Researches On The Symbiosis Technical Model In Pond Fishery

This experiment takes fish vegetable symbiosis technology as the theoretical technology.From April to October 2021,the floating beds of water spinach and rice with 20%coverage were set up in the breeding pond of baquhe Technology Co.,Ltd.in Wangcheng District,Changsha City,Hunan Province.The effects of different floating beds on water quality and floating organisms were explored by regularly and regularly detecting the changes of water quality and plankton;By calculating the production benefits of fish turtle vegetable symbiosis pond,fish turtle rice symbiosis pond and control pond,this paper explores the role of symbiosis system in improving economic,ecological and social benefits,so as to provide some technical reference and theoretical basis for the popularization and application of fish turtle vegetable symbiosis mode and fish turtle rice symbiosis mode in pond breeding mode.The main results of the test are as follows:After the biological floating bed was set in the pond,the transparency of watercress floating bed was significantly improved（P<0.05）,and the transparency of rice floating bed had no significant change（P>0.05）.The do contents of watercress floating bed and rice floating bed in the pond were 3.94mg/l and 3.22mg/l respectively,which were significantly higher than those in the control pond（P<0.05）;The removal rates of NH₄⁺-N,NO₂^--N,PO₄^3--P,TN and TP by floating bed water spinach were 68.8%,65.8%,82.7%,14.6%and 46.9%respectively.The removal rates of NH₄⁺-N,NO₂^--N,PO₄^3--P,TN and TP by floating bed rice were 37.7%,35.5%,81.8%,5.29%and 37.7%respectively.During the whole test period,the average contents of NH₄⁺-N,NO₂^--N,PO₄^3--P,TN and TP in the test pond with floating bed were significantly lower than those in the control pond（P<0.05）.With the progress of the experiment,the dominant species of phytoplankton in the two test pools are mainly diatoms and green algae such as Synedra,Nitzschia and Scenedesmus,while the dominant species of phytoplankton in the control pool are cyanobacteria such as merismopedia and gomphosphaeria.The setting of biological floating bed effectively inhibits the excessive growth of cyanobacteria,It has a good promoting effect on water body;The Shannon Wiener diversity index H of zooplankton and Pielou evenness index J of zooplankton and plants in the test pool are significantly higher than those in the control pool（P<0.05）.The setting of biological floating bed will make the ecosystem of aquaculture water more stable.Both watercress floating bed and rice floating bed can effectively improve the water quality of aquaculture water,but generally speaking,watercress floating bed has a better effect on water quality than rice floating bed.The results show that the average yield of aquatic products in the comprehensive cultivation mode of fish-turtle is 1546 kg per mu and the average profit per mu is 12300yuan;In the fish-turtle-vegetable symbiosis model,the average yield of aquatic products per mu is 1552.2 kg,the average yield of aquatic cash crops per mu is 313kg,and the average profit per mu is 13300 yuan;In the fish-turtle-rice symbiosis model,the average yield of aquatic products per mu is 1522.8 kg,the average yield of aquatic cash crops per mu is 230 kg,and the average profit per mu is 12900 yuan.The comparative analysis shows that the economic benefits of the fish-turtle-vegetable symbiosis model and the fish-turtle-rice symbiosis model increase the additional income of 600～1000 yuan per mu of aquatic cash crops compared with the traditional fish turtle mixed culture model.Fish-turtle-vegetable symbiosis model and fish-turtle-rice symbiosis model play a significant role in improving benefits.