以缢蛏为主的生态综合养殖池塘氮磷流转研究

The Budgets of Nitrogen and Phosphorus in the Integrated Multi-trophic Aquaculture(IMTA) Ponds

养殖池塘生态系统氮(N)、磷(P)的流转及N、P利用率情况常作为评价池塘养殖模式及其水平的重要指标.以缢蛏(Sinonovacula constrzcta)为主的生态综合养殖池塘为研究对象,于2011年4—11月期间每月测定一个水交换周期内池塘的进排水总磷(TP)、总氮(TN)、叶绿素a(Chl a),根据养殖记录估算以肥料、饲料和养殖动物苗种输入的N、P含量及养殖动物生长积累的N、P含量,评估以缢蛏为主的生态综合养殖池塘N、P流转情况.结果表明:在输入的N中化肥输入比例最高,约占57.0%;水动力交换输入约占12.9%;饲料输入约占24.0%.在输入的P中最主要的输入是化肥和饲料输入,分别为69.3%和16.9%;水交换输入约为11.6%;罗非鱼(Oreochromis niloticus)苗输入1.1%.在N的输出中,最主要的是水动力交换输出,约占66.0%,被收获养殖动物利用的N约为29.6%,其中罗非鱼14.3%,缢蛏11.5%,对虾3.8%.在P的输出中,水动力交换输出约为69.1%,被收获养殖动物利用的P为22.2%,其中罗非鱼占13.4%,缢蛏占7.8%.约有4.5%的N和约8.7%的P通过渗漏或沉积,形成内源污染.

Nitrogen （N） and phosphorus （P） budgets of Sinonovacula constrzcta culture ponds were studied during April to November 2011 to assess aquaculture patterns and quality,total N （TN） and total P （TP） input and discharge.every month in two integrated multi-trophic aquaculture ponds,located in estuary of Zhangjiang River,Zhangzhou City,Fujian Province.Results showed that nitrogen from fertilizer and feed were the main input items,which comprised 570% and 240% of the total input nitrogen,respectively.The largest P input was mainly coming from fertilizer and feed,which accounted for 693% and 169%,respectively.In harvested products,N output was occupied 296% of total output N,within which the harvested Oreochromis niloticus and Sinonovacula constrzcta comprised 143% and 115% respectively.About 66% of the total output N was released from water exchange.Among the items of total P output,the harvested Oreochromis niloticus and Sinonovacula constrzcta comprised of 134% and 78% of total P,respectively.The main item of P outputs was water exchange,which comprised 691% of the total output P,however the loss through seepage comprised the smallest percentage of the total output of N and P,which accounted for 45% in N and 87% in P,in the last,becoming the internal source of pollution in the ponds.