Author
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Harper, Lowry |
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Sharpe, Ronald |
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Submitted to: Department of Environment and Natural Resources State of North Carolina
Publication Type: Other Publication Acceptance Date: 12/27/1998 Publication Date: N/A Citation: N/A Interpretive Summary: High animal concentration may provide increased production efficiency, improved production economics, and a better industry support system; however, it also presents a challenge to manage wastes to minimize ammonia losses which have potential short-and long-term effects on the surrounding environment. The purpose of these studies was to determine emissions appropriate for the regional climate, geography, and production systems. Ammonia emissions varied on a daily and seasonal basis and were related to lagoon ammonium concentration, acidity, temperature, and wind turbulence. A statistical model was developed from data of three lagoons in the Coastal Plains of North Carolina and Georgia. Comparison of emissions factors based on animal numbers from the two lagoons in North Carolina showed the danger of basing emissions strictly on animal numbers. A suggested emissions factor based on the USDA, Natural Resources Conservation Service, steady-state live animal weight showed similar emission factors for all lagoons measured in both states. Denitrification of ammonium to inert nitrogen gas was measured in all lagoons and showed significant quantities of nitrogen leaving the lagoons in this form. Technical Abstract: High animal concentration may provide increased production efficiency, improved production economics, and a better industry support system; however, it also presents a challenge to manage wastes to minimize ammonia losses which have potential short-and long-term effects on the surrounding environment. The purpose of these studies was to determine accurate emission factors appropriate for the regional climate, geography, and production systems. Micrometeorological instrumentation and gas sensors were placed over two lagoons to obtain information for determining ammonia emissions over extended periods and without interfering with the surrounding climate. Ammonia emissions varied diurnally and seasonally and were related to lagoon ammonium concentration, acidity, temperature, and wind turbulence. A statistical model was developed from data from three lagoons in the Coastal Plains of North Carolina and Georgia. The model explained 78% of the variability in emissions. Emission factors on two lagoons in North Carolina were compared based on animal numbers and showed that a highly concentrated lagoon, although three times concentrated, serving three times as many animals, and having twice the total emissions, had a per-animal lagoon emission factor of 60% that of a lesser concentrated lagoon. These comparisons exemplify the danger of basing emissions on animal numbers. A suggested emissions factor based the steady-state live animal weight showed similar emission factors for all lagoons measured in both states. Denitrification of ammonium to nitrogen gas was measured in all lagoons with higher rates of denitrification in more concentrated lagoons than in lower-concentration lagoons. |
