Shrimp rice farming should be selected from sufficient water sources, easy drainage and irrigation, water retention capacity, dry, not drought, floods do not flood, and good ecological environment, no sources of pollution around the fertile soil, the substrate of the natural structure of the paddy field. Generally, low lake fields, cold soaked fields, and winter soaked fields are more suitable. There is no limit to the size of the area, but if it is too small, it is not cost-effective, and it is best to take 50 acres - 100 acres as a farming unit. For larger scale, higher yield and efficiency requirements of the base, but also consider the convenience of transportation, power supply is guaranteed.
2, the environment
Including ring ditch, field ditch excavation, ridge widening, heightening, reinforcing, water quality, water level control, water planting.
(1) ditch digging: along the paddy field ridges around the inside of the circular ditch dug shrimp, ditch width of 2 meters depth of 1 meter, ring shrimp ditch 2 meters away from the ridge, the corners of the best arc. A unit of 100 acres, but also in the middle of the field to excavate "ten" or "a" field ditch, field ditch width 0.5 to 1 meter, 0.5 meters deep. Ring ditch and field ditch area accounted for 5% to 10% of the paddy area.
(2) Ridge building. Use the soil from digging the ditch to widen, heighten and strengthen the peripheral ridge, the top surface of the ridge is 2--3 meters wide and at least 0.8 meters above the field surface, and the ridge should be compacted to prevent water seepage or collapse.
(3) Planting grass. Planting water plants can provide quality bait for crayfish, but also for its habitat, moulting growth to provide a good environment, is one of the key measures for the success of crayfish farming. Water plants are submerged plants, can also plant water hyacinth and water peanuts.
(4) control water quality and water level. Water quality should meet the requirements of healthy aquaculture, freshwater crayfish are very sensitive to heavy metals, certain pesticides such as trichlorfon, bowie ester insecticides, should be noted. Water level should generally be maintained above the field surface 30 - 60 cm; fall and winter, the temperature drops rapidly, it is desirable to raise the water level to keep warm; spring temperature rises faster, and the sun irradiation is strong, it should be lowered to enhance the water temperature; summer temperatures are too high, the water level should be deeper in order to achieve the purpose of appropriate cooling.
3, in addition to pests
Shrimp rice rice paddy threat to the survival of crayfish more hostile, water centipede, frogs, water snakes, eels, loaches, carnivorous fish (such as catfish, loaches, fish), water rats, etc. are crayfish's natural enemies. Therefore, crayfish stocked with drugs (such as quicklime) before the complete removal of the above enemies, must not be sloppy. Water inlet to be 20 - 40 mesh screen filter, the drainage outlet should also be surrounded by a dense net to prevent the invasion of pests. Normally, we should inspect diligently and remove the pests in the field in time. Conditions can be set in the field edge of some scarecrow, colorful cloth, intimidation, drive away waterfowl.
4, put seed
Insist on early release, put enough, pay attention to quality. Implementation of shrimp rice rice paddy should be put in September-October juvenile shrimp or July-August put shrimp (can be set up near the paddy shrimp temporary pool, preferably with shrimp paddy connected to the rice paddy, to be harvested in a timely manner after the rice irrigation shrimp into the paddy). Put the amount of: September - October each year in the rice harvest, to the irrigation of the rice paddy per mu put more than 1cm crayfish larvae 1-2 million tails, or 7 - August each year, in the rice harvest to the rice paddy circular ditch or near the temporary pool put shrimp, per mu of rice paddy put 30 - 40 pounds (preferably in the sunny mornings and evenings), the earlier the time to put, the better the results of breeding. In order to ensure the survival rate, the best shrimp directly from the breeding ponds or natural waters near the fishing, away from the water time is generally not more than 2 hours; to adhere to the quality standards of selection, try to select the appendages complete, robust, disease-free, injury-free, smooth carapace, no attachments, and strong activity and individual weight of more than 30 grams of male and female shrimp as the release of the shrimp, male and female ratio control in the 2-3 : 1. According to the above put in the amount. The implementation of scientific management, each mu of rice paddy can produce 200-300 pounds of commercial shrimp, mu increased net profit of 600 to 1000 yuan.
5, anti-escape
Crayfish benthic crawling and against the water on the strong ability to learn, so pay attention to escape. Shrimp paddy rice paddy inlet and outlet to set up anti-escape facilities, water inlet with 20 to 40 mesh filtering water inlet, outlet should also be surrounded by a dense mesh to prevent freshwater crayfish escape by water flow; paddy paddy paddy around the ridge with a 70-centimeter-wide dense mesh or asbestos tiles around the block, the lower end of the mesh is buried into the soil 20 centimeters, the soil on the part of the 90-degree tilt inward. Use asbestos tiles to do escape wall is more economical, the cost of 2.5 yuan per meter, you can manage 3 to 5 years, the effect is also better. Normally, we should always check the inlet and outlet and closed mesh or asbestos tiles with or without loopholes (rats can bite through the mesh), to prevent the escape of shrimp.
6, feeding
Appropriate baiting and fertilization is an important measure to improve the breeding yield. Lobster miscellaneous diet, commonly used feeds are snails, clams, wild fish and shrimp, livestock scraps, water, land grasses, vegetables, corn, grains, rice bran, wheat bran, soybean dregs, cakes. Farming should be based on watercress, farmyard manure with appropriate dregs, rice bran, wheat bran, cakes and other agricultural by-products and crayfish special feed. Feeding to do "four", that is, "time, point, quality, quantity. Specifically, the early appropriate to animal feed-based, medium-term to watercress, farmyard manure and agricultural by-products feed-based, late to agricultural by-products feed and artificial feed-based. Insist on 1 to 2 times a day, evening and night feeding, daily feeding control in the stock of shrimp between 1% to 3% of the total (to the day feeding bait in 3-4 hours to eat up). Where possible, more snails and clams can be put in.
7, disease prevention
Using shrimp and rice cropping mode crayfish less morbidity, it is found that there are mainly two diseases to the loss of crayfish farming.
1, virus disease. Caused by viruses, manifested by the disease shrimp chelipeds weakness, anatomically visible hepatopancreas enlarged, darkened; empty stomach, intestinal congestion, color segmentation phenomenon. Prevention and control methods (1) with 0.3 ~ 0.5mg / L povidone iodine or tetraalkyl quaternary ammonium complex iodine splashing the whole field for two consecutive times, each time the interval of 1 ~ 2 days; (2) per acre with 100 ~ 150 grams of chlorine dioxide into the water splashing. Adding yeast immunopolysaccharide to the feed can play a preventive role.
2, ciliopathy. Caused by ciliate attachment, manifested in adult shrimp, young shrimp, larvae and fertilized eggs on the body surface, appendages, gills and other parts of the formation of a thick layer of "hair". Prevention and control methods (1) 0.3 ~ 0.5mg / L tetraalkyl quaternary ammonium complex iodine splashing the whole field; (2) according to the instructions of the use of ciliate net or zinc sulfate. In addition, feeding special artificial feed for the moulting of crayfish can promote the moulting of crayfish, so that they can shed the old shells with ciliates.
8, fishing
Long-term fishing, catching big to stay small is a very important measure to reduce costs and increase production. Starting in early April each year, we must use the shrimp cage, cage net will reach commercial specifications of crayfish fishing on the market one after another (not up to specifications continue to stay in the rice paddy farming), so that both the large size of the crayfish in time to catch up to sell at a good price, reduce the death of losses, but also reduce the density of crayfish in the rice paddy to promote the rapid growth of small-size lobster to improve the yield benefits. Fishing method: the shrimp cage and cage net (mesh specification of 2 cm or so) placed in the paddy shrimp ditch or paddy fields, early every morning to collect shrimp, shrimp cage and cage every once in a while to move the position, in order to facilitate the capture of shrimp, conditions can be set up in the cage bait to lure the crayfish into the net. the end of May can be in the middle of rice rice transplanting before the whole field at night before drying the field to capture.