How to Do Ecological Fish Farming? A Detailed Guide to Practical Farming Techniques
Ecological fish farming is an excellent farming method. Ecological fish farming makes use of the material cycles and energy conversion relationships between organisms and environmental factors, as well as between organisms and organisms, within the aquaculture ecosystem, and applies purposeful artificial regulation to establish a new ecological balance, so that natural resources can be used effectively and the ecological, economic and social benefits of aquaculture can be fully brought into play. Rice-fish farming technology can reduce the use of herbicides, insecticides and chemical fertilizers in the rice-growing process, achieving the effect of lowering costs and reducing pollution; it is a set of high-yield, high-quality, low-consumption, high-efficiency aquatic agricultural ecological systems. Let us now look at the specific farming techniques, shall we?
Specific Farming Techniques for Ecological Fish Farming
1. Site selection: A pond is the place where fish live, and the quality of the pond conditions has a direct impact on fish yield. When choosing a site for pond construction, the principle that must be grasped is to select fields or mountain-valley fields that are broad and flat in geographical location, with abundant and pollution-free water sources; the water in the pond should be easy to drain and irrigate, and not prone to flooding; at the same time, the location should have good sunlight and convenient transportation, power supply and other conveniences.
2. Planning: For pond construction, planning must come first. The selected fields or mountain-valley fields must undergo unified planning, with good planning of the locations of roads, ponds, pig pens, duck houses, goose houses, biogas digesters and the living quarters of workers, etc. Road construction must surround the pond on all sides: on the one hand, it facilitates infrastructure construction, such as transporting bricks, erecting utility poles and stringing wires, etc.; on the other hand, it facilitates putting in fish feed, night patrols, observing fish movements and loading fish onto trucks when catching them. Properly planning the roads, pig pens, ponds, etc. makes it convenient to feed the fish with feed, and all pig manure can be discharged into the pond.
3. Building the pond: Pond construction should be adapted to local conditions. According to the size of the field, ponds of 3-5 mu each, or 8-10 mu or more, can be built; or in mountain-valley fields, the narrow mouth of the mountain-valley field can be used to build a fish pond dam along the mountain, directly creating fish ponds of 10-30 mu each or larger. The construction of fish ponds must be divided into duckweed ponds and fish-rearing ponds; the duckweed pond should account for one third of the total fish pond area, and the fish-rearing pond should account for two thirds; the water depth of the pond must not be less than 1.8 m; the fish pond dam must use yellow soil from the mountain side as the main material; when building the dam, the silt at the bottom must be cleaned out thoroughly; the dam slope should be made into a 45-degree incline; the dam construction height should reach 2 m or higher, but flood control and other issues must be taken into account; the bottom of the dam should be 6-8 m wide, and the top 2-4 m wide; if building a pond of 3-5 mu, it can be built according to the actual situation; during the construction of each pond, flood discharge facilities must be built, a drainage pipe with a diameter of 20 cm must be embedded in the bottom, and a flood discharge ditch should be built at the top of the dam near the mountain side according to geographical conditions and water flow, to avoid unnecessary losses caused by poor management when rainstorms come.
Aeration facilities: There are two ways to add oxygen for fish: first, electric aeration, for which a 1.5 kW or 3 kW aerator can be chosen; each 1.5 kW aerator can supply oxygen for fish in a 3 mu pond, and each 3 kW unit can supply oxygen for fish in a 10 mu pond; second, spring-water aeration. In places without electricity, mountain spring water can be piped into the center of the fish pond as an aeration facility; the aeration water pipe should be 1.5-2 m above the pond water surface, and pouring it into the pond can produce an aeration effect. When aeration is not needed, the water should be blocked off, to avoid excessive water in the pond causing loss of nutrients.
4. Building pens: Build the pig pen in the upstream position of the pond, and build the biogas digester between the pig pen and the duckweed pond. Pig manure is directly washed into the biogas digester; the biogas can be used to warm the pigs or for people to cook and for lighting; the biogas slurry flows into the pond as fertilizer for the duckweed, so the environment will not be polluted. The duck house and goose house are built directly on the water surface of the duckweed pond, and the manure goes directly into the duckweed pond and serves directly as nutrients for the duckweed. Because of the large temperature difference between day and night, duckweed grows quickly, and with sufficient fertilizer, the duckweed grown in one third of the duckweed pond area can supply natural feed for the grass carp, the main fish, in two thirds of the fish pond area; the fish raised this way have no earthy taste, no pollution and no drug residues. Fish farmed by this method can only be achieved in the inland areas. 4. Duckweed: Due to seasonal changes, three kinds of duckweed can grow in the duckweed pond. The first kind of duckweed grows from April to June each year and is called "Qixian duckweed"; it can feed summer-fry fingerlings; the second kind of duckweed grows from June to September each year and is called "hybrid red-bottom duckweed"; it can feed medium-sized fish of 250 g-500 g or more; the third kind of duckweed grows from September to March of the following year and is called "hybrid seven-layer duckweed"; it can feed large fish of 500 g-1000 g or more. Pest and disease prevention and control work for the duckweed must also be done well.
5. Farming:
1. Stocking fry: Before stocking fry, do a good job of pond disinfection. From April to May each year, stock high-quality fry, mainly grass carp summer fry, at 1000 fry per mu of pond; other fish species can be stocked freely according to the actual conditions of the pond.
2. Feeding duckweed: After the early fry are put into the fish pond, feed Qixian duckweed every morning from 7 o'clock to 8 o'clock, and before 4 o'clock in the afternoon supplement with fish feed containing 30% protein; using floating feed allows observation of the fish's growth rate and growth conditions. For fish in the mid and late stages of farming, feed hybrid red-bottom duckweed and hybrid seven-layer duckweed every day at 7-8 o'clock in the morning and before 4 o'clock in the afternoon, ensuring the fish can eat their fill, but not too much.
3. Pond oxygen content: Pay attention every day to observing the oxygen content of the pond. From May to August each year, because the inland areas are at higher altitude, the oxygen released in the fish pond water at night is relatively low, causing fish in the pond to lack oxygen; at this time the aeration facilities must be used.
4. Preventive work: In fish farming, usually disinfect more, prevent disease more, prevent pond fatigue, prevent predators, prevent fish escape and prevent fish theft.
6. Harvesting: When grass carp have grown to about 1000-1500 g, the fish density in the pond is relatively high; use a lift net to catch part of the fish, and raise the remaining fish until before the summer fry are stocked the following year, then use dry-pond harvesting; at this time each fish in the pond can reach 3500-5000 g. After all the fish in the pond have been caught, clean the pond and enter the next year's farming.
Introduction to Pond Aquaponics Fish-Vegetable Symbiotic Cultivation Technology
"Pond aquaponics ecological fish-vegetable symbiotic cultivation technology" is based on the living environment, nutritional needs and physical and chemical characteristics of fish and plants, and combines the two different agricultural technologies of aquaculture and vegetable cultivation through scientific ecological design to achieve a new type of composite fish-water-vegetable harmonious, synergistic, symbiotic cultivation model of "raising fish without changing water, growing vegetables without fertilizing." Pond aquaponics ecological fish-vegetable symbiotic cultivation technology makes use of the physiological characteristics of aquatic vegetables, which take root in the fish-rearing water body to grow and need to absorb nutrients from the water body, to convert harmful substances and wastes produced in the fish-farming process (excrement produced by fish farming, leftover feed, ammonia nitrogen, etc.) into nutrients needed for vegetable growth, forming within the pond a circulatory system of "fish fertilize the water - vegetables purify the water - water nourishes the fish," allowing fish and vegetables to achieve a harmonious symbiotic ecological balance. It can not only naturally purify the fish-rearing water body and keep water quality stable over the long term, but also harvest a certain amount of aquatic vegetables while raising fish, with advantages such as water purification, improving aquatic product quality, increasing vegetable income, reducing cost inputs such as water, electricity and drugs, and landscape engineering.
How to Improve the Yield and Benefits of Pond Fish Farming
1. Introduce new farming species. In recent years, the introduction of new species such as tilapia, freshwater pomfret, rainbow sea bream and puffer fish has greatly improved the farming benefits of ponds.
2. Strengthen farming technical measures, adjust the stocking model, promote intensive pond farming technology, and increase yield and benefits. The traditional fish farming model, that is, raising fish with fertilization combined with water injection technology, has achieved fairly good results in fish yield and benefits.
How to Make the Water in a Fish Pond Transparent and Not Green
1. Engineering measures: These include dredging bottom sediment, carrying out deep aeration of the water body, injecting water to dilute it, and laying plastic on the surface of the bottom sediment, etc. Dredging bottom sediment can reduce and even eliminate potential internal pollution sources; deep aeration can regularly or irregularly supplement oxygen by artificial deep aeration at the lake bottom, so that no anaerobic layer appears at the interface between water and bottom sediment and an aerobic state is maintained, which helps inhibit the release of phosphorus from the bottom sediment. In addition, where conditions permit, injecting water with low phosphorus and nitrogen concentrations into the fish pond can play a role in diluting the nutrient concentration.
2. Chemical methods: This is a category of methods including coagulation and sedimentation and the use of chemical agents to kill algae. For example, many kinds of cations can effectively precipitate phosphorus out of aqueous solution, among which the most valuable are the relatively cheap iron, aluminum and calcium, all of which can form insoluble precipitates with phosphate and settle out.
3. Biological measures: Methods that use aquatic organisms to absorb and utilize nitrogen and phosphorus elements for metabolic activities in order to remove nitrogen and phosphorus nutrients from the water body. At present, some countries have begun experimenting with large aquatic plant sewage treatment systems to purify eutrophic water bodies. Large aquatic plants include many species such as water hyacinth, reed, narrow-leaf cattail, Canadian waterweed, spiked water-milfoil, Nitella, and pennywort, etc., and suitable ones can be selected and planted according to different climatic conditions and the nature of the pollutants. The characteristic of aquatic plants purifying water bodies is that large aquatic plants are the main body, and the plants and root-zone microorganisms coexist symbiotically, producing a synergistic effect to purify sewage. Through direct absorption by plants, microbial transformation, physical adsorption and sedimentation, nitrogen, phosphorus and suspended particles are removed, and at the same time there is also a degrading effect on heavy metal molecules.
Ecological fish farming is based on the living environment, nutritional needs and physical and chemical characteristics of fish and plants, and combines the two different agricultural technologies of aquaculture and vegetable cultivation through scientific ecological design to achieve a new type of composite fish-water-vegetable harmonious, synergistic, symbiotic cultivation model of "raising fish without changing water, growing vegetables without fertilizing." Through the above introduction, I believe everyone has gained a certain understanding of ecological fish farming, and I hope you can study the farming techniques well and achieve prosperity.