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Contemporary agriculture is characterized by the intensive production of livestock in confined facilities and land application of stored waste as an organic fertilizer. Emission of nitrous oxide (N₂O) from receiving soils is an important, but poorly constrained term, in the atmospheric N₂O budget. In particular, there are few data for N₂O emissions from spray fields associated with industrial scale, swine-production facilities that have rapidly expanded in the southeastern United States. In an intensive, 24-day investigation over three spray cycles, we followed the time course for changes in N₂O emission and soil physicochemical variables in an agricultural field irrigated with liquid lagoonal swine effluent. The total-N [535 milligrams per liter (mg/L^-1)] of the liquid waste was almost entirely NH₄⁺-N (>90%) and thus had a low mineralization potential. Soil profiles for nitrification and denitrification indicated that >90% of potential activity was localized in the surface 20 centimeters (cm). Application of this liquid fertilizer to warm (19 to 28^oC) soils in a form that is both readily volatilized and immediately utilizeable by the endogenous N-cycling microbial community resulted in a sharp decline in soil NH₄⁺-N and supported a rapid and short-lived (days) burst of nitrification, dentrification, and N₂O emission. Fluxes of nitrous oxide as nitrogen (N₂O-N) as high as 9,200 micrograms per gram dry weight of soil per hour (m g g_dw^-1 h^-1) were observed shortly after fertilization, but emissions decreased to prefertilization levels within a few days. Poor correlations between N₂O efflux and soil physicochemical variables (temperature, moisture, NO₃^--N, NH₄⁺-N) and fertilizer-loading rate point to the complexity of interacting factors affecting N₂O production and emission. Total fertilizer N applied and N₂O-N emitted were 29.7 grams per square meter (g/m^-2), and 395 milligrams per square meter (mg/m^-2), respectively. The fractional loss of applied N to N₂O (corrected for background emission) was 1.4%, in agreement with the mean of 1.25% reported for synthetic fertilizers. The direct effects of fertilizer application appear to be more immediate and short-lived for liquid swine waste than for manures and slurries that have a slower release of nitrogenous nutrients.

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