Crab culture in paddy field is a new three-dimensional culture mode developed on the basis of fish culture in paddy field. Rice crabs are born where they belong. Raising crabs in paddy fields has little effect on rice yield per unit area, and it can produce 20-30 kilograms of crabs per mu, which is more than 1000 yuan higher than that in ordinary paddy fields. The main technical points are as follows: First, choose good fields, with convenient water sources, good water quality, absolutely no pollution, good soil water retention and concentrated contiguous areas; The second is to do a good job in field engineering, mainly the ditch pond for raising crabs in rice fields, which consists of three parts: ring ditch, field ditch and temporary pond. Huangou is the main place for raising crabs. Dig a trench of 2-3m inside the embankment around the site, with a trench width of about 1 .5m, a trench depth of1m and a slope ratio of 1:2 to form a ring. The ditch is mainly used for river crabs to crawl into the rice fields for food and hiding. Every 20-30m, a transverse ditch or a transverse ditch with a width of 50cm and a depth of 60cm is opened, and the slope ratio is 1: 1.5, which is communicated with the ring ditch. The temporary breeding pond is mainly used to cultivate young crabs, temporarily raise crab species and harvest commercial crabs. They are usually excavated in a corner or side of the field. The pond is 5-10m long, 2-3m wide and1.2-1.5m deep. The water surface of ring ditch, field ditch and lintang accounts for about 20% of the rice field area. Crab ponds and ditches should be deep in the middle and shallow around. If the contiguous farming area is large and the governance conditions are good, the surrounding irrigation and drainage ditches can also be used as temporary ponds or ring ditches for raising crabs in rice fields, so as to expand the crab raising area without reducing or affecting the rice field area.

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