|Thompson, Rodney - POST-DOC, ARS|
|Jokela, W - UNIVERSITY OF VERMONT|
Submitted to: American Society of Agronomy
Publication Type: Abstract Only
Publication Acceptance Date: September 11, 2001
Publication Date: N/A
Technical Abstract: An estimated 40-50% of the ammonia (NH3) emitted from agriculture has been attributed to land application of manure or urea containing fertilizer. This is a direct loss of plant available nitrogen (N) and a possible N input to low-N ecosystems through atmospheric transport and deposition. The major factors influencing NH3 losses from land applications are: manure composition, fertilizer type, application method, and weather conditions. Ammonia volatilization from liquid manures can amount to 70% of the NH4-N within a day, compared to about 30% of the NH4-N from solid poultry manures over a week. Application method greatly affects losses with the largest losses occurring from unincorporated surface applications; an 80-90% reduction in volatilization can be realized by immediate soil incorporation. Weather conditions also impact NH3 losses with volatilization increasing with weather conditions that favor evaporation. Understanding and quantifying NH3 volatilization for a range of N sources, application methods, weather conditions, and soil types will provide a database for improved management techniques that will keep NH3 on the farm and out of neighboring ecosystems.