Closed polyculture of Chinese penaeid shrimp,Taiwan red tilapia ,and molluscans(constricted tagelus and bay scallop) was studied from 1995 to 1997 with the enclosure experiment method, on a shrimp farm in Haiyang Coun...Closed polyculture of Chinese penaeid shrimp,Taiwan red tilapia ,and molluscans(constricted tagelus and bay scallop) was studied from 1995 to 1997 with the enclosure experiment method, on a shrimp farm in Haiyang County,Shandong Province. Four structure optimized closed polyculture systems, i.e., the “shrimp tagelus" system, the “shrimp scallop" system,the “shrimp tilapia" system and the “shrimp tilapia tagelus" system,were worked out. All these polyculture systems were superior to shrimp monoculture system in economic and ecological efficiencies. The order of these polyculture systems in efficiencies was “shrimp tilapia tagelus">“shrimp tagelus">“shrimp tilapia">“shrimp scallop". The “shrimp tilapia tagelus" system raised the production by 28% and the utilization efficiency of input nitrogen by 85%.These closed polyculture systems reduced the nitrogen discharge ratio to 6%-8%, instead of 40%-90% in the usual open culture systems. The ecological features of the systems were also investigated and many meaningful results have been obtained. The mechanism enhancing the efficiencies of these systems, the ways to enhance the efficiencies further and those to reuse the sedimented materials are disscussed.展开更多
基金Project3 94 3 0 1 50supportedbyNSFC .WorkalsosupportedbytheNationalKeyProgramfortheNinth Five Year PlanunderGrantNo.96 92 2
文摘Closed polyculture of Chinese penaeid shrimp,Taiwan red tilapia ,and molluscans(constricted tagelus and bay scallop) was studied from 1995 to 1997 with the enclosure experiment method, on a shrimp farm in Haiyang County,Shandong Province. Four structure optimized closed polyculture systems, i.e., the “shrimp tagelus" system, the “shrimp scallop" system,the “shrimp tilapia" system and the “shrimp tilapia tagelus" system,were worked out. All these polyculture systems were superior to shrimp monoculture system in economic and ecological efficiencies. The order of these polyculture systems in efficiencies was “shrimp tilapia tagelus">“shrimp tagelus">“shrimp tilapia">“shrimp scallop". The “shrimp tilapia tagelus" system raised the production by 28% and the utilization efficiency of input nitrogen by 85%.These closed polyculture systems reduced the nitrogen discharge ratio to 6%-8%, instead of 40%-90% in the usual open culture systems. The ecological features of the systems were also investigated and many meaningful results have been obtained. The mechanism enhancing the efficiencies of these systems, the ways to enhance the efficiencies further and those to reuse the sedimented materials are disscussed.
