Study On The Mechanism Of Rice-fish Culture In Yinchuan Land-based Ecological Fishery System

The comprehensive cultivation of rice and fishery is a new agricultural model that has been improved,optimized,promoted,practiced and developed over the years based on traditional rice farming in China.It was first proposed by the team of Academician Zhang Hongcheng of Yangzhou University.Compared with traditional rice farming,the new rice-fishing comprehensive breeding model has highlighted three characteristics of grain-based,ecological optimization and industrialization development.According to different types of culture,the comprehensive breeding of rice and fish can be divided into rice-fish farming,rice-shrimp farming,rice-shrimp farming,etc.,which is a new agricultural sustainable development model of"one water,one field,multiple harvests,ecological circulation,high efficiency and energy saving".The rice-fishing cooperative system is a highly efficient constructed wetland ecosystem.This ecosystem that allows animals and plants to coexist is stronger than the ecosystem of rice cultivation alone.It combines purification capacity and resource production capacity to become the main rice producing area.It has changed the way of agricultural production,improved the ecological benefits of agriculture,developed the rural economy,and achieved a strong grip on rural revitalization.Practice has proved that the comprehensive cultivation of paddy fields has good economic and ecological benefits,and can reduce the amount of rice fertilizer and pesticides,and achieve green and efficient production.The climate and geological conditions vary from place to place.The successful experience of one place cannot be easily realized in other places.According to the actual situation of production,each place needs to select the breeding mode suitable for local natural conditions through demonstration application practice.In this paper,we use the Ningxia Yinchuan Guangming Fishing Ground Base as a test base,from the rice-fish farming system,the circulation and water quality of grass carp in the rice-fish farming system,the water quality and soil change,and the rice-fish farming system.Provide technical support and guidance for the artificially constructed composite rice fishery production system for further development.?.In the rice-fish farming system,the yield and quality of grass carp in the circulating water culture ponds are changed.This paper studies the grass carp production and water quality changes in the two sets of in-pond raceway systems in Guangming Fishing Ground in 2017 and 2018.Among them,grass carp production reached 68.1Kg/m³ in 2017 and 76.8kg/m³ in 2018;during the whole culture period,the water quality in the water tank and the outer pond of the flow tank remained good,the use of fish medicine such as"improving pond bottom sediment and regulating water environment"is extremely rare;the appliacation of modern fishery Internet of Things provides security guarantee for the whole aquaculture process,gradually realizes the water quality monitoring and intelligent management in the production area,reduces the cost of aquaculture,and improves the quality and safety of the aquatic products.Compared with the traditional aquaculture mode,the mode of in-pond raceway system is a more efficient,ecological and environmentally friendly new aquaculture mode.?.In the research on water quality and soil change in the rice-fish farming system,this study selected three experimental plots of rice blast system,rice-crane system and rice-fish system as the experimental field in Guangming fishery base.5 to 8 months,5times,the study was carried out in three experimental plots using circular ditch water samples,ring ditch mud and paddy soil mud samples.According to the investigation report on the production and operation of the rice-fishing comprehensive breeding model households in Ningxia in 2017,combined with the Guangming fishery base and the surrounding growers,the rice yield per mu is about 600 under the rice-fishing comprehensive breeding model without considering the government subsidies.Kilograms/mu,aquatic products are about 60 kilograms/mu,and the income is 2,880yuan.Under the traditional rice single cropping mode,the yield per mu of rice is 700kilograms,and the income is 1820 yuan.Under the same conditions,although the rice-fishing comprehensive breeding model is more traditional than the traditional rice single-cropping model,it will invest 550 yuan/mu in land rent,aquatic product seedlings,labor costs,etc.,and the net profit will be 450 yuan/mu..This project realizes that all aquaculture water bodies are recycled in the system,and are not discharged into the external environment.Only by supplementing the Yellow River water source,the large coupling of rice planting and aquaculture systems can be realized,and the goal of high yield and high ecology can be achieved.?.Stable isotope characteristics of major cultured fish in the rice-fish farming system:In the study of stable isotope characteristics of the main cultured objects in the rice-fish farming system,this study studied five rice-fish farming systems from the Guangming fishery in Yinchuan City?rice loach system,rice shrimp system,rice crab system and two rice fish?.A total of 148 species?detection isotope 88?and 10 species of biological species were sampled.The biological?¹³C value ranged from-28.39‰²0.95‰,and the?¹⁵N value ranged from 4.41‰¹4.49‰.Among them,the lowest?15N value is the squid,and the highest is the black carp,which belongs to the rice fish system,indicating that the living environment and feeding of squid and black carp are different.The lowest?¹³C is silver carp?Hypophthalmichthys molitrix?,which appears in rice fish ponds.The highest is crab?Procambarus clarkia?,which appears in rice crab ponds;the lowest?¹⁵N is cyprinoid?Cyprinus carpio?.In the rice pond,the highest is the snakehead?Channa argus?,which appears in the rice shrimp pond.The trophic level ranges from 1.54⁴.54,mainly between 2.5³.8.The average trophic level of fish is 3.0.Among them,Taiwan's loach and the different breeding silver carp“in Section III”have the lowest nutritional level,and the highest is 4.54 for snakehead scorpio?Channa argusLucioperca lucioperca?.Fish with a trophic level greater than 2.5accounted for 79%of the total.In sequence,the order?Latin?for Lucioperca lucioperca>Hypophthalmichthys molitrix>Erythroculter mongolicus?Basilewsky?>Aristichthys nobilis>Procambarus clarkia>Eriocheir sinensis>Carassiusauratus gibelio“in Section III”>Paramisgurnus dabryanus.This study aims to provide basic scientific information for the major organisms in the system in order to provide scientific reference for further study on the trophic structure of fishery resources in Land-based ecological fisheries system in Yinchuan.The innovation of this research is to combine the traditional pond culture with the comprehensive cultivation of paddy fields,plant the rice with the fertilizer water of the pond,and raise the fish with the clean water purified by the rice fields,so as to achieve the goal of high-yield,high-efficiency and eco-friendly.Studies have shown that the nitrogen content of the feed is about 20²7%,and the phosphorus content is about8²4%.Most of it is deposited and wasted in the pond.The removal rate of nitrogen and phosphorus in rice pond water by rice in rice fields is very high,reaching more than70%.After two years of experiments at the Yinchuan Guangming Fishing Ground Base,our innovative integrated production model is a new model of high productivity,high efficiency and environmental protection,which is worthy of further promotion and further research.