Submitted to: Journal of Environmental Quality
Publication Type: Peer reviewed journal
Publication Acceptance Date: 1/29/2012
Publication Date: 5/1/2012
Citation: Dell, C.J., Kleinman, P.J., Schmidt, J.P., Beegle, D.B., Johnson, K. 2012. Low disturbance manure incorporation effects on ammonia and nitrate losses. Journal of Environmental Quality. 41:928-937. Interpretive Summary: Ammonia emissions following land application of livestock manures represent both a loss of plant-available nitrogen and an air quality concern. Incorporation of manure into soil with tillage can greatly reduce emissions, but is not compatible with no-till crop production. Three alternative manure incorporation methods were tested and ammonia emissions were compared to those following surface manure applications (with and without incorporation by tillage). Overall, a shallow disk injector provided greatest reduction in ammonia emissions with the least disruption of the soil surface. This research demonstrates that manure incorporation technology can be utilized on northeastern US dairy farms which reduces ammonia emission while conserving soil.
Technical Abstract: Ammonia volatilization represents a major mechanism of nitrogen (N) loss from land-applied manure and is an air quality concern. A field study was conducted to assess ammonia emissions related to manure application method in central Pennsylvania on a Hagerstown soil (Fine, mixed semiactive, mesic Typic Hapludalf) under continuous no-till. Dairy (Bos taurus) manure was applied in May 2006 and 2007 at a rate of 56,000 L per ha (67 to 84 kg ammonium-N per ha). Six treatments were evaluated: injection by shallow disk or high pressure; banding with soil aeration; broadcasting (with or without incorporation by chisel plow); and, no manure (control). Emissions were monitored for 72 h following application using ventilated chambers and passive diffusion samplers, with an average of 64 kg ammonia-N per ha volatilized from broadcast manure and negligible emissions (less than 1 kg ammonia-N per ha) from the control. Incorporation of broadcast manure by tillage within 1-h of application lowered ammonia-N emissions by 84% relative to broadcast, but delaying tillage will rapidly eliminate this benefit. Both the shallow disk and high pressure injectors lowered ammonia-N emissions by greater than 50% relative to broadcasting. Banding manure with soil aeration produced inconsistent results. It lowered ammonia-N emissions by 71%, relative to broadcasting, in 2007, but did not significantly affect emissions in 2006. Results confirm a significant reduction in ammonia emissions with both new and traditional methods of manure incorporation, but also point to broad variability between methods and even within certain methods.