MICROBIAL ACTIVITIES AND FEEDLOT EMISIONS

Authors: Miller, Daniel; Berry, Elaine; Varel, Vincent

Submitted to: Soil Science Society of America Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 8/11/2004
Publication Date: 11/4/2004
Citation: Miller, D.N., Berry, E.D., Varel, V.H. 2004. Microbial activities and feedlot emisions. Procedings of the International Annual Meetings of the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, October 31 - November 4, 2004, Seattle, WA, 2004 CDROM.

Interpretive Summary:

Technical Abstract: A lack of detailed information describing how microbial activities, influenced by the beef cattle feedlot surface environment, affect a variety of cattle feedlot emissions (greenhouse gases, ammonia, odor compounds, and particulates) limits our ability to predict and control emissions. Moisture and manure content are two critical factors selected for initial investigation, which are likely to affect the general metabolic state of microorganisms in the feedlot surface, and hence, emissions. A general conceptual model was developed relating manure and moisture content to microbial metabolic state at the feedlot surface and associated emission issues based upon the results of a series of laboratory incubations. Three microbial metabolic states (anaerobic, aerobic, and inactive) were identified that aligned well with potential emissions. The potential to emit depended upon the metabolic state of the microbial community, which in turn was influenced mostly by moisture content. The magnitude of a particular emission was more closely tied positively and, in some cases, negatively to increasing manure content. Based upon the general conceptual model developed in this series of studies, the optimum management of manure and moisture content in the feedlot surface may be within a narrower moisture regime and at lower manure content than current practices recommend.