In order to make full use of crab ponds, it is an important way to increase the economic benefits of crabs by increasing or replanting part of the green prawns during the crab raising process. The economic benefits resulting from the polyculture of crabs and shrimps can be paid for the cost of raising crabs. Then, the income from the sale of crabs is all net income. Therefore, many crab-rearing households use the crab ponds, and at the same time, they will raise some of the green shrimps and promote the harvest of crabs and shrimps.
Pond facilities
Crabs and shrimps belong to the same crustacean and their requirements for the pond are about the same. The area is generally suitable for 5 mu to 10 mu. The water depth is between 1 meter and 1.5 meters. This water depth is beneficial to the light and increase the dissolved oxygen in the water. At the same time, the sunlight is also beneficial to the growth of crab and shrimp carapace and the clam shell. molt. There should be less silt in the bottom of the pool to avoid decomposition and consumption of oxygen due to more humus. Water for aquaculture requires sufficient water, fresh water, convenient drainage, good physicochemical conditions of the water source, and a pH requirement of between 7 and 8, so as to avoid farmland sewage entering the water source and preventing pesticides from damaging crabs and shrimps. If you want to open a new pond, a simple way to open the ditch is to ditch around the pool. The ditch is 2 meters to 3 meters wide and about 1 meter deep. The soil removed by ditching is used to build levees. The levee specifications require that the ditch surface can retain a water depth of 0.8 to 1.2 meters, which is convenient for crabs and shrimps to inhabit at different depths of water, and is also conducive to the harvesting of crabs and shrimps. . This ditch is commonly referred to as crab ditch and shrimp shoal.
Before the breeding ponds are planted, the old ponds must be cleared of mud and flat bottoms and disinfected with drugs. Commonly used drugs are tea seed cake, quicklime and clear pond net, etc., with dosages of 40 kg, 75 kg and 10 kg per mu, respectively. The specific usage is to dissolve the drug in the inner barrel or other container and splash it in the whole pool. After the drug is used for 7 days to 10 days, it can be stocked after the test water proves to be non-toxic. According to the concealed habits of crabs and shrimps in aquatic plants, some plants can be planted around the pond.
Seed stocking
For crab ponds that have mixed penaeid shrimps, some crabs (ie, large-eyed larvae) can be raised to grow into juvenile crabs. You can also stock some juvenile crabs from period III to period V quickly. Crab farming crabs. Stocking time, stocking specifications, and stocking densities were as follows: Crabs were stocked at the end of April and early May, stocking 1 kg to 1.5 kg per acre, and crabs from the third period to the V period were stocked from June to July. About 3,000 kilograms, stocking 1.5 kilograms to 3 kilograms per acre; 1 instar crabs stocked before and after the Spring Festival, the specifications for 60 to 160 per kilogram, stocking 10 kilograms to 20 kilograms per acre.
The shrimp stocking can be put into the shrimp species in a simple way, that is, 0.5 kg to 0.67 kg of egg-holding shrimp per acre pond. It is best to collect the egg-holding shrimp that has emerged from the eyes and can quickly hatch from April to May. Because egg-holding shrimps have generally been refined, there is no need to store additional males. The egg-holding shrimps are kept in a small cage in crab ponds and stocked at 0.5 kg per square meter. After about 7 days to 10 days, they can be hatched with egg-shrimps. After that, the females are sold on the market and the shrimps are left in the pool. To continue breeding, each egg-holding shrimp can usually produce more than 4000 shrimp seedlings.
In order to better purify the water quality, each mu can be used with a breeding scale of 150 grams of squid 20 to 30, and squid 30 to 50.
Ventilation is one of the most important components in a successful greenhouse.
If there is no proper ventilation, greenhouses and their growing plants can become prone to problems. The main purposes of ventilation are to regulate the temperature and humidity to the optimal level, and to ensure movement of air and thus prevent build-up of plant pathogens (such as Botrytis cinerea) that prefer still air conditions. Ventilation also ensures a supply of fresh air for photosynthesis and plant respiration, and may enable important pollinators to access the greenhouse crop.
Greenhouse Circulation Fan,Greenhouse Ventilation Fan,Automated Greenhouse Ventilation Fan
JIANGSU SKYPLAN GREENHOUSE TECHNOLOGY CO.,LTD , https://www.thgreenhouse.com