Author
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Harper, Lowry |
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Sharpe, Ronald |
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Submitted to: 1997 Southeast Sustainable Animal Waste Workshop
Publication Type: Proceedings Publication Acceptance Date: 8/15/1997 Publication Date: N/A Citation: N/A Interpretive Summary: Seventy-five percent of swine production systems in North America use anaerobic or liquid/slurry systems for waste holding or disposal. Accurate emissions and emission factors are needed for engineering, planning, and regulatory agencies for system design and for the evaluation of animal concentration effects on the regional soil, water, and atmospheric environment, Ammonia emissions were measured on a swine waste lagoon using techniques which minimize interference of transport processes by the measurement system. Ammonia emissions varied with windspeed, water temperature, lagoon water ammonium concentration, and lagoon water acidity. A statistical prediction equation was developed from the measurements which could predict emissions with a 60% probability using the above four independent variables. Of the nitrogen input into the lagoon system from the swine houses, about 25% was emitted to the atmosphere as gaseous ammonia, two percent irrigated to a forage, one percent was retained in the lagoon, and two-thirds was unaccounted for. Further studies are needed to measure emissions from animal housing losses characteristic to U.S. swine production, to assess the unaccounted N components, and to evaluate other trace gas emissions from the waste lagoons. Technical Abstract: Seventy-five percent of swine production systems in North America use anaerobic or liquid/slurry systems for waste holding or disposal. For system design and evaluation of the effect of animal concentrations on the regional soil, surface and ground waters, and atmospheric environments, accurate emissions and emission factors are needed for engineering, planning, and regulatory agencies. These studies have used non-invasive techniques to evaluate radiatively active and other trace gases without disturbing the meteorology or lagoon system being measured. Micrometeorological and gas sensors were mounted on a submersible barge in the center of the lagoon to determine trace gas fluxes over extended periods. Flux-gradient methodology was used for atmospheric flux measurement. Collateral measurements included lagoon nutrient and dissolved gas concentrations. Ammonia emissions varied diurnally and seasonally and were highly correlated with ammonium concentration and water temperature. Nutrient loading measurements showed that mobile ions, which were non-volatile, were constant throughout four successive lagoons. Immobile ions concentrated primarily in the sludge layer of the first lagoon. Nitrogen mass balance showed losses by gas emissions (25%, with 14% from the primary lagoon), retention (1%), seepage (5%), and irrigation onto crops (2%) with 67% unaccounted. |
