Location: Livestock Nutrient Management ResearchTitle: Diurnal measurements of methane emissions from a feedyard pen surface in Texas during Spring Author
Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 8/21/2018
Publication Date: N/A
Technical Abstract: Methane, a potent greenhouse gas is produced under anaerobic conditions from the manure management systems at animal production facilities. At beef cattle feedlots, the primary manure management system source is the pen surface. In the April 2018 trial reported here, six automated Licor Long-Term chambers were set up on a grid within a recently vacated pen at a commercial Texas High Plains feedyard. Over a five-day period, the chambers were closed in sequence each hour with the headspace methane concentration being measured with a Los Gatos Enhanced Performance Greenhouse Gas Analyzer. The pen surface condition was dry and dusty with about 25 mm of dry friable material overlaying compacted manure of variable thickness. The average ambient temperate during the monitoring period was 12.1°C [Range: 28.0°C to -6.5°C]. Fluxes were monitored for 48 hours before 13.1 mm of water was added to each of the chamber bases to simulate a rainfall event. Flux monitoring continued for a further 48 hours while the emission response was observed. The measured fluxes showed temporal variation in response to diel temperature variation and significant spatial variation within the pen, with location partially indicating the reason for enhanced emissions. The average flux was 2.022 mg per square meter per hour [Range: 11.081 to -0.038] before the simulated rainfall event with one chamber exhibiting much higher emissions than any other chamber during that period. In the post rainfall event period, the average flux was 0.771 mg per square meter per hour [Range: 3.361 to -0.019]. Considerable ancillary data and physical samples have been collected as part of this trial. This data will be incorporated in this abstract as it becomes available from the physical, chemical and microbiological laboratories. Data from this trial will be used to inform emissions inventories and to enhance the process-based understanding of these emission processes.