Ammonium phosphate (16% N and 48% P2O5) and ammonium sulfate (21% N) were the sources
of nitrogen and phosphorus. Amounts of fertilizer for each pond (Table 1) were weighed and transferred to 20 L of pond water in a plastic bucket, water and fertilizer were stirred thoroughly, and the slurry was splashed over the pond surface. Fertilizers were applied five times at 3-wk intervals between December 10, 2008 and April 4, 2009.