Trace Gas Emissions During Manure Spreading At Field and Lab Scale: Ammonia.

Livestock agriculture produces enormous amounts of manure in the U.S. every year. Air emissions from livestock manure contribute to air pollution problems ranging from the local to the global scale. It has been estimated that the contribution of livestock agriculture to total terrestrial emissions in the US are 50% of ammonia. Manure on applied fields generates massive amounts of ammonia.  Thus, transport of nitrogen species could lead to global warming and eutrophication. Also, nitrogen species emission from soil indicates loss of nutrients.

Ammonia emissions are being monitored following land application of dairy manure to determine the impacts of application technique and anaerobic digestion on emission of these pollutants. Our first goal is to develop data regarding the fate and transport of ammonia during land manure application using untreated or anaerobic digested manure. A second objective is to characterize captured nitrogen species during the volatilization process. Third, we will develop and validate emissions models for ammonia and nitrogen species following land application of manure or digester effluents using conventional broadcast, low-height broadcast, and injection application methods. To date, ammonia emission flux from manure-amended soils have been measured following conventional splash-plate spreading, direct injection, and drag-hose application of manure both in field and laboratory settings. As a preliminary result, conventional broadcast spreading produces the highest nitrogen emissions from both the field and lab soil experiments.