Freshwater crayfish, also known as Procambarus clarkii, is favored by consumers because of its tender meat and rich nutrition. Rice-field shrimp farming is a kind of virtuous cycle of ecological farming mode. Generally, the output per mu is 400-500 kg, and the high-yield yarn is 00 kg. Rice field shrimp can eat weeds, aquatic organisms, mosquitoes and flies. At the same time, the activities of shrimp in rice fields not only increase the amount of dissolved oxygen in the field, but also have the effect of keeping fertilizer and increasing fertilizer.
First, the selection and arrangement of rice fields.
The freshwater lobsters in the paddy fields must be adequately sourced with water, free from the effects of drought and floods, fresh water, fertile soil, good water retention, and sunny rice fields.
1. Reinforce the height of the field. To increase the height of the field ridge, the field ridge should be 0.5 meters in height and 0.5 meters in width. It should be strong and strong to prevent heavy rain from collapsing or leaking.
2. Dig good shrimp ditch and shrimp slip. Shrimp ditch can be divided into ring ditch and field ditch. The ring ditch is the main place for raising shrimp, and can be excavated along the inside of the field 2-4 meters, with a width of 1 to 2 meters and a depth of 0.8 to 1 meter. The field ditch, also known as the ditch, is mainly used for shrimp seedlings to enter the rice fields for food covert use, and depending on the size of the field block, several horizontal ditch excavations in the field are connected with the ring ditch. Dig the shrimp at the intersection (1 to 1.2 meters deep, with an area of ​​about 3 to 8 square meters). The area of ​​shrimp ditch and shrimp slips generally accounts for 15% to 20% of the total rice paddy area.
3. Build inlets and outlets and install shrimp facilities. In general, the water for shrimp farming should be separated from the farmland water, and separate water intake channels should be constructed. The water inlet and outlet were built on the opposite corners of the paddy field and a strainer was installed to prevent the shrimps from fleeing. The filter is generally suitable for 6~8 mesh, the filter should be 20~30 centimeters higher than the field, the bottom part should be deeply buried in the base soil, the length of the influx filter should be 2~3 meters, and it should be installed into the rice field in arc. Prevent wild fish from mixing in.
Second, shrimp stocking specifications, density and time.
1. Stocking specifications. In order to increase the survival rate of lobster, 3~3.5 cm large-scale shrimp must be stocked.
2. Restocking time. Regardless of whether it was shrimp or egg-bearing broodstock, we rushed to fight for an “early†word. Usually in November of each year or the end of March of the coming year.
3. Stocking density. When stocking in November or March, 30 to 40 kg per mu of paddy fields are stocked and broodstocked. The juvenile shrimp species will be stocked from April to May in the following year, and will be released from 1.2 to 15,000 rice fields per mu. Note that brooding broodstock should be fed directly into the outer furrows for wintering, and when the larvae return to green, they will be induced into the paddy fields.
There are two general breeding and holding aquaculture modes: 1 Summer stocking is mainly juvenile shrimp that was artificially propagated in the year of stocking, and the time is from July to September. Per-mu shrimp rearing range from 1.5 to 20,000 juvenile shrimp. 2 Winter stocking is usually conducted in December, and about 1 to 15,000 shrimp species are stocked with about 3 cm per mu of shrimp ditch. There are conditions where two seasons of shrimp farming can be conducted, from July to October, one season of freshwater shrimp, and from December to the fifth year of the following year, one season of freshwater lobster.
Third, field management.
1. Change water regularly. Adhere to regular water changes, so that the water quality of the shrimp ditch to keep fresh, especially in the summer and hot season, it is necessary to constantly change the water. Keep the water level in the shrimp ditch stable even when it is in the field.
2. Feed the feed. Juveniles start feeding immediately after stocking and can be fed with bran, bean cake or fish (shrimp) with pelleted food. Feed 2 times a day, mainly feeding in the evening, the daily feeding amount can be 2% to 4% of shrimp weight. According to the season, the weather, and the situation of feeding and eating shrimp, reasonable adjustments.
3. Deal with the contradiction between fertilization and shrimp farming. Use high-efficiency and low-toxicity pesticides as much as possible, and strictly control the amount of safety. There are the following methods for spreading drugs: 1Dry water method. Dry the water before spreading the medicine, and let the shrimp sprouts be caught in the shrimp gully and then spread it. Sprinkle the drug on rice leaves, and after the toxicity of the drug disappears, inject fresh water into the field. 2 Deep water sprinkler method. First deepen the water, and then do so. 3 drug dipping method. Transplanting seedlings first put the roots of the seedlings in the liquid soaking for a period of time before transplanting the seedlings. This method has special effects on the treatment of grasshoppers.
Fourth, disease prevention and harm.
1. Strictly control the quality of shrimp, buy a healthy, non-infected shrimp. 2. Do a good job in water quality management. Regularly use quicklime to increase alkalinity and improve water quality. 3. Use high quality food. 4. Capture rats, water snakes, etc. in time, and prohibit ducks from entering rice fields.
Fifth, arrest.
Around October, when the minimum temperature drops to 18°C, shrimp should be caught in time. If rice is not mature yet, it can be used for catching water and catching water. Usually, it is selected to discharge water during the morning and a good net is used. Most of the shrimp naturally enter the net with water. After the water is drained and flushed with water several times, all the shrimp can be caught.
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