Greenhouse gas emission from liquid livestock manure storage is a considerable contributor to global warming and accurate farm-scale models for predicting emission are needed for estimating effects of manure management strategies. In this study we measured degradation of organic matter components of pig slurry with anaerobic and aerobic manure surface and at 10℃ and 20℃. Simultaneously, methane and carbon dioxide emission were measured and carbon emission from both anaerobic and aerobic processes was determined. Carbon dioxide loss due to surface respiration, did not limit methane emission during the incubation experiment at 10℃ and 20℃, but limited production of methane during subsequent anaerobic digestion at 38℃. Surface respiration rates varied between 10 - 80 g CO₂ m^-2 day^-1 and temperature dependent rate equations describing surface respiration was implemented in a farm-scale methane emission model (ABM). ABM simulations suggested that ca. 10% of carbon loss from typical slaughter pig barns and < 2% from outdoor pig manure storage was as carbon dioxide from surface respiration. Simulations also indicated that slurry filling level and seasonal variation in temperature considerably influenced methane to carbon dioxide emission ratio. This combined experimental and modelling study suggest that farm-scale models must reflect carbon loss from both aerobic and anaerobic process to accurately capture carbon emission dynamics and the farm-scale greenhouse gas emission.

How to cite: Dalby, F., Hafner, S. D., Feilberg, A., Ambrose, H. W., and Adamsen, A. P.: Modelling and measuring aerobic and anaerobic carbon loss from pig slurry storage, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-22103, https://doi.org/10.5194/egusphere-egu24-22103, 2024.

Methane (CH₄) emissions from outdoor manure storage tanks, from cattle and pig production, are complex and difficult to predict, therefore, the development of methods to monitor these emissions is needed. The mobile tracer gas dispersion method (TDM) has been used to quantify CH₄ emissions from entire facilities and can be used to discriminate emissions from different operations within a farm, although challenged by road limitations. To increase the use and flexibility of the TDM in quantification of CH₄ manure tank emissions, an alternative is to instead of measure concentrations using a mobile platform, the CH₄ and tracer gas concentrations can be sampled by using stationary sampling points. In this method (stationary TDM), a few parameters need to be examined to decrease the error in the emission quantification, for example, by considering the position of the sampling points within in the measured concentration plume. In comparison, by following methods’ best practices, the stationary TDM produced results like the mobile TDM, with relative errors of approximately 5 and 7%, respectively (Vechi & Scheutz, 2023). 

The mobile and stationary TDM methods were further used to quantify CH₄ emissions from outdoor manure tanks at pig and cattle farms and identify the factors affecting these emissions. Quantifications (6 to 14 measurements per tank) were done over several months, covering the entire year. In total, eight tanks were investigated, two of them stored cattle manure and six stored pig manure. The manure tanks measured emissions varied from 0.01 to 14.3 kg h⁻¹, which when normalized by the amount of manure stored corresponded to a range of 0.01 to 11.0 g m⁻³ h⁻¹. In a yearly average, cattle farm manure tanks emitted 0.63 ± 0.09 g m⁻³ h⁻¹, while pig emissions were higher, averaging 1.56 ± 0.93 g m⁻³ h⁻¹ (Vechi et al., 2023). Seasonal variation patterns were clear and similar among the different tanks, with emissions peaking between July to September and lower during winter and spring. The manure temperature was a significant factor correlated to the CH₄ emission fluctuations, followed by type of manure stored (cattle or pig) and tank cover (covered and uncovered). When comparing the amount of CH₄ emissions from the outdoor storage tanks to emissions from the entire farm, emissions from cattle manure tanks corresponded to 14 % of the total farm emissions, whilst, in pig farms, outdoor manure tanks covered from 21 to 64 % of the total emissions. There was a large variability in CH₄ emissions among pig manure storage tanks, likely caused by different management practices. To support further investigation, other factors such as microbial and chemical composition, combined with emissions quantification by TDM, which showed to be a simple and reliable method for CH₄ emissions measurements from manure storage tanks.

References:

Vechi, N. T., & Scheutz, C. (2023). Measurements of methane emissions from manure tanks, using a stationary tracer gas dispersion method. Biosystems Engineering.

Vechi, N. T., et al. (2023). Methane emission rates averaged over a year from ten farm-scale manure storage tanks. Science of the Total Environment.

How to cite: Thygesen Vechi, N. and Scheutz, C.: Quantification of methane emissions from outdoor manure storage tanks using the tracer dispersion method., EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-12673, https://doi.org/10.5194/egusphere-egu24-12673, 2024.

Particulate matter (PM) originating from agricultural practices poses a significant concern due to its potential adverse effects on the environment and human health. PM is typically categorized into two primary classes based on the particle size: PM10 (with an aerodynamic diameter of ≤ 10 µm) and PM2.5 (with an aerodynamic diameter of ≤ 2.5 µm).

The concentration of PM in the atmosphere is a crucial parameter determining air quality in both urban and rural areas. Numerous studies have demonstrated that short-term PM exposure is harmful to the respiratory and cardiovascular systems, highlighting a relationship between air particle pollution and hospital admissions due to respiratory and cardiovascular diseases.

In Italy, PM concentration is monitored daily, and public administrations have set a specific atmospheric concentration threshold equal to 40 µg m^-3 and 25 µg m^-3 for PM10 and PM 2.5 respectively.

PM pollution is also highly present in rural and agricultural areas. Estimates suggest that agricultural activities contribute approximately 17% and 3% to global PM10 and PM2.5 emissions, respectively. Primary PM emissions from agricultural activity arise from animal husbandry and open-field crop operations, including land preparation, field fertilization, and crop management.

In this context it is of crucial importance to understand and quantify PM emissions from agricultural activity, directing efforts towards the choice of a proper micrometeorological model to assess reliable emission rates.

This study aimed to measure PM10 emissions from three different field fertilization strategies: liquid slurry injection and two types of synthetic fertilizer spreading (potassium chloride - KCl and superphosphate - P₂O₅). The experiment was carried out on a farm located in Carmagnola (Province of Turin, Northern Italy) in a maize-cultivated soil. The selected field was divided into two main plots, which differed in the soil tillage technique, having one ploughed and one strip-tilled plot. The main plots were divided into three sub-plots, corresponding to the different fertilization strategies.

PM10 concentration was measured during each tractor passage using a PM monitor (TSI, DustTrack^TM II model 8530), and emission factors (EFs) were assessed with the backward Lagrangian stochastic model, by using a 2D sonic anemometer to monitor the wind field.

Experimental results revealed significant variations in PM10 emission among the different field fertilization strategies. The average EFs were significantly (P<0.05) higher for liquid slurry injection (72.63 mg m^-2) compared to KCl (0.43 mg m^-2) and P₂O₅ (2.6 mg m^-2) spreading.

How to cite: Dela Pierre, F., Rollé, L., and Dinuccio, E.: Assessment of PM10 emissions from agricultural field fertilization, comparison between mineral fertilizer and animal slurry spreading operations., EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-9517, https://doi.org/10.5194/egusphere-egu24-9517, 2024.

To address the growing demand for environmental and animal-friendly housing with outdoor space, there is a need for reliable techniques to quantify gaseous emissions. However, there is limited research on measurement methods to determine gaseous emissions from these housing systems. Therefore, this study focuses on developing measurement techniques to assess gaseous emissions from a novel concept of a welfare-friendly pig housing system with an outdoor run in the Netherlands. This concept employs measures like an optimal pen design and a daily excreta removal system where urine and faeces are directly separated. Within this concept new-born piglets stay in the same pen until slaughter weight is reached, promoting better excretion behaviour. The outdoor yard is designed with both slatted and solid flooring, aiding pigs in distinguishing between excretion and lying areas. This design feature is intended to contribute to the reduction of emissions and enhance animal welfare.

In the current study, to measure emissions and assess the potential for emission reduction, diverse techniques are outlined. Measurements are conducted at both barn and pen levels, employing the micro-meteorological technique coupled with inverse dispersion modeling, and N (and P/K) balance methods at the barn level. The micro-meteorological method measures gas concentrations upwind and downwind as well as the wind parameters, utilizing a modelling approach, i.e. the backward Lagrangian stochastic model, emission rates are computed. The N (and P/K) balance method estimates nitrogen emissions by measuring inputs, animal discharge, and nitrogen content in feces and urine during a balance period. At the pen level, local measurements are conducted to identify sources of ammonia emissions and quantify the emissions from the surface source by using an enclosure method, the fast box measurement system. The urine composition of all pig categories is assessed for NH4-N and urea-N content, as well as pH, through the collection of fresh urine. Urease activity on the solid floor inside and outside the pig house is determined using standard methods. Ammonia emissions from the urine-contaminated solid floor and solid floor with straw are measured at various temperatures and air velocities in the measurement box. Additionally, the urine-soiled area of the inside and outside solid floor, along with the frequency of urine discharges in different locations of the pen is determined using (heat) cameras. This information is then utilized to calculate ammonia emissions through an existing model.

The study comprises two phases: development and optimization, followed by implementation. Overall, this research aims to formulate a protocol for emission measurements and determination of the emission factors, contributing to a more comprehensive understanding of emissions from pig housing systems with an outdoor run, and promoting more sustainable and eco-friendly housing systems.

How to cite: Sefeedpari, P., Xie, F., and Aarnink, A. J. A.: Determining Gaseous Emissions from a Novel Pig Housing System with Outdoor Space: Comparison of Different Measurement Approaches, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-15496, https://doi.org/10.5194/egusphere-egu24-15496, 2024.

Ammonia is a hazardous air pollutant with detrimental impacts on both health and the environment. The primary sources of NH₃ emissions into the atmosphere are associated with agricultural activities and processes, including fertilizer utilization, decomposition of organic matter, and animal excretions. The characterization and quantification of NH₃ emissions in livestock environments are pivotal to comply with regulations and in assessing mitigation options. However, accurate monitoring of NH₃ emissions can be challenging due to the high reactivity of NH₃ and its tendency to adsorb to surfaces.

Here we present performance data for two new Cavity Ring-Down Spectroscopy (CRDS) ammonia analyzers that allow to accurately determine ammonia concentrations over a wide dynamic range: The SI2103 analyzer is the successor of the G2103 analyzer and the ideal solution for air quality monitoring at ambient concentrations as well as close to ammonia sources, and the newly released G2509 analyzer is the ideal solution to monitor ammonia concentrations along with CO₂, CH₄ and N₂O.

Key features of the SI2103 and the G2509 are: (i) excellent response time, (ii) low calibration requirements, (iii) field deployable, (iv) negligible interference (‘interference-free’) [1] , (v) long term unattended operation, and (vi) the possibility to measure multiple species. We will compare the performance of the SI2103 and the G2509 and discuss best practices for accurately measuring ammonia concentrations.

[1] Kamp, J. N., Chowdhury, A., Adamsen, A. P. S. & Feilberg, A. Negligible influence of livestock contaminants and sampling system on ammonia measurements with cavity ring-down spectroscopy. Atmos. Meas. Tech. Discuss. 1–20 (2019). doi:10.5194/amt-2018-377

How to cite: Hofmann, M. E. G., Woźniak, J., Swinkels, P., He, S., and Drori, K.: Continuous monitoring of ammonia (NH3) concentrations with Cavity Ring-Down Spectroscopy, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-15965, https://doi.org/10.5194/egusphere-egu24-15965, 2024.

Gaseous emissions from slurry storage tanks represent significant environmental and climate challenges. Accurate measurements of these emissions are essential for understanding their impact and developing effective mitigation strategies. However, measuring emissions of methane, ammonia, and nitrous oxide from full-scale slurry storage tanks can be challenging and it is practically impossible to obtain replicate measurement of the same slurry or test treatments under identical conditions.

To overcome this challenge, Computational Fluid Dynamics (CFD) modeling was used to investigate suitable dimensions for small-scale tanks. A tank diameter of 2.4 m and a height of 1 m was found suitable for emission measurements. As a method for measuring the emissions the Micrometeorological Mass Balance (MMB) method, where concentration and wind speed is measured at multiple heights above the tank, is a promising candidate as it has been proven to work on full-scale tanks for methane (Kariyapperuma et al., 2018; Park et al., 2010).

The plan was to validate the use of MMB on the small-scale tank while measuring in parallel with the backward Lagrangian Stochastic (bLS) method that have previously been used on full-scale slurry tanks (Lemes et al., 2022). Concurrent measurements with MMB and bLS were not useful as the concentration differences used for bLS were too small to estimate emissions. The measurement on pig slurry showed MMB emissions for methane and ammonia comparable to baseline emission in a recent review (Kupper et al., 2021), but the concentration response for ammonia indicated that it is questionable using a closed path instrument to measure ammonia emissions with MMB. In another validation experiment with IDM and MMB a known quantity of gas was released from a grid with 24 critical orifices inside the small-scale tank. In this case, bLS had a good recovery whereas MMB did not. The discrepancy was likely caused by the gas being released from discrete points and not uniformly from the entire surface. In a third validation experiment, MMB was compared to the Tracer Gas Method (TGM), where a known quantity of gas was released at three positions just below the slurry surface. The TGM and MMB emissions from methane agreed well in some intervals, but differed greatly in others, highlighting the challenges of measuring emissions from a small tank.

The observed issues emphasize the complexity of validating emissions from small-scale slurry tanks. Downscaling the tank also downscales emissions, which can be an issue using some methods and thereby making it difficult to do cross validation with different methods in parallel.

Downscaling provides opportunities to investigate natural variations and emissions of different slurry types under the same weather conditions in replicates, but the choice of an appropriate micrometeorological method is a complex challenge. 

References:
Kariyapperuma et al.: Agric. For. Meteorol., 258, 56–65, doi:10.1016/j.agrformet.2017.12.185, 2018.
Kupper et al.: Biosyst. Eng., 204, 36–49, doi:10.1016/j.biosystemseng.2021.01.001, 2021.
Lemes et al.: ACS Agric. Sci. Technol., 2(6), 1196–1205, doi:10.1021/acsagscitech.2c00172, 2022.
Park et al.: Agric. For. Meteorol., 150(2), 175–181, doi:10.1016/j.agrformet.2009.09.013, 2010.

How to cite: Kamp, J. N. and Feilberg, A.: Absolute emissions from slurry storage tanks with micrometeorological methods: Challenges of downscaling and method validation, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-17263, https://doi.org/10.5194/egusphere-egu24-17263, 2024.

This study was carried out to investigate the impact of fucosidase as a feed additive on mitigation of methane emission from fresh pig slurry in reactors mimicking housing and storage conditions. The study contained three treatment groups where fucosidase was added to the pig diets, 1) for two weeks after weaning, 2) for seven weeks after weaning, and 3) from weaning until slaughter. The treatments were compared to a control group without fucosidase. Fresh urine and feces were collected from three pigs in each treatment group at a bodyweight of ca. 30, 70, and 100 kg. Fresh feces and urine were added every second day to the housing reactors and after four weeks the slurry was moved to the storage reactors and kept at 15°C for twelve weeks. Cavity ring-down spectroscopy (CRDS) was used to measure methane concentration in the headspace air of the reactors. The results showed that there was no clear effect of the treatments at 30 and 70 kg. However, at 100 kg there was a significantly lower emission from the treated groups compared to the control. In the storage reactors there was no significant effect of the treatments. In conclusion, fucosidase as a feed additive can influence the methane emission from slurry under in-vitro conditions, but more research is needed to investigate the effect of dosage and if the same results can be obtained under real housing conditions.

How to cite: Heidarzadeh Vazifehkhoran, A. and Hansen, M. J.: Fucosidase as a feed additive to influence methane emission from pig slurry, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-21998, https://doi.org/10.5194/egusphere-egu24-21998, 2024.