Conference Agenda

Agricultural residues, such as post-harvest barley straw and perilla stems, are by-products of routine farming activities. These residues are often illegally burned in open fields without air pollution control facilities, directly releasing short-lived climate pollutants (e.g., NOx, CO, and VOCs) and particulate matter (PM₁₀ and PM₂.₅) into the atmosphere, thereby contributing to air pollution and environmental and climatic risks.

This study developed an experimental system simulating real open-field burning conditions using domestic and international guidelines, including EPA Method 5G and EPA-600. Using this system, emission factors for SLCPs and particulate matter were developed for agricultural residue(perilla) burning. Estimated emission factors were PM₁₀ = 0.02205 kg/kg and PM₂.₅ = 0.02027 kg/kg, representing reductions of 13% and 5%, respectively. SLCP emission factors were estimated as NOx = 0.00206 kg/kg, CO = 0.05181 kg/kg, and VOC = 0.00865 kg/kg, corresponding to reductions of 87%, 86%, and 84%, respectively.

Applying the developed emission factors to national inventories substantially reduced estimated emissions, including PM₁₀ (−361 tons), PM₂.₅ (−120 tons), NOx (−1,477 tons), CO (−34,760 tons), and VOC (−4,853 tons). These results provide a scientific basis for improving emission inventories and supporting evidence-based air quality and climate policies.

Accurately measuring emissions of methane (eCH₄) and ammonia (eNH₃) from naturally ventilated dairy barns (NVDBs) remains technically and economically demanding due to highly variable airflow conditions. To explore affordable monitoring approaches, a long-term field campaign was initiated in December 2025 in a German NVDB housing 60 dairy cows. Two affordable greenhouse gas analyzers, LoGas-TDLAS and LoGas-NDIR, and an ammonia analyzer (LoGas-EC) were calibrated on-farm against a standard CRDS reference. Emissions were estimated using the CO₂ balance method. The indoor and outdoor air samples were distributed with respective external vacuum pumps simultaneously to all gas analyzers. Preliminary analysis of the first two weeks (6684 data-points) showed strong agreement between the affordable sensors and the CRDS reference (R² > 0.90). Compared with the CRDS-derived mean eCH₄ emission (6.68 g h⁻¹ LU⁻¹), LoGas-TDLAS and LoGas-NDIR estimated 5.97 and 7.04 g h⁻¹ LU⁻¹, corresponding to deviations of −10.5% and +5.3%, respectively. Mean eNH₃ emissions derived from LoGas-EC were 0.41 g h⁻¹ LU⁻¹, representing a −12.7% deviation relative to the CRDS (0.47 g h⁻¹ LU⁻¹). Results demonstrate that affordable analyzers can reliably capture temporal emission dynamics in NVDBs with acceptable uncertainty. At the conference, seasonal variability and long-term (campaign: 09.12.2025-01.06.2026) instrument performance will be presented.

A multi-stage measurement approach was used to investigate the effect of diets containing tannin-rich forage (sainfoin) and/or extract (Acacia mearnsii) on CH₄ and NH₃ emissions. First, six different diets combining three silages (ryegrass; sainfoin; red clover) and two concentrates (control; acacia extract) were studied at individual animal level. A N balance experiment with six cows was coupled with CH₄ and NH₃ release trials from slurry using a dynamic chamber. Enteric CH₄ from 30 cows was determined with Green Feeds. From these investigations at individual animal level two promising diets ‘sainfoin’ and ‘sainfoin+acacia’ were selected and compared with a grass silage diet on a practical scale. In a case-control approach, NH₃ and CH₄ emissions from two naturally ventilated compartments (each 20 cows) were quantified using a tracer-ratio method.

Feeding sainfoin lowered, slurry-based CH₄ release and enteric CH₄ production. Acacia reduced urinary urea N (29%) and NH₃ release from slurry (37%), and decreased enteric CH₄ production. Slurry-based CH₄ was reduced by acacia only in the ryegrass diet. In practical scale sainfoin and sainfoin+acacia diets reduced NH₃ emissions by 16-33% and 30-38%, respectively, with greater reductions at higher temperatures. CH₄ emissions were reduced with sainfoin (10%) and sainfoin+acacia (20%), less affected by temperature.

Methane emissions from liquid manure storage represent a significant source of agricultural greenhouse gases and are commonly quantified in national inventories using IPCC Tier 2 Methane Conversion Factors (MCF). These default values rely largely on literature data, climatic classifications, and expert judgement, representing temporally averaged emission conditions for typical storage systems. However, farm-specific management, substrate dynamics, and seasonal variability are only partially reflected. Therefore, this study aims to determine monthly and seasonally resolved MCFs for cattle liquid manure, comparing them with current default factors, and identifying approaches to improve representativeness.

Under farm-like, in vitro conditions, liquid manure storage was simulated, including continuous feeding, periodic removal, and realistic retention times. The maximum methane-producing potential (B₀) was determined monthly to derive temporally resolved MCFs. Initial results reveal pronounced seasonal variations associated with changes in substrate composition, microbial activity, and temperature, exceeding the assumptions of constant Tier 2 default values.

We therefore propose more process-based, temporally differentiated approaches to determine MCF, including monthly or seasonal factors, integrating farm management practices, and establishing regional datasets with explicit uncertainty assessment. The results demonstrate that temporally explicit MCF approaches can improve the accuracy of GHG inventories, support mitigation strategies, and optimize emission management in livestock systems.

Outdoor slurry storage tanks are a source of methane, which is a strong greenhouse gas. Acidification with sulfuric acid represents a strategy to mitigate emissions. The applied dose is critical in relation to cost and efficiency. A pilot-scale study demonstrated significant reduction at 2 kg m^-3 slurry. This study aimed to evaluate the impact of early acidification targeting this concentration in full-scale covered tanks.

Covered storage tanks are naturally ventilated, and quantification of methane emissions requires accurate determination of the air exchange rate. Nitrous oxide was injected as a tracer gas, and its concentration decay was used to estimate ventilation rates. Methane and nitrous oxide concentrations were determined at two locations within the tank’s headspace using a cavity ring down spectroscopy analyzer.

Results showed homogeneous tracer mix and no sign of interference by endogenous nitrous oxide generation. Acidified pig slurry tanks exhibited a 92% reduction in methane emissions and cattle tanks a 43% reduction compared with non-acidified tanks.

In conclusion, low dose acidification is a viable strategy in full-scale storage tanks, and the tracer decay method provides reliable air exchange rates estimates in cover tanks.

Liquid dairy manure storage is a major source of agricultural greenhouse gas emissions, yet emission dynamics under continuously filled conditions remain poorly quantified over annual timescales. In this study, a laboratory-scale system simulating farm liquid manure storage operated continuously for 15 months with daily feeding and periodic partial emptying, enabling long-term monitoring under realistic management. Gas emissions showed clear seasonal variability: daily emissions peaked at 4.5 L d⁻¹ in summer, declined sharply after emptying, and remained low through winter and spring. Methane concentrations rose to 60% during warm periods, whereas carbon dioxide dominated in colder seasons. Nitrous oxide remained negligible (<0.5 ppm) throughout. Methane fluxes followed seasonal patterns, peaking at 3.9 g kg⁻¹ FM d⁻¹ in summer, increasing transiently in autumn, and staying low in winter and spring. Methane contributed over 80% of total CO₂-equivalent emissions. These results demonstrate pronounced temporal variability driven by seasonal conditions and storage management, highlighting the importance of long-term monitoring to improve emission assessments under practical farm conditions.

This study evaluated the ammonia (NH₃) mitigation using ball-type floating covers in a nursery pig house slurry pit. NH₃ is a critical precursor of secondary PM_2.5 and a major contributor to odor emissions, yet effective on-site mitigation strategies remain limited. Over a 56-day period, a treatment group (410 pigs) used a slurry pit (188.5 m²) filled to 30% depth with aerated liquid fertilizer and covered with 21,000 floating balls (10cm diameter, 85.9% coverage), while control group (450 pigs) remained uncovered. NH₃ emissions were estimated weekly using ventilation rates and real-time gas concentrations measured at the exhaust. Average daily NH₃ emissions were 0.77±0.07g pig^-1 d^-1for the control and 0.12±0.01g pig^-1 d^-1 for the treatment, corresponding to an 84% reduction (p<0.05). These findings demonstrate that the combined use of ball-type floating covers and aerated liquid fertilizer significantly enhances NH₃ mitigation, offering a practical strategy for environmentally sustainable swine production.