Yixing City currently has 2,400 acres of shrimp and crabs in paddy fields. In 1998, the 30-acre technical pilot project was carried out on the basis of the new town. After more than 6 months of meticulous management, it was sampled and accepted in pilot fields in early November. , economic benefits and aquaculture technology have reached the desired goals, and have accumulated a certain amount of experience in breeding.
In the breeding process, in order to improve the survival rate of crabs, a secondary stocking management measure was adopted.
1 First-stage holdings Around April 15th, the 4-7-year-old juveniles cultivated in greenhouses were put into special pools for intensive cultivation, and 800 were placed in a mu and the water depth was 60 cm. Put 100 kg of lime per acre into the water before putting it into the water. After the drug disappears, place the juvenile crab. The water depth is about 60 centimeters. The water inlet is equipped with a shed net with a 40-mesh sieve to filter it. Crabs inhabit subtle attachments. Peanuts or willow roots are plunged into small pools. The water quality remains fresh and the transparency is about 40 cm. Sprinkle 1ppm lime water once every 10 days or so, feed mainly on small trash, and feed once or twice a semester, feed fresh water and grass at the same time for 5 hours, feed until about June 10, and plant it. After the live tree is put into the ditch of the rice field.
2 secondary culture
2.1 Preparation of Paddy Fields Fertilizers for the application of ammonium bicarbonate 100 kg/mu, compound fertilizer 20 kg/mu in paddy fields, and sheep and pig manure as piles are used as organic fertilizers for paddy fields, and 1000 kg/mu for each acre. , And then open the ditch, the excavation of the ditch was field-shaped or well-shaped, the excavated soil is used to increase the height of the ridge, 3 meters wide and 1-1.2 meters deep, and the ditch accounts for 20% of the total area of ​​the paddy field. Anti-escape facilities use calcium-plastic plates, which are buried along the crab-raising paddy fields and are buried 20 centimeters in the soil, 50-60 centimeters above the surface of the mound. Into the drainage system, one end of the pool into the water, the inlet with a 40-mesh sieve filter, the other end of the drainage, drain port installed grid, so that the water into the drainage convenient, can control the water level, safe and reliable. Before the stocking, 100ppm of the quicklime was used to clean the ditch to eliminate the enemies, and after the disappearance of the medicinal property, it was appropriate to plant leaves of the black-green algae or Malayianzizi in the ditch, and the number was appropriate to cover 3/4 of the ditch. Provide shrimp and crabs with good habitats and clam shells and increase plant foods.
2.2 Seed rearing will raise the young crabs in the pond to 600 rice fields per acre, and hold the eggs 0.25 kg per acre.
2.3 Rice cultivation and management Rice variety selection 9520, seedlings were first transplanted into Daejeon after culturing large seedlings in sorghum. Three times before transplanting, a high-efficiency pesticide was applied to the seedlings. The row spacing is 56 and the marginal advantages of the inner side of the field ridge and the two sides of the rill field are utilized to reasonably increase the planting density of the seedlings. Weeding and controlling pests use high-efficiency, low-toxicity pesticides and insecticides. Double-dose 0.25 kg/mu. When spraying rice to 30%, use spray to treat once. The short-term precipitation of the paddy field is used for a short period of time. The water level can be lowered to the surface of the paddy field, so that the air can enter the soil and the sunlight can shine on the ground to increase the temperature of the rice. The purpose can be.
2.4 Breeding and management During the whole cultivation period, animal feed (small miscellaneous fish, quail meat, etc.) accounted for 47%, concentrate feed (bean cake, wheat, etc.) accounted for 34%, green feed accounted for 18%, daily feeding amount was reasonable with shrimp, crab 5-10% of body weight is controlled flexibly, feeding twice a day, according to the weather, changes in water quality to eat, adjust the amount of feeding, feeding time 8:00, the amount of bait accounted for 1/3 of the total, afternoon 6 When it is 2/3, the bait requires fresh, palatable, nutritious, and spoilage foods do not have to be used. Regulation of water quality In June, we will change the water once a week, change the amount of water by 1/4, change the water once in 2-3 days from July to August, and change the water by 1/3 each time. It is advisable to change the water once every two hours or so. When the water is changed, the water level is relatively stable. During the breeding period, every 10 days, 10 ppm of quicklime was poured into the whole ditch, and a certain amount of locust and 6 grams of oxytetracycline per kilogram of bait were added to the feed. Day-to-day management: Inspect the ponds daily to see if there are signs of crab escape.
2.5 The cages are used for fishing, and they are drained from the paddy fields and collected directly to the market, with a rate of 56%.
2.6 Harvesting and Benefits The average yield per mu rice is 420 kilograms, shrimp is 12 kilograms, specifications are more than 3 centimeters and up to 80%, 4 centimeters or more are up to 20%. 40 kg of crabs, up to 25% for size 2.5, 2.5 for more than 25%, 35% for more than 3, 45% for 4 or more, benefit: 600 RMB for 50 RMB per kg of shrimp, 120 RMB for each kg of crab 4800 yuan, 1.4 yuan per kilogram of rice, a total of 574 yuan, the total output value of 5974 yuan, cost: crab, shrimp 610 yuan, 120 yuan of fencing facilities, 710 yuan of chemical fertilizers, pumps, electricity 50 yuan, 80 yuan on the delivery, pesticides 5 Yuan, feed 500 yuan to 2075 yuan, profit of 3959 yuan, to achieve the desired benefits.
2.7 Experience
1 The survival rate of juvenile crabs in paddy field crabs is high. Because of the small water environment of the paddy fields and high water temperature, the stocking crabs are sexually mature in parts from July to August, and the survival rate is quite low.
2 Maintain clean water and adequate dissolved oxygen in the rice trench. When the water level is too light or the water quality is too strong, add new water or change water in time. Otherwise, it will affect the clam shell of the crab.
The three sets of shrimps make full use of the water environment, and part of the shrimp can be used as food for crabs, which is beneficial to the growth of crabs.
Rice field shrimp and crab polyculture industry is an emerging system-rich project with higher comprehensive economic benefits in current agricultural production.