The nitrification and denitrification rates in the sediments of the feeding and non-feeding areas of the shrimp culture pond were measured by applying acetylene inhibition technique, and the N2O concentration in the surface water was determined by GC-ECD during July～August, 2009. The results showed that the rates of nitrification, denitrification, and nitrate reduction ranged between 10.70～337.47 t μmol/m2 · h, 1.10～17.92 tμmol/m2 · h, 0. 09 ～7.48 mmol/m2 · h respectively. Concentrations of N2O in the surface water was 5.98～10.9 nmol/L and the air-water flux of N2O ranged between 1.76～3.89 μmol/m2 · d. Nitrification and denitrification process in the sediments of the shrimp pond showed both significant regional differences and significant seasonal variations. In mid-August, nitrification and denitrification rates reached the highest values, and in the whole culture period, nitrification rates in the feeding area were 2～10 folds of the non-feeding area, and denitrification rates in the feeding area were 1～4 folds of the non-feeding area. Denitrification played an important role in the nitrogen cycle of the shrimp pond ecosystem, removing inorganic nitrogen at 2. 80 g/d, accounting for 2.34％ of the total input of inorganic nitrogen and 2. 56％ of the total output in the shrimp pond.%2009年7～8月,通过使用乙炔抑制技术对对虾养殖池塘的投饵区和非投饵区沉积物硝化与反硝化速率进行了测定,并同时用气相色谱法测定了虾塘表层N2O浓度.结果表明,虾塘沉积物硝化、反硝化和硝酸盐还原速率分别为10.70～337.47 μmol/m2·h、1.10～17.92 μmol/m2·h、0.090～7.48 mmol/m2·h,虾塘表层N2O浓度为5.98～10.90 nmol/L,海-气交换通量为1.76～3.89μmol/m1·d.虾塘硝化与反硝化作用较为复杂,不仅存在着显著的区域性差异,而且呈现出明显的养殖季节变化特征,其中8月中旬硝化与反硝化速率达到最高值,而在整个养殖季节,投饵区硝化速率约为非投饵区的2～10倍,反硝化速率约为非投饵区的1～4倍.反硝化作用在虾塘生态系统的氮循环中扮演着重要角色,其日无机氮去除量为2.80 g/d,占虾塘无机氮总输入的2.34%,占总输出的2.56%.
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