The white field sets up crabs. It can make full use of the ecological environment and biological resources in the white field and make the white crabs and river crabs take their own needs. This will greatly increase economic efficiency. In general, 800-1000kg can be produced per 667 square meters, and 50-60kg can be harvested. The relevant technologies are introduced as follows: I. Selection and preparation of Ling Baitian Choose a land with sufficient water source, good water quality, non-toxic, non-fouling and convenient irrigation and drainage, with an area of ​​2,000-3,500 square meters, suitable for water retention performance. Good sandy loam or clay is preferred. In the white field, crab trenches are excavated. The ditch is 1.5-2m wide, and the ditch depth is 1-1.2m. The ditch is connected to the ditch in a “field†shape. Digging mud raises and widens the surrounding fields. Blocks around the block are built with calcium-plastic plates, asbestos tiles or other materials to prevent escape. The walls are 0.5-0.6m high, buried 0.1m in the soil, and slightly tilted toward the inside of the field. The inside of the field must be smooth and free of support. The corner of the escape prevention wall is rounded. The inlet and outlet ports shall be sealed with polyethylene mesh, and a bamboo fence shall be built on the outside. The mesh shall be covered to prevent the crab from escaping from the inlet and outlet. Second, the planting of Ling Bai 1. Apply base fertilizer. Before planting eucalyptus, the plots shall be ploughed, exposed to sunlight, and soaked in water. Then, 500-800 kg of organic fertilizer, such as composted pigs and cow dung, and 40 kg of superphosphate are used as basal fertilizer (uniformly applied to the surface of the soil) per 667 square meters. 2. Select white varieties. There are many white plague varieties, and good varieties with high yield, strong resistance and early maturity should be selected according to local conditions and suitable for planting in deep paddy fields. 3. White transplant. Transplanting is generally required in the middle of April. The row spacing between white and white is 1m, the plant spacing is 0.6m, and 1000-1200 plants are transplanted per 667m2. Third, the proper cultivation of aquatic fishermen are: "crab size, see plants, crabs, see plants." This shows the importance of aquatic grasses for raising crabs. At present, most plants are planted with hardgrass. For every area of ​​667 square meters, 30-50g of Vallisneria seeds are used. The method of cultivation of Vallisneria seedlings is similar to that of rice mulching. When the grass grows to about 10cm, it is planted in the field using the rice “casting method†and the crabs can be placed until they reach a length of about 30cm. Four, juvenile crabs in stocking quail live after the transplanting crabs can be stocked, juvenile crabs stocking specifications to 40-60 / kg is good, stocking 20-30kg per 667 square meters, can also be stocking specifications 100-200 only /kg, stocking 10-15kg per 667m2. The stocking young crabs require uniform body color, neat specifications, robust physique, and no disease or injury. In addition, in order to allow the crabs to freely feed on the abundant bait after being thrown into the field, 150-200kg of freshly treated snails that have been sterilized are placed every 667 square meters before and after Ching Ming. Tiangou added some araceae, duckweed and so on. Fifth, field management 1. Feed the bait. Feeding or restocking should be done with "four settings" (fixed, regular, quantitative, qualitative). In May-June, the young snails that lived with live snails before and after Ching Ming were the main species; from July to September, in addition to feeding plant foods such as pumpkins, wheat, soybeans, etc., small fish, shrimp, and pig blood were supplemented in a timely manner. Silkworms, snails, oysters and other animal foods to meet the nutritional needs of crab growth. 2. Water quality regulation. The growth and development of crabs requires very strict water quality. Therefore, attention must be paid to observing changes in water quality and weather changes at any time, and timely regulating water quality and water levels. Usually, the water depth should be 0.2-0.3m and the water depth in the ditch should be 1m. In the hot season, it is necessary to insist on changing the water frequently. In general, change the water once every 2-3 days, change the water 0.2m or so each time, keep the water quality fat but not greasy, live without light. When changing the water, avoid using a piece of water to fill the fields. 3. Adhere to daily field inspections. Pay attention to preventing escape, leaking, poisoning and preventing snakes and rats from harm. 4. The prevention and control of diseases and insect pests in crab cultivated Baitian. White crabs in the field can reduce the occurrence of pests and diseases, and generally do not require the use of pesticides. Even if pests and diseases occur, biological control should be used as far as possible, with no or little use of pesticides. It is strictly prohibited to use pesticides such as buprofezin, methamidophos, omethoate, 1605, carbofuran, pyrethroids, and imidacloprid. The application must be done after sunny dew. Change the high-concentration spray to a low-concentration spray and use a nozzle with a 0.7mm hole diameter. At the same time, the drug should be sprayed as far as possible on the upper middle of the plant to reduce the liquid falling into the water. In case of improper application of pesticides, pesticide concentration is too high, should be quickly filled with "Happy Valley" to ease the phytotoxicity. Six, pick crabs generally start crabbing in the middle and late September. The methods of catching include catching crabs in the water, catching them by hand in the night, and trapping them. After the crabs are caught, they must be sold in time.