341-9 Measurement of NH3 Emission At Dairy Lagoon Water Application Sites.



Wednesday, October 19, 2011: 10:25 AM
Henry Gonzalez Convention Center, Room 007B, River Level

Sang R. Lee, Scott R. Yates and Scott A. Bradford, USDA-ARS, U.S. Salinity Laboratory, Riverside, CA
Nutrient management plans (NMPs) for field-scale application of dairy lagoon water to crops require information about volatilization losses of NH3. Equilibrium models are commonly used to estimate NH3 emissions from lagoon water. However, such models do not always accurately reproduce observed NH3 emissions, which may be partly due to an incomplete mechanistic understanding of NH3 production. In this study, NH3 emissions from three different liquid sources [(pure solutions of (NH4)2SO4 (AS), dairy anaerobic lagoon liquid (DALL), and recycled water constituents (RWC)] were measured using a small flow-through chamber and acid-trap technique.  Emissions from DALL and RWC were compared with similar results from pure (NH4)2SO4 solutions, and relationships between NH3 flux and pH, temperature, and total ammoniacal nitrogen (TAN) under controlled conditions were investigated. The NH3 flux was found to vary linearly with the TAN concentration. Information gathered by this study will facilitate the application of Eddy covariance flux measurements to quantify NH3 losses from dairy lagoon water and agricultural fields under NMP conditions.
See more from this Division: S01 Soil Physics
See more from this Session: Measurement and Modeling of near-Surface Soil Water and Energy Fluxes: I