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ARS Home » Northeast Area » University Park, Pennsylvania » Pasture Systems & Watershed Management Research » Research » Publications at this Location » Publication #311874
Title: Volatile organic compound emissions from silage systems

Author
item Rotz, Clarence - Al
item HAFNER, SASHA - University Of Denmark
item MONTES, FELIPE - Pennsylvania State University
item MITLOEHNER, FRANK - University Of California

Submitted to: American Forage and Grassland Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 10/30/2015
Publication Date: 1/12/2015
Citation: Rotz, C.A., Hafner, S., Montes, F., Mitloehner, F. 2015. Volatile organic compound emissions from silage systems[Abstract]. American Forage and Grassland Conference Proceedings. p 1.

Interpretive Summary:

Technical Abstract: As a precursor to smog, emission of volatile organic compounds (VOCs) to the atmosphere is an environmental concern in some regions. The major source from farms is silage, with emissions coming from the silo face, mixing wagon, and feed bunk. The major compounds emitted are alcohols with other important compounds being organic acids, esters, and aldehydes. A model that predicts emissions of these four groups of VOCs was developed and incorporated in a farm simulation model (Integrated Farm System Model) where it is used to study management effects on silage emissions along with other farm emissions to air and water, production costs, and profitability. To illustrate the use of the model, a representative 100-cow dairy farm was simulated in central Pennsylvania. The total annual emission of ozone-forming VOCs was 1360 kg with 63% coming from corn silage, 20% from high-moisture corn and 17% from alfalfa silage. Most of the emission came from the silo face (78%) with the remainder occurring during feed mixing and from the feed bunk. The use of large tower silos in place of bunkers reduced the total emission by 1% with a 9% decrease in farm profit. Use of two smaller diameter silos in place of one larger tower silo reduced emissions 12%, but farm profitability was reduced an additional 8%. Use of silage bags reduced emission 22% while increasing farm profit 18%. Further work is underway to compare predicted emissions to those measured on dairy farms.