Culture conditions of crabs in rice field

The area of rice fields where crabs are raised is 2 to 20 mu. Fields with fresh water quality, no industrial pollution in water source and sediment, convenient entry and drainage, and sufficient light should be selected. The bottom material should be clay soil, which is non-seepage and non-leakage, with a ridge height of 0.8mm and a slope of 1:2 or 1RV 2.5, and should be compacted to strictly prevent crevices in the ridge, resulting in water leakage or escape crabs.

Ring trenches are excavated along the inside of the ridge, with a width of 2 to 3 meters and a depth of 0.6 to 0.8 meters, as the main place for raising crabs. To dig a good field ditch, take the form of "ten" ditch or "well" ditch for crabs to climb into the paddy field to find food and hide. The width and depth of the trench are about 0.5 meters respectively, and are connected with the ring trench.

A temporary pond of sufficient area is usually dug at one end or one side of the field to cultivate bigeye larvae or temporary crab species, which can also be used when harvesting adult crabs, accounting for about 5% of the field and 1 meter deep. The total excavation area of raising crabs can generally account for 10% to 15% of the total area of rice fields.

Anti-escape facilities can be set up along the crab rice field around the plastic board or double-layer agricultural plastic film anti-escape wall, usually 50-60 cm high, 10-15 cm buried in the soil, supported and fixed with wooden piles. The escape wall is tilted inward at an angle of 20 degrees and 30 degrees.

The intake and drainage gates should be free of drainage and irrigation, and the water level should be easy to control, safe and reliable. The gate should be sealed with silk cloth to prevent crabs from escaping or enemy creatures from entering.

In the selection of rice varieties, the varieties with strong fertility tolerance, hard stem, lodging resistance, long growth period and high yield should be selected. Varieties that do not need to dry their fields should be given priority when selecting rice. During the period of river crab culture, if you need to dry the field for a short time, the water level drops to the surface of the paddy field.