significant problem for the environment and human health. Accurate emission measurements are crucial for inventories, research, and mitigation. However, there may be large differences between results obtained with different methods. In this study measurement methods were compared in...

Field applied liquid animal manure (slurry) is a significant source of ammonia (NH3) emission, which is harmful to the environment and human health. To evaluate mitigation options, reliable measurements of effects are needed. A new system of dynamic flux chambers (DFC) with high time resolution online measurements was developed. The system was inve...

Volatilization of ammonia from field-applied animal slurry is a significant problem. Accurate emission measurements are needed for inventories and research, but are not provided by all measurement methods. Wind tunnels may give emission values substantially above or below micrometeorological results, which have been shown to be accurate. This limit...

Emission of greenhouse gases from liquid animal manure (slurry) can be reduced if slurry is treated through anaerobic digestion. The effluent from the reactor (digestate) can be utilized as a nutrient source for crop production if applied in the field. Physical and chemical properties of digestate vary considerably due to large variation in digeste...

Ammonia volatilization from animal slurry applied to fields is a major source of emissions throughout the world. The ALFAM2 model (Hafner et al., 2019) was developed for estimating ammonia emission from this source, and is used for research (Pedersen et al., 2022) and inventories (Hafner et al., 2021). In this contribution we will present recent de...

Poster presented at the RAMIRAN 2023 conference in Cambridge, UK.

Agricultural nitrogen (N) application to soils is the main source of atmospheric ammonia (NH3). Ammonia negatively impacts the environment on a large scale. However, emissions of NH3 are affected by spatiotemporal heterogeneities of soil parameters on a microscale. Some key parameters controlling processes of the N cycle are soil oxygen (O2) and pH...

Poster presented at the EGU 2023 conference in Vienna, Austria.

High ammonia (NH3) and odor emission can occur after land application of liquid animal manure. This study was aimed at evaluating NH3 loss and odor nuisance after field application of cattle manure and how it is affected by two anaerobic digestion strategies: i) digestion of cattle manure alone and ii) digestion with catch crops and dilution by wat...

Animal slurry contains plant nutrients such as nitrogen (N) that are essential for crop production. Inorganic slurry N is easily volatilised as ammonia after field application, reducing slurry fertiliser value and causing environmental problems. Ammonia emissions can be reduced by lowering slurry pH, rapid infiltration or incorporation of slurry in...

Field application of digestate from liquid animal manure (slurry) poses an environmental risk due to emission of ammonia (NH3). Various application techniques can reduce NH3 losses. Three experiments were conducted in Denmark where NH3 emission after field application of anaerobically digested separated cattle slurry was measured using dynamic flux...

To assess solid-liquid separation as a technology to reduce ammonia (NH3) emission from storage and field application of animal slurry, it is necessary to consider a possible higher NH3 loss from the solid fraction after application than from raw slurry, as well as losses during storage. A literature review was conducted, and a case study was devel...

Ammonia (NH3) emissions resulting from the field application of livestock slurry has both negative human health and environmental impacts. However, decreasing the exposed surface area (ESA) of slurry upon application can reduce NH3 volatilization by limiting its atmospheric exposure. In the present study, three strategies for depositing slurry with...

Agricultural nitrogen (N) application to soils is the main source of atmospheric ammonia (NH3) emissions. Ammonia negatively impacts the environment on a large scale. These emissions are affected by spatiotemporal heterogeneities of parameters within the soil on a microscale. Some key parameters controlling processes of the N cycle are soil oxygen...

Land spreading of liquid animal manure (slurry) is a major source of atmospheric emissions. Ammonia (NH3) emission is of concern, as it is one of the main contributors to ambient air pollution and nitrogen deposition. Storage and field acidification of the slurry prior to application is used to mitigate NH3 emission, but the effect of acidification...

To assess solid-liquid separation as a technology to reduce ammonia (NH3) emission from storage and field application of animal slurry, it is necessary to consider a possible higher NH3 loss from the solid fraction after application than from raw slurry, as well as losses during storage. A literature review was conducted, and a case study was devel...

"There's Something About Ammonia" is a comic featuring the well-intentioned cloud of ammonia who wants to be better. This work aims to increase awareness of ammonia pollution from farming to children from the age of eight upwards. It highlights impacts, sources, and solutions to the problem. The comic is available to download free from the UCD Rese...

Land spreading of liquid animal manure (slurry) is a major source of atmospheric emissions. Ammonia (NH3) emission is of concern, as it is one of the main contributors to ambient air pollution and nitrogen deposition. Storage and field acidification of the slurry prior to application is used to mitigate NH3 emission, but the effect of acidification...

Low-emission application technologies Sub-surface deposition slurry application Wind tunnels Ammonia (NH 3) loss during field application of liquid manure (slurry) causes loss of nutrients for the crops and contributes to contamination of the environment. The emission can be mitigated by different low-emission application technologies and slurry tr...

Field application of liquid animal manure (slurry) is a significant source of ammonia emission (NH3) to the atmosphere. It is well supported by theory and previous studies that air temperature effects NH3 flux from field applied slurry. The objectives of this study was to statistically model the response of temperature at the time of application on...

Ammonia (NH3) emissions from land-applied liquid manure (slurry) contribute to nitrogen deposition, acidification, and formation of fine particles in the atmosphere. Optimal management and field application techniques can reduce emission. A reduction in contact area between the slurry and the atmosphere is expected to reduce NH3 emission. The objec...

Field application of animal manure is a source of volatile organic compounds (VOC) and hydrogen sulfide (H2S) emission that contribute to air pollution and odor nuisance in local surroundings. In this study the non-methane volatile organic compounds (NMVOC) and H2S emission and odor activity dynamics over time after field application of pig and cat...

Field application of liquid manure contributes substantially to atmospheric ammonia. Low emission application methods are commonly used to reduce ammonia transfer to the atmosphere. To document which application method results in lower ammonia volatilization there is a need for high precision measurements to ensure that small differences in total e...

Soil surface measurements play an important role in the performance assessment of tillage operations and are relevant in both academic and industrial settings. Manual soil surface measurements are time-consuming and laborious, which often limits the amount of data collected. An experiment was conducted to compare two approaches for measuring and an...

Avoiding leaks is essential for accurate measurement of biogas production by batch assays. Here we present a simple method for detecting leaks and correcting results, based on the change in bottle mass during incubation. Three experiments were carried out using pure chemicals, wastewater sludge, and other complex substrates to test and demonstrate...

Avoiding leaks is essential for accurate measurement of biogas production by batch assays. Here we present a simple method for detecting leaks and correcting results, based on the change in bottle mass during incubation. Three experiments were carried out using pure chemicals, wastewater sludge, and other complex substrates to test and demonstrate...

Combining aerobic and anaerobic digestion in a two-stage system can improve the degradation of wastewater sludge over the use of either technology alone. But use of aerobic digestion as a pre-treatment before anaerobic digestion generally reduces methane production due to loss of substrate through oxidation. An inter-stage configuration may avoid t...

A summary of the biogas package and web app OBA