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ARS Home » Pacific West Area » Kimberly, Idaho » Northwest Irrigation and Soils Research » Research » Publications at this Location » Publication #227319
Title: Case Study: On-Farm Evaluation of Liquid Dairy Manure Application Methods to Reduce Ammonia Losses

Author
item Leytem, April
item Bjorneberg, David - Dave
item SHEFFIELD, R - LOUISIANA STATE UNIV.
item DE HARO MARTI, M - UNIVERSITY OF IDAHO

Submitted to: Professional Animal Scientist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/1/2008
Publication Date: 2/1/2009
Citation: Leytem, A.B., Bjorneberg, D.L., Sheffield, R.E., De Haro Marti, M.E. 2009. Case Study: On-Farm Evaluation of Liquid Dairy Manure Application Methods to Reduce Ammonia Losses. The Professional Animal Scientist. 25:93-98.

Interpretive Summary: Intensification of the dairy industry in southern Idaho has led to greater land application of manures. The volatilization of ammonia from land applied manure is not only a loss of valuable nitrogen but also an air quality concern as ammonia plays a role in the formation of PM-2.5 and PM-10 airborne particulates which can be a health hazard. The goal of this study was to determine relative differences in potential ammonia losses from land application of liquid dairy manure via three methods: surface application, Aerway incorporation, and subsurface injection. Liquid manure was applied at a rate of 190 cubic meters per hectare on four producers’ farms with average nitrogen and phosphorus application rates ranging from 28 to 130 kg nitrogen per hectare and 6 to 36 kg phosphorus per hectare, respectively. Each plot was approximately 120 x 120 m with three towers set approximately 15 m apart in a line across the center of the plots perpendicular to the prevailing wind direction. Ambient average ammonia concentrations were measured with passive samplers for three days following manure application at three heights (1, 2, and 4 m). Data were analyzed using a full factorial model that included application method, sampler height, day and their interactions as fixed effects with farm as a random effect. The ambient average concentrations of ammonia ranged from 0.03 to 0.21 mg ammonia nitrogen per cubic meter over the three day period. There was a significant main effect of sampler height, day, and application method. Ambient ammonia concentrations decreased with increasing height above the plots, suggesting that placing samplers at lower heights is advisable to increase measurement sensitivity. The greatest ammonia concentrations were found during the first 24 h following manure application and were significantly lower after 48 h. When concentrations measured at 1 m were averaged over 48 hrs, treatments followed the trend: surface = Aerway > injection = control with a 67% decrease in ammonia concentration when liquid manure was injected vs. surface or Aerway application. Subsurface injection was the best method of liquid manure application for minimizing ammonia losses. The timeliness of incorporation is also crucial with the greatest decrease in potential ammonia losses resulting from deeper incorporation as close to the application time as possible.

Technical Abstract: Intensification of the dairy industry in southern Idaho has led to greater land application of manures. The volatilization of ammonia from land applied manure is not only a loss of valuable nitrogen but also an air quality concern as ammonia plays a role in the formation of PM-2.5 and PM-10 airborne particulates which can be a health hazard. The goal of this study was to determine relative differences in potential ammonia losses from land application of liquid dairy manure via three methods: surface application, Aerway incorporation, and subsurface injection. Liquid manure was applied at a rate of 190 cubic meters per hectare on four producers’ farms with average N and P application rates ranging from 28 to 130 kg N per hectare and 6 to 36 kg P per hectare, respectively. Each plot was approximately 120 x 120 m with three towers set approximately 15 m apart in a line across the center of the plots perpendicular to the prevailing wind direction. Ambient average ammonia concentrations were measured with passive samplers for three days following manure application at three heights (1, 2, and 4 m). Data were analyzed using a full factorial model that included application method, sampler height, day and their interactions as fixed effects with farm as a random effect. The ambient average concentrations of ammonia ranged from 0.03 to 0.21 mg NH3-N per cubic meter over the three day period. There was a significant main effect of sampler height (P = 0.0005), day (P = 0.0004), and application method (P = <0.0001) with all interaction terms being insignificant. Ambient ammonia concentrations decreased with increasing height above the plots, suggesting that placing samplers at lower heights is advisable to increase measurement sensitivity. The greatest ammonia concentrations were found during the first 24 h following manure application and were significantly lower after 48 h. When concentrations measured at 1 m were averaged over 48 hrs, treatments followed the trend: surface = Aerway > injection = control with a 67% decrease in ammonia concentration when liquid manure was injected vs. surface or Aerway application. Subsurface injection was the best method of liquid manure application for minimizing ammonia losses. The timeliness of incorporation is also crucial with the greatest decrease in potential ammonia losses resulting from deeper incorporation as close to the application time as possible.