IMPACT OF LAND APPLICATION METHOD ON AMMONIA LOSS FROM HOG LAGOON EFFLUENT

Ammonia volatilization during land-application of hog lagoon effluent can adversely affect public health and the environment. Ammonia losses front hog lagoon effluent applied to Coastal Bermudagrass with the drag-hose (two applications) and traveling gun (three applications) were measured in spring and summer of 2006. Ammonia losses during application with the traveling gun were measured with acidified catch cans while losses during (traveling gun) or following (drag-hose) application for up to 96 h was measured with a micrometeorological method, the integrated horizontal flux (IHF) method; ammonia-N losses measured with the IHF, method and catch cans are not additive. Ammonia-N losses during application with the traveling gun ranged between 3.8% to 9.2% of total ammoniacal nitrogen (TAN) applied, increasing with wind speed and decreasing relative humidity. For two applications,, average ammonia loss with the drag-hose was <25% of the traveling gun. Ammonia-N losses front the traveling gun and drag-hose averaged 46.3% (n = 3) and 5.5% (n = 2), respectively, of the TAN applied. Ammonia-N loss during the first 4 h, as percent of total TAN loss was higher with the traveling gun. Whereas traveling gun ammonia losses were affected more by weather (e.g., relative humidity) and crop height, drag-hose losses were impacted more by effluent properties. Wind speed measurement contributed to <6% uncertainty in ammonia loss for both systems during one 4-h period. There, are also other sources of uncertainty. Results front this study are comparable with published micrometeorological studies on hog lagoon effluent application.