The size of crab species affects the efficiency of crab cultivation. In recent years, the demand for pollution-free large-size crab species has increased. Now the pollution-free crab cultivation techniques are described below for reference by farmers. 1. Requirements and Construction of Paddy Fields Paddy fields require a quiet environment, convenient transportation, energy irrigation and drainage, water conservation and fertility, soil quality of loam, and water sources free from industrial wastewater, chemical fertilizers, and pesticides. The field project consists of Weigou, Tiangou, and crab seedling holding pools, accounting for more than 25% of the total rice field area. According to the needs of rice and crab symbiosis, a width of 3 meters wide and a width of 1 meter and a depth of 0.8 meters will be excavated at 1.5 to 2 meters away from the field. In the field, a crab ditch is excavated every 4 meters, so that the paddy field is in the shape of a “field†shaped piece. The ditch is 1 meter wide and 0.6 meters deep, and communicates with the ditch. On the south side of the field, a 20-meter square crab holding pool with a depth of 80 cm is built for every 667 m2 of paddy field, and it is used as a holding pond for intensive cultivation of large-eyed larvae or harvested crabs. The excavated earthwork was used to reinforce the field ridges, and plastic fences, No. 5 iron wires and stakes were used to build the fences and escape protection facilities on the fields. Paddy field water inlets and outlets also use mesh to prevent escape. After finishing the plots, 7.5 to 10 kg of lime water was used per 667 square meters. The whole field was splashed to kill the disease. At the same time, 0.5 kg of tea pods were soaked in warm water for a day and night to splash rice in order to kill wild fish. Immediately after the toxicity disappears, weeds such as black algae and water peanuts are transplanted in pools and trenches, covering an area of ​​50% to 60%. 3. Cultivation and management of crab species Cultivation of non-pollution crab species in paddy fields In order to obtain a good harvest, crab quality is the key to good or bad quality. The production practice has proved that it is best to choose a pure Chinese mitten crab crab seedling that is robust, crawling, and tidy, with a specification of 150,000/kg. The crab raising pond was sterilized with 5kg of lime every 20 square meters in mid-April, and 12.5kg of cooked cow dung was used in late April. Paced bait was bred and water was injected immediately for 30cm. In early May, 0.5kg of crab seedling was released. (1) Holding pool cultivation stage. After the crabs enter the pond, they are supplemented with eggs and roach at a ratio of 1:3 to 5 depending on the amount of natural food. They are fed 5 to 8 times a day and the bait rate is 200%. When the crab grows to stage II, it uses minced fish, bean cake paste and bran, and feeds it at a ratio of 2:1. It feeds 3 to 5 times a day and the feed rate is 100%. With the growth of crab seedlings. Gradually increase the amount of feeding. After 15 days, artificial feed can be fed, formula: fish meal 25%, bean cake powder 25%, vegetable cake powder 23%, wheat flour 20%, bone meal 3%, yeast powder 2%, mineral additives 2%, another 0.1% added Chitin and 0.1% of complex vitamins are rolled into pelleted feeds containing 40% crude protein. Every day, 20 to 3 kilograms of feeding tanks are fed in a holding pool of 20 square meters, which is fed in the morning and evening. Crabs were cultivated until early June, and the earthworms in the holding ponds and rice fields were dug out. Water was poured from the inlets and the crabs followed the water flow into the rice fields. (2) Paddy field cultivation stage. One month after the arrival of the crab seedlings into the field, the daily feeding of compound feed was calculated as 20% to 25% of the crab's body weight, and it was 1/3 at 8 am and 2/3 at 18 o'clock. From the beginning of August to the middle of September, it is the growth control stage of crab species. Normally, it is fed once every night at 6 o'clock in the evening. In the first 20 days, the daily input of the batch material accounts for about 7% of the body weight, and the green grass accounts for 50% of the body weight. At 3% of body weight, grass accounts for 30% of body weight. After mid-September, it was the growth and maintenance phase of crab species, all of which were converted into plant feeds, such as raw pumpkin and cooked hawthorn, which accounted for 10% of the body weight. Every time before the arrival of the oyster shell, increase the feeding amount of animal feed (more than 50%), found that the crab began to shell, can be poured 3 to 5 kg of lime, and put a proper amount of water peanuts to increase the attachment of crab oyster shell During the oyster shell will not change the water. Increase the number of food tables and feed them in small quantities. Every 15 to 20 days in the paddy field, 5 to 7.5 kilograms of quicklime is poured on every 667 square meters to kill the disease and supplement the calcium that the crab needs. Persist in the inspection field one or two times a day, check whether there is leftover bait, water quality changes, and anti-escape facilities and the presence of predators, etc. to determine the amount of feed, change the amount of water and take appropriate measures to prevent disease. The prevention of crab disease is mainly based on prevention. From July to October, a total of 500 grams of fibrin insect nets are sprayed once a day to prevent ciliate disease and black shank disease; adhere to oxytetracycline and bait to prevent bacterial diseases, and the dosage is 50 grams. 100 grams of bait were fed for 3 days per month; plants were washed before entering the field, and 25 grams of strong chlorine was sprayed and disinfected per cubic meter to eradicate predators. 4. The catching of crab species and the habit of overwintering crab species can be captured by running water method. That is, when the paddy fields are released, net cages are used for trapping at the outlet. Or catch along the edge manually, and the remaining amount is captured after the field water is dried. The average catch rate can reach 95% or more. After the crabs are caught, they will be separated according to the size and size, and will be managed through winter. The method is to select the river or pond with better conditions, put the young crabs into crab cages or cages, submerge into the water, feed them regularly, and strengthen feeding and management. Strictly waterproof surface, and then put into paddy fields, ponds or large water surface for crab breeding from March to April of the following year. You can also choose a crab pool with good conditions, direct wintering of crab species, strengthen winter management, make it safe for winter, and strive to eat and grow earlier in the following year. If crab species need to be sold, they are usually raised in cages or crab cages. Get up and go for the price. Unviersal Adhesive Bandage,Universal Water Repellent Plaster,Strong Adhesion Adhesive Bandage,Cotton Plaster RFX+CARE Manufacturing Co.,Ltd. , https://www.rk-rfxcare.com
2. Cultivation and Management of Rice Rice varieties with high fertility, hard straw, and not easy lodging, strong disease resistance are selected. 15 days before transplanting, paddy fields were planted, 500 to 750 kilograms of fertilized farmyard fertilizer, 20 to 25 kilograms of long-acting urea, and 35 to 40 kilograms of superphosphate per 667 square meters were used as base fertilizers. 2 to 3 days before transplanting, the seedlings are given a high-efficiency pesticide to prevent the spread and spread of rice diseases and insect pests; transplanted seedlings are required to be robust and disease-free. Usually transplanted in shallow water, wide and dense plants, row spacing 30 to 35 cm, plant spacing 12-13 cm planted. Appropriately increase the planting density in the inside of the larvae and near the crab ditch, and exert the marginal advantage to increase rice yield.
(3) Water quality management. The holding pool is filled with water every 4 to 5 days, each time filling with water 10 to 20 cm until the water depth is 60 to 80 cm. Change the water by 1/3 a day in hot weather. During the incubation period, the crabs insisted on starting daily oxygenation. After the third and the fifth stage crabs enter the field, try to raise the water level in the paddy field and change the water every 3 to 5 days. Change the water once a day at 10:00 in the summer and change the water volume to 1/3-1/2 of the field water. The water level is raised to about 50 cm, and the water level or dehydration and baking fields are not arbitrarily changed so as to facilitate the growth of normal molting. In addition, the water temperature difference can not be greater than 3 °C.
Non-pollution High-quality Crab Breeding Rice Field Cultivation Techniques