Matters needing attention in early spring fish culture to grasp the initiative of fishery production

Fish culture

To do a good job in the early spring management of fish ponds, farmers can effectively grasp the initiative of fishery production throughout the year, so as to reduce the cost of fish culture and improve the economic benefits of fish culture. We especially for the majority of aquaculture farmers to summarize the five major points for attention in early spring fish culture.

1. Topdressing

In early spring, when the water temperature of the pond was stable at 8 ℃-10 ℃, fertilizer was applied to cultivate natural bait in the water. The amount of fertilization should be determined according to the fat and thin water quality and the quality of fertilizer, generally 60-90 kg of human feces and urine, or 100-150 kg of animal manure. If chemical fertilizer is used, the ratio of nitrogen, phosphorus and potassium is 1 ∶ 1 ∶ 0.5. the total dosage per mu is 3-7 kg, with an interval of 5-10 days, so that the water quality can be kept yellowish brown or yellowish green, and the transparency is about 30 cm.

Second, bait

When the water temperature rises to 10 ℃, the fish begin to eat a small amount. If it is found that there are many small areas of turbidity from the bottom of the pond to the surface of the water, it shows that the fish are in a state of hunger and fish activities are frequent. Early spring fish culture bait should be based on bean cake, wheat bran, cornmeal and other concentrate feed, fixed point every day, regular feeding, each feeding should be 1.5% of the fish body weight of 3%. After that, with the increase of water temperature, the number of bait is gradually increased, and it is changed to be fed twice a day. The specific amount of bait should also be flexibly controlled according to the water temperature, weather and the feeding situation of fish. At the same time, food introduction and domestication should be carried out until it can be fed at a fixed point on the table, which can improve the utilization efficiency of feed.

Third, water injection

In early spring, due to low water temperature, small fish, less active food intake, the pool water should not be too deep, should be controlled at 0.6-0.8 meters. With the increase of water temperature, the fish body increases and gradually deepens the water level. In early spring, it is best to change the water once, and replace it with 1 per cent of the water in the whole pool. After that, water will be injected every 15 days, raising the water level by 10-15 cm each time, keeping the pond water level about 1 meter from March to April, and preventing the inflow of sewage and enemy organisms at the same time. In case of continuous overcast and rainy weather, the water depth of the pool should be increased appropriately to prevent the temperature of the pool water from changing too much. If the water quality of the pool is found to be aging, 0.2 meters of fresh water can be injected into the pool and sprinkled throughout the pool with 20-30 kg of raw calcareous water per mu of water.

IV. Disease prevention

Long-term starvation of fish will lead to stagnation of growth, decline of physique and increase of diseases. In order to prevent the spread of pathogens, well water or clean river water should be selected as far as possible when injecting water into fish ponds in early spring. The pond should be managed by special personnel, patrol the pond every morning and evening, check the water quality, and determine the amount of fertilization and bait. Salvage the residual bait in time, keep the pool water clean, and forbid feeding spoiled feed. The common fish diseases in adult ponds in spring are water mildew, vertical scale disease and ascites disease. Salt and baking soda mixture can be used to treat the disease by sprinkling the whole pond or washing the fish. Sprinkle 1 mg / L bleach and 0.7 mg / L copper sulfate solution alternately in the whole pool every 15 days. If fish disease is found, it should be diagnosed and treated in time. After starting to feed, fish can be fed with some baits to improve their disease resistance.