Knowledge of fish culture in reservoir

Now many people are starting to raise fish in the countryside, and many people are building a reservoir in the countryside, but there are also a lot of exquisite fish farming in the reservoir. Let's learn about the relevant knowledge with Xiaobian, hoping to help the new aquaculture friends.

Knowledge of fish culture in reservoir

1. Release varieties: the purpose of applying chemical fertilizer is to fertilize water and breed plankton, so the reservoir is mainly rich and watery, such as silver carp, silver carp and so on, with grass, weave and herring properly.

2. The proportion of putting in: fat water fish accounts for 80% muri 90%, other fish accounts for 10% muri 20%.

3. Release time and specifications: the large size fish species are more than 13.20 cm, and 0.05ml 0.10 kg / tail is suitable, which should be put into the reservoir in autumn, winter and spring. The best summer flower fish species should be more than 6.60 centimeters, which should be put into the reservoir in late May and early July, which should be divided into 2-3 batches.

4. the quantity of seed input is determined according to reservoir conditions, technology, funds and other factors. Generally invest more than 13.20 cm large size fish 500-600 / mu, interbreed more than 6.60 cm summer flower fry 500-800 / mu.

How to fertilize fish culture in reservoir

1. Fertilization time: chemical fertilizer can be released when the water temperature reaches 18 degrees Celsius. The fertilization time is generally from mid-April to late October.

2. types of chemical fertilizers: the chemical fertilizers tried out in the reservoir are nitrogen fertilizer and phosphate fertilizer.

3. Considering the ratio of nitrogen and phosphorus fertilizer efficiency and fertilizer price, ammonium chloride and calcium superphosphate, or ammonium bicarbonate and calcium superphosphate are generally applied.

4. The amount of fertilization: according to the experiment, when the content of nitrogen in the reservoir water reaches 2 mg / L, the plankton biomass reaches more than 20 mg / L, which meets the requirement of high yield.

5. Water color and transparency: after fertilization, the water color of water fertilizer is oil green or dark green. The transparency is 15-25 cm.

Matters needing attention in fertilization

1. Master the order of fertilization: the order of applying chemical fertilizer is to apply phosphate fertilizer first and then nitrogen fertilizer, which can not be reversed. Nitrogen and phosphorus fertilizer can not be mixed together, otherwise the fertilizer effect will be lost.

2. Choose good weather: it is better to apply fertilizer in sunny days.

3. It is necessary to apply a small amount of fertilizer for many times: when water and fertilizer is used, plankton is rich, and nutrients should be replenished in time, which can not only make the fertilizer applied into the water be quickly absorbed and utilized, improve the fertilizer efficiency, but also be conducive to the rapid reproduction and growth of plankton. Provide rich and stable food for fish production. Do not fertilize when the water is thin, otherwise you need a lot of topdressing water to become fertilizer, and delay the production time, increase the coefficient of chemical fertilizer, increase the cost and affect the benefit.

4. It is necessary to cast a good spell: it is usually cast in the upwind and shallow water of the reservoir. Nitrogen and potassium fertilizer water is fully soluble, sprinkled evenly, and the ship is S-shaped.

5. Proper application of quicklime to regulate water quality: long-term application of chemical fertilizer turns sour water quality. From May to August, quicklime should be applied once a month, 15-20 kg per mu each time, so that the calcium content of the reservoir water can reach more than 100 mg / L (preferably 120-180 mg / L). And quicklime is used to meet the calcium requirements for bone growth of plankton and fish.

Fish culture in small reservoirs generally ranges from tens of mu (1 mu = 1 hectare) to hundreds of mu, with a water depth of about 10 meters, and rich in dissolved oxygen and bait.

Management techniques of fish culture

First, with reasonable collocation, the timely stocking reservoir has more enemy damage than the pond, the bait foundation is poor, the ability of small fish species to escape enemy damage is poor, and the feeding ability is also low, so if the size of the stocking fish species is too small, the survival rate will be lower. Generally, large size fish species of more than 13 centimeters should be released in order to achieve higher recapture rate and commodity rate. In terms of breed matching, silver carp and bighead carp should be mainly cultivated with chemical fertilizer, which can account for more than 90% of the total fish production, and the proportion of silver carp and bighead carp is 4 ∶ 1. With grass, carp and crucian carp accounted for 20% and 30%.

The stocking density of the reservoir should be determined according to the number of bait organisms in the water and the number of fertilizers, generally 200 to 500 per mu, which can reach the commercial specifications in the same year. When the fish species are put into the reservoir, it is better to release them in autumn and winter, which can make the fish species adapt to the living environment of the large water surface in advance. At the same time, due to the weakening of the activity ability and food intake of ferocious fish in winter, it is helpful to improve the survival rate of fish species. The delivery site should be placed in the upstream shelter from the wind and the sun, at different points, and must not be placed near the dam or drainage sluice.

Second, to master the reasonable amount of fertilizer application, the application amount should be determined according to the situation of the water body and different seasons, and the transparency after application should be 25cm, 30cm, yellowish brown or brownish green. From April to May, organic fertilizer was applied mainly with 250kg / mu and inorganic fertilizer at the same time, and from June to August, inorganic fertilizer was mainly applied with mixed application of nitrogen and phosphorus fertilizer, the ratio was 2 ∶ 1, nitrogen fertilizer 1.5 ~ 2.5kg / mu, phosphorus fertilizer 2.5kg / mu, once every 10 ~ 15 days.

Urea or ammonium bicarbonate is the main nitrogen fertilizer, and calcium superphosphate is the main phosphate fertilizer. Phosphate fertilizer is applied first, and then nitrogen fertilizer is applied, which can not be reversed so as not to cause dead fish. The choice of fertilization is in sunny days, and the sprinkling method should be used in the upper and middle reaches of the reservoir in the shallow water area, and the overgrown areas of water and plants should be avoided. It is not applied in the downstream deep water area and near the dam.

Third, the prevention of fish disease is more important than the treatment of fish species must be disinfected before release; usually sprinkle with quicklime or bleach in the whole bank, adjust the water quality regularly in the high temperature season, and treat fish diseases in time when they are found. Generally, rotten gills and printing diseases often occur, and there are anchor heads and fish fish parasites. Bacterial diseases can be sprinkled with 1 g / m3 of bleach, and parasitic diseases can be sprinkled with 0.3 g / m3 of trichlorfon.

Fourth, daily management should be put in place to regularly apply quicklime to improve the pH value and hardness of the water area, increase calcium salt, promote the material circulation in the water area, and improve the water quality, which is conducive to the growth of fish and inhibit the occurrence of fish diseases. Generally, 15 kilograms of quicklime is applied per mu, once a month. Before stocking, use combined fishing gear to remove wild fish or drugs to kill wild miscellaneous fish.

During the breeding period, purse seine and trawl should be used to trap wild miscellaneous fish regularly to improve the survival rate of fish species. Fertilization and intensive cultivation of small reservoirs should have oxygen-increasing equipment, transportation equipment, drainage and irrigation equipment, anti-escape facilities and fishing nets. In addition, the reservoir should have special personnel on duty, pay attention to flood control, irrigation and other conditions, often check fish interception facilities, timely salvage floating objects, ensure smooth drainage and prevent fish flight. Always observe the water quality and check the growth status of fish in order to apply fertilizer reasonably.

With the continuous development of China's aquaculture industry, fish culture is a relatively good development in China, but farmers should not blindly follow the trend, before breeding should first understand the market situation and demand, so as not to blindly cause unnecessary losses.