How to use rice fields to cultivate crabs efficiently?

Raising crab in rice field is a kind of fishery-agricultural comprehensive production mode with high benefit. The dense clumps of rice plants not only form a hidden molting place for crabs, but also an excellent living environment. Not only can young crabs be released, young crabs can be cultivated into crabs, but also adult crabs can be raised. In 1996, crabs cultivated in rice fields in Shuyang County, Jiangsu Province, reached the production level of 500kg of rice per mu and 30kg of crabs per mu, with an income of about 5000 yuan per mu, 2-4 times that of conventional rice.

Preparation of rice fields for raising crabs

Crab rice fields need escape prevention facilities. The ridge of the field is required to be 60 cm high and 40-50 cm wide, with double-layer plastic film on the ridge. It can also be surrounded by smooth asbestos tiles or polyethylene mesh around the rice field. Anti-escape sheds should also be installed at the water inlet and outlet. The ring trench is excavated 3 meters away from the ridge of the field, and the ring trench of raising crab seedlings and crab species is 1 meter wide and 0.8 meters deep. The crab ring groove is 2-3 meters wide and 1 meter deep. Ditches and slips should also be opened in the middle of the fields (crab ponds). The ditch is 50-60 cm wide and 50 cm deep, and the cultivated crab can be widened to 1 meter and 60 cm deep. It covers an area of 8-10 square meters and is 1 meter deep. Ditches and slips account for about 30% of the total area of rice fields. It is appropriate to take 2-3 mu as a culture unit in the crab field.

Seedling stocking

Crab breed 0.5 kg per mu of crab fry. Cultured adult crabs can breed 1500-2000 crabs with an individual weight of 10-15 grams per mu. Can also use the early propagation of crab seedlings, put in the greenhouse to strengthen cultivation, and then put into the rice field in May, can shorten the breeding cycle.

Feeding and management of crabs

Feed 1-2 times a day, usually 8-9 am and 4-5 pm. In particular, adult crabs are mainly fed in the evening, with a daily feeding rate of 3% and 5%. Feeding points should be on pre-set tables or on the banks on both sides of the crab ditch. When throwing and feeding, we should pay attention to check whether there are loopholes in the ridge of the field, because the river crab has the habit of drilling holes, and plug the loopholes in time when they are found. Pay attention to flood prevention, crab escape during heavy rain, and water shortage in dry season. Under normal circumstances, the water depth of the paddy field is maintained at 6-10 cm. In order to keep the water fresh, the water should be changed frequently, once a week from June to July, 2-3 times a week from August to September, and every 5-10 days after September. For each change of water, 1 beat 3-1 stroke 5. In addition, quicklime was applied in ditches and slips every 10 days during the feeding period, so that the water was 5-10 mg / L.