中华绒螯蟹有机和常规养殖池塘底泥氮磷溶出特性研究

A study on the dissolution characteristics of nitrogen and phosphorus from sediments in organic and conventional crab pond farming system

采用室内模拟研究的方法,研究中华绒螯蟹(Eriocheir sinensis)有机和常规养殖底泥中氮、磷的溶出规律。结果显示:有机组氨态氮溶出总量明显高于常规组,覆水前期,底泥厚度是决定氨态氮溶出总量的主要因子,中后期底泥类型成为主要因素。相同厚度底泥中有机组硝态氮的污染负荷明显低于常规组。常规组较有机组更容易在短时间内溶出硝态氮和亚硝态氮。5 cm和10 cm底泥厚度下有机组溶出总磷量分别高于常规组60.5%和56.5%,但在前4 d有机组的溶出速率低于常规组,应提早换水以有效控制总磷浓度。

A laboratory simulation was used to compare the dissolution characteristics of nitrogen and phosphorus from sediments in organic and conventional crab （ Eriocheir sinensis ） farming system. The results showed that the total dissolution quantity of NH4^＋ -N from the sediment of organic crab farming system was distinctively larger than the conventional one. In the early part of the experiment, the organic group with sediment thickness of 10 em demostrated larger NH4^＋ -N dissolution potential than the conventional group with sediment thickness of 5 cm. But the sediment type became the major influencing factor later. With the same sediment thickness, the organic farming system demonstrated smaller NO3^- -N pollution capacity than the conventional one. No matter what thickness of the sediment （5 cm or 10 cm）, NO3^- -N and NO2^- -N from the sediment of conventional farming systemn was dissolved easier than the organic one in a short period of time. But it is reversed for total phosphorus with sediment thickness of 5 cm. And during the first 4 days, the total phosphorus dissolution rate of the organic farming sediment was lower than the conventional one.