Ammonia volatilization from freshwater fish ponds

摘要: This study evaluated ammonia (NH 3 ) emissions to the atmosphere from fishpond waters and uneaten, floating feed. Channel catfish (Ictalurus punctatus) were stocked at 550 pond -1 in four, 400-m 2 ponds Auburn University Fisheries Research (AUFRU), Auburn, AL, on 30 May 1997. Feed (28% crude protein), prepared as pellets was applied daily. Ponds harvested between 7 9 Oct. Ammonia traps placed a weather vane sampler. measured June through September In addition, NH volatilization wetted feed laboratory experiment. Average ranged 8.8 71.0 mg -N m d , averaged 3.75% of total nitrogen (TAN) concentration water. Positive linear correlations found amount TAN water volatilization. Volatilization not major loss atmosphere. The suggested that 24 kg ha N lost 23 1997 Sept. into which 158 applied. USA, there are about 66 000 ponds. Extrapolation this suggests 1584 t could volatilize each summer.