291-6 Manure Application Method and Timing Effects On Emission of Ammonia and Nitrous Oxide.

See more from this Division: S06 Soil & Water Management & Conservation
See more from this Session: Nitrogen-Use Efficiency, Nitrogen Leaching, and Nitrous Oxide Emissions As Influenced by Management Practices: I
Tuesday, October 23, 2012: 9:35 AM
Duke Energy Convention Center, Room 202, Level 2
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William Jokela1, Carrie Laboski2 and Todd Andraski2, (1)USDA-ARS, Marshfield, WI
(2)Soil Science, University of Wisconsin, Madison, WI
Manure is a valuable source of N for crop production, but gaseous losses of manure N as ammonia (NH3) and nitrous oxide (N2O) reduce N available to the crop, adversely affect air quality, and contribute to increased greenhouse gas emission. We conducted a field study on corn to evaluate the effect of liquid dairy manure applied pre-plant (injection or 1-h or 3-day disk incorporation) or sidedressed at 5-leaf stage (injected or surface-applied) on emission of NH3 and N2O. Manure was applied at a rate of 60 m3 ha-1, which supplied an average of 170 kg ha-1 of total N and 70 kg ha-1 of NH4-N. Ammonia emission was measured for 3 d after manure application using the dynamic chamber/equilibrium concentration technique, and N2O flux was quantified using the static chamber method at intervals of 3 to 14 d throughout the season. Ammonia losses were 20 to 50 kg N ha-1 from pre-plant surface application (30 to 60 % of applied NH4-N), most of the loss occurring in the first 12 h after application. Emission rates were reduced by as much as 75% by 1-h disk incorporation and over 90% by injection. Losses of N2O were relatively low, but pronounced peaks of N2O flux occurred from either pre-plant or sidedress injected manure in different years. Results show that NH3 emission from manure can be reduced substantially by injection or quick incorporation, but there may be some tradeoff with N2O flux from injection.
See more from this Division: S06 Soil & Water Management & Conservation
See more from this Session: Nitrogen-Use Efficiency, Nitrogen Leaching, and Nitrous Oxide Emissions As Influenced by Management Practices: I