有效微生物(EM)在中华绒螯蟹养殖中的应用

为探讨有效微生物( EM)对蟹塘水质和螃蟹成活率的改善作用,在南京市高淳区螃蟹文化园开展了EM应用试验研究。试验结果表明：在中华绒螯蟹养殖过程中投加EM,能有效降低水体中污染物的质量浓度,提高螃蟹成活率,但EM投加质量浓度不宜过大。当籽( EM)=1.5 mg/L时,蟹塘水体中NH+4-N、NO-2-N、COD和TP的质量浓度比不投加EM的对照塘降低12.7%~29.2%,螃蟹成活率提高2.4%；籽( EM)=6.0 mg/L时,NH+4-N、COD和TP的质量浓度分别降低1.1%、14.4%、0.03%,而NO-2-N 升高15.6%,螃蟹成活率升高1.0%。由此可见,当 EM 投加质量浓度过高(6.0 mg/L)时,水质指标及成活率改善效果不如EM投加质量浓度较低时(1.5 mg/L),且会引起NO-2-N的累积。

Application of effective microorganisms(EM)to Eriocheir sinensis culture

In order to explore the effects of effective microorganisms(EM)on the improvement of water quality of crab ponds and survival rate of crabs, an experimental study on EM application was conducted in the Crab Cultural Park in the Gaochun District of Nanjing City. The results show that applying EM to Eriocheir sinensis culture can effectively decrease the concentration of pollutants in the water and increase the survival rate of crabs, but overdoses of EM should be avoided. With an EM concentration of 1. 5 mg/L in the crab pond, the concentrations of NH⁺₄-N, NO^-₂-N, COD, and TP decreased by 12. 7% to 29. 2%, and the survival rate of crabs increased by 2. 4%, compared with the control group. However, when the concentration of EM in the crab pond increased to 6. 0 mg/L, the concentrations of NH⁺₄-N, COD, and TP decreased by 1. 1%, 14. 4%, and 0. 03%, respectively, while the concentration of NO^-₂-N and the survival rate of crabs increased by 15. 6% and 1. 0%, respectively. A high EM dosage of 6. 0 mg/L resulted in poorer performance in improving the water quality and survival rate than a small EM dosage of 1. 5 mg/L, and even caused accumulation of NO^-₂-N.