In saline-alkali ponds, the water quality of ponds is brackish and brackish because of the influence of soil components. In the process of aquaculture, there is a certain gap between pond aquaculture production and economic benefits compared with non-saline ponds, and the disease is more serious. In order to solve the problems existing in the pond cultivation of saline-alkali land and maximize the production efficiency of the saline-alkaline ponds, the Ministry of Agriculture in the mid-1990s successively issued a scientific and technological project on low-lying saline-alkaline land pond culture technologies in order to promote Saline-alkali ponds are a healthy development of the aquaculture industry. The author is presiding over the "Low-lying saline-alkaline pond fish farming technology" project issued by the Ministry of Agriculture, and absorbing the latest scientific and technological achievements and advanced technologies at home and abroad, summarizing a set of saline-alkaline pond culture techniques for reference only.
--- Selection of cultured species The principle of salt-alkali pond culture species selection is broad salt tolerance, high alkalinity resistance, high hardness, high growth rate, and strong disease resistance. For brackish water ponds with a water salinity of 1‰-3‰ and an alkalinity of 100-200mg/L, tilapia, barracuda, mackerel, mackerel, prawns, squid, and carp are suitable for the main species. Fish, grass carp, river crabs, etc.; For saltwater ponds with a salinity of 3‰ to 5‰, alkalinity of 150mg/L to 200mg/L, the main breeds are tilapia, barracuda, American redfish, and squid. Salmon, South American white shrimp, etc.
Second, breeding mode
1. The mode of fish farming polyculture has higher yields and better economic benefits. The polyculture modes used are: 1 Main tilapia model: tilapia harvesting accounts for 60% to 80% of the total pond production, stocking species size 50g/tail to 100g/tail, stocking density 800/mu. 1200 tail/mu. Brackish water ponds can be mixed with barracuda, bream, bream, squid, and saltwater ponds can be mixed with barracudas and squid. 2 The main cultured barracuda model: Barracuda harvesting accounts for 60% to 80% of the total pond production, stocking species size 75g/tail to 100g/tail, stocking density 800 to 1000 mu/mu. Brackish water ponds can be mixed with tilapia, oysters and clams, and saltwater ponds can mix tilapia and mackerel. 3 Mainly adopting the American redfish model: The harvest of American redfish accounts for 60% to 80% of the total pond production, the stocking species size is 75g/tail 100g/tail, and the stocking density is 800 tail/mu to 1200 tail/mu. Brackish water ponds can be mixed with tilapia and clams, and saltwater ponds can be mixed with tilapia and barracuda. (4) The mode of raising main carp: The harvested carp accounts for 70% to 80% of the total pond production, the stocking size is 75g/tail to 150g/tail, and the stocking density is 500/mu to 800/mu. Brackish water ponds can be mixed with barracudas, tilapia, grass carp, catfish, squid, squid, head locusts, etc., and saltwater ponds with a pool water no more than 5 å¯ can be mixed with tilapia, barracuda, pupa, etc. Hey. 5 The main mode of raising squid: The squid harvesting yield accounts for 60% to 80% of the total pond production, the stocking species size is 50g/tail to 100g/tail, and the stocking density is 1200 to 1800/mu. Brackish water ponds can be mixed with head lice, oysters, clams, barracudas, tilapia and squid, black fish, squid, and other ferocious fish. Ponds with a pool water no more than 5 ç› can be mixed with a saltwater pond. Fish, barracuda, clams, clams, squid, etc. 6 The main support group head lice mode: The group head lice harvest yield accounts for 60% to 80% of the total pond production, stocking species size 75g/tail to 150g/tail, stocking density 800 to 1200/mu. Brackish water ponds can be stocked with ferocious fish such as squid, sea bream, bream and squid, black fish, and squid. 7 The mode of raising grass carp: The harvest of grass carp accounts for 60% to 80% of the total pond production. The size of the stocked fish is 100g/tail to 150g/tail, and the stocking density is 500/mu to 800/mu. Brackish water ponds can be mixed with ferocious fish such as squid, head bream, clam, bream and squid, black fish, and squid. In the above seven modes, the main culture species was released to the pond earlier than other species. When the main culture species were domesticated and concentrated on food intake, other seed crystals were placed. At the same time, in order to ensure the feeding and normal growth of the main species, polyculture The species of fish species should not exceed the specifications of the main species.
2. The cultivated species of the shrimp culture model is Penaeus vannamei, and the farming modes adopted are monoculture and polyculture. 1 Single-feeding mode: Only white shrimps of Penaeus vannamei are used in ponds, and the stocking size is 1.0cm to 3.0cm in length, and the stocking density is 20,000 to 60,000/mu. 2 polyculture mode: the main species of white shrimp in South America, micro-water ponds can be mixed with summer barnacles, carp summer flowers, salt water ponds can be mixed barracudas summer flowers. The stocking size of Penaeus vannamei is 1.0cm to 3.0cm in body length, and the stocking density is 10,000 to 50,000/mu. The mixed breeds should be released when the South American shrimp has a body length of 5cm or more.
Third, water quality control technology Saline-alkali pond water quality compared with the quality of freshwater ponds has two aspects: First, high salinity, high alkalinity, low phosphorus content; Second, low temperature season (water temperature below 22 °C), water phytoplankton Small blue-green algae are the main species, and during the high-temperature season, microcystis and rotifers proliferate. The above-mentioned two aspects have direct effects on fish production: fish growth rate is slowed down, disease resistance is reduced, and it is prone to hypoxic floating heads, and it is susceptible to NH3+-N poisoning and NO2--N poisoning. Therefore, the water quality is regulated. Targeted technical measures should be taken to reduce the salinity of water quality, maintain the appropriate type and amount of plankton in the water, and maintain a high dissolved oxygen content.
1. Maintain a high water level in the pond and reduce the degree of salt infiltration around the pond. The depth of the pool water is preferably 1.8m to 2.0m.
2. During the dry season, the ponds regularly inject fresh water to make up for leakage and evaporation. During the high temperature season, the pond regularly discharges part of the pool water. The displacement is 15% to 20% of the original pond water, and then the new water is injected.
3. Fertilization. The purpose of fertilization is to provide nutrients for phytoplankton to maintain appropriate levels of phytoplankton in water, increase dissolved oxygen levels in pool water, reduce harmful gas content, and provide biofeeds for filter-feeding fish. Commonly used fertilizers include manure and chemical fertilizers: commonly used manures are human excrement and livestock excrement. Chicken manure is best used. Manure is used from May to June, and manure must be fully fermented and disinfected before use. The amount of manure is transferred to the whole pool after the manure is adjusted to slurry. Each time the amount is 100kg/mu to 150kg/mu, manure should be avoided in the summer to prevent the increase of organic matter quality due to the use of manure, the increase of oxygen consumption and the induction of rotifers. A lot of birth. Fertilizers should use neutral or acidic fertilizers, and should not use fertilizers containing sodium and potassium ions to accumulate salinity in water-repellent substances. The types of fertilizers commonly used include urea, ammonium bicarbonate, ammonium sulfate, and superphosphate, which are usually used during the summer heat season. After the fertilizer is fully dissolved, the whole pool will be spilled, and the amount will be 1.5kg/mu~2.0kg/mu each time. In ponds that are prone to trigeodes poisoning, the use of ammonium bicarbonate fertilizers is effective, and NH4+ can inhibit the propagation of Algae.
4. Aging ponds use microbial preparations such as EM bacteria solution or photosynthetic bacterial bacteria liquid every 15 days during the summer high temperature season to reduce the content of harmful substances such as ammonia nitrogen, nitrite nitrogen, and hydrogen sulfide in water, and to decompose organic matter and reduce organic matter. Oxygen consumption increases the dissolved oxygen content of the water. For overwintering ponds, water quality improvers such as zeolite powder and medical stone should be poured before the winter and the dosage is 50kg/mu to 100kg/mu.
Fourth, feed and feeding feed The best use of artificially formulated pellet feed is to use the feed that requires balanced nutrition, high nutritional value, good physical properties, does not contain banned drugs, and the feed is fed on the premise of following the “Four Sets†principle. , daily management should pay attention to:
1. Feed early. The fish should be fed and acclimated on the second day after the human pool. The early feeding should be used to enhance the fish body constitution, shorten the growth recovery period of the fish species due to the overwintering period, and extend the breeding growth period. After the shrimp enters the pond, artificial diets are fed from 3 to 5 days after entering the pond to make up for the lack of basic food organisms in the water and the unbalanced biological nutrients in the basic diet, thus promoting the growth of shrimps.
2. Stop eating late. For saltwater ponds, due to the high salinity and alkalinity of water quality, there is a certain gap between the growth rate of the main carp carp and the fish body constitution and the fish cultured in freshwater ponds. Therefore, it should be extended as much as possible in the later period of cultivation. The feeding period, especially wintering ponds, is usually defined by the temperature of the water. When the water temperature is below 15°C, feeding is stopped.
V. Disease Prevention
1. Types of major diseases Fish diseases include salmon hemorrhagic disease, carp hemorrhage, third generation helminthosis, trigeminosis, rotifer mass reproduction, ammonia nitrogen and nitrite poisoning, and fatty liver disease. Shrimp diseases include white spot virus disease and ciliate disease.
2. Prevention and control measures Fish diseases and freshwater ponds have the same disease prevention and control methods. Shrimp diseases are the same as seawater ponds.
Sixth, wintering management
1. Before closing the ice in the pond, take measures such as feeding baits and disinfecting the water body to eliminate fish diseases, kill parasites and pathogens in the water, and ensure healthy winter fish.
2. After the ice is sealed in the pond, it is necessary to regularly replenish fresh water. It is advisable to add 10% of the amount of water to the pool each time. According to the amount and type of plankton in the pond, it is suitable to fertilize fertilizer. The amount of fertilizer applied is lkg/mu~2kg/mu.
3. After the ice melts, check the fish body and water quality, and take corresponding measures according to the inspection conditions.
--- Selection of cultured species The principle of salt-alkali pond culture species selection is broad salt tolerance, high alkalinity resistance, high hardness, high growth rate, and strong disease resistance. For brackish water ponds with a water salinity of 1‰-3‰ and an alkalinity of 100-200mg/L, tilapia, barracuda, mackerel, mackerel, prawns, squid, and carp are suitable for the main species. Fish, grass carp, river crabs, etc.; For saltwater ponds with a salinity of 3‰ to 5‰, alkalinity of 150mg/L to 200mg/L, the main breeds are tilapia, barracuda, American redfish, and squid. Salmon, South American white shrimp, etc.
Second, breeding mode
1. The mode of fish farming polyculture has higher yields and better economic benefits. The polyculture modes used are: 1 Main tilapia model: tilapia harvesting accounts for 60% to 80% of the total pond production, stocking species size 50g/tail to 100g/tail, stocking density 800/mu. 1200 tail/mu. Brackish water ponds can be mixed with barracuda, bream, bream, squid, and saltwater ponds can be mixed with barracudas and squid. 2 The main cultured barracuda model: Barracuda harvesting accounts for 60% to 80% of the total pond production, stocking species size 75g/tail to 100g/tail, stocking density 800 to 1000 mu/mu. Brackish water ponds can be mixed with tilapia, oysters and clams, and saltwater ponds can mix tilapia and mackerel. 3 Mainly adopting the American redfish model: The harvest of American redfish accounts for 60% to 80% of the total pond production, the stocking species size is 75g/tail 100g/tail, and the stocking density is 800 tail/mu to 1200 tail/mu. Brackish water ponds can be mixed with tilapia and clams, and saltwater ponds can be mixed with tilapia and barracuda. (4) The mode of raising main carp: The harvested carp accounts for 70% to 80% of the total pond production, the stocking size is 75g/tail to 150g/tail, and the stocking density is 500/mu to 800/mu. Brackish water ponds can be mixed with barracudas, tilapia, grass carp, catfish, squid, squid, head locusts, etc., and saltwater ponds with a pool water no more than 5 å¯ can be mixed with tilapia, barracuda, pupa, etc. Hey. 5 The main mode of raising squid: The squid harvesting yield accounts for 60% to 80% of the total pond production, the stocking species size is 50g/tail to 100g/tail, and the stocking density is 1200 to 1800/mu. Brackish water ponds can be mixed with head lice, oysters, clams, barracudas, tilapia and squid, black fish, squid, and other ferocious fish. Ponds with a pool water no more than 5 ç› can be mixed with a saltwater pond. Fish, barracuda, clams, clams, squid, etc. 6 The main support group head lice mode: The group head lice harvest yield accounts for 60% to 80% of the total pond production, stocking species size 75g/tail to 150g/tail, stocking density 800 to 1200/mu. Brackish water ponds can be stocked with ferocious fish such as squid, sea bream, bream and squid, black fish, and squid. 7 The mode of raising grass carp: The harvest of grass carp accounts for 60% to 80% of the total pond production. The size of the stocked fish is 100g/tail to 150g/tail, and the stocking density is 500/mu to 800/mu. Brackish water ponds can be mixed with ferocious fish such as squid, head bream, clam, bream and squid, black fish, and squid. In the above seven modes, the main culture species was released to the pond earlier than other species. When the main culture species were domesticated and concentrated on food intake, other seed crystals were placed. At the same time, in order to ensure the feeding and normal growth of the main species, polyculture The species of fish species should not exceed the specifications of the main species.
2. The cultivated species of the shrimp culture model is Penaeus vannamei, and the farming modes adopted are monoculture and polyculture. 1 Single-feeding mode: Only white shrimps of Penaeus vannamei are used in ponds, and the stocking size is 1.0cm to 3.0cm in length, and the stocking density is 20,000 to 60,000/mu. 2 polyculture mode: the main species of white shrimp in South America, micro-water ponds can be mixed with summer barnacles, carp summer flowers, salt water ponds can be mixed barracudas summer flowers. The stocking size of Penaeus vannamei is 1.0cm to 3.0cm in body length, and the stocking density is 10,000 to 50,000/mu. The mixed breeds should be released when the South American shrimp has a body length of 5cm or more.
Third, water quality control technology Saline-alkali pond water quality compared with the quality of freshwater ponds has two aspects: First, high salinity, high alkalinity, low phosphorus content; Second, low temperature season (water temperature below 22 °C), water phytoplankton Small blue-green algae are the main species, and during the high-temperature season, microcystis and rotifers proliferate. The above-mentioned two aspects have direct effects on fish production: fish growth rate is slowed down, disease resistance is reduced, and it is prone to hypoxic floating heads, and it is susceptible to NH3+-N poisoning and NO2--N poisoning. Therefore, the water quality is regulated. Targeted technical measures should be taken to reduce the salinity of water quality, maintain the appropriate type and amount of plankton in the water, and maintain a high dissolved oxygen content.
1. Maintain a high water level in the pond and reduce the degree of salt infiltration around the pond. The depth of the pool water is preferably 1.8m to 2.0m.
2. During the dry season, the ponds regularly inject fresh water to make up for leakage and evaporation. During the high temperature season, the pond regularly discharges part of the pool water. The displacement is 15% to 20% of the original pond water, and then the new water is injected.
3. Fertilization. The purpose of fertilization is to provide nutrients for phytoplankton to maintain appropriate levels of phytoplankton in water, increase dissolved oxygen levels in pool water, reduce harmful gas content, and provide biofeeds for filter-feeding fish. Commonly used fertilizers include manure and chemical fertilizers: commonly used manures are human excrement and livestock excrement. Chicken manure is best used. Manure is used from May to June, and manure must be fully fermented and disinfected before use. The amount of manure is transferred to the whole pool after the manure is adjusted to slurry. Each time the amount is 100kg/mu to 150kg/mu, manure should be avoided in the summer to prevent the increase of organic matter quality due to the use of manure, the increase of oxygen consumption and the induction of rotifers. A lot of birth. Fertilizers should use neutral or acidic fertilizers, and should not use fertilizers containing sodium and potassium ions to accumulate salinity in water-repellent substances. The types of fertilizers commonly used include urea, ammonium bicarbonate, ammonium sulfate, and superphosphate, which are usually used during the summer heat season. After the fertilizer is fully dissolved, the whole pool will be spilled, and the amount will be 1.5kg/mu~2.0kg/mu each time. In ponds that are prone to trigeodes poisoning, the use of ammonium bicarbonate fertilizers is effective, and NH4+ can inhibit the propagation of Algae.
4. Aging ponds use microbial preparations such as EM bacteria solution or photosynthetic bacterial bacteria liquid every 15 days during the summer high temperature season to reduce the content of harmful substances such as ammonia nitrogen, nitrite nitrogen, and hydrogen sulfide in water, and to decompose organic matter and reduce organic matter. Oxygen consumption increases the dissolved oxygen content of the water. For overwintering ponds, water quality improvers such as zeolite powder and medical stone should be poured before the winter and the dosage is 50kg/mu to 100kg/mu.
Fourth, feed and feeding feed The best use of artificially formulated pellet feed is to use the feed that requires balanced nutrition, high nutritional value, good physical properties, does not contain banned drugs, and the feed is fed on the premise of following the “Four Sets†principle. , daily management should pay attention to:
1. Feed early. The fish should be fed and acclimated on the second day after the human pool. The early feeding should be used to enhance the fish body constitution, shorten the growth recovery period of the fish species due to the overwintering period, and extend the breeding growth period. After the shrimp enters the pond, artificial diets are fed from 3 to 5 days after entering the pond to make up for the lack of basic food organisms in the water and the unbalanced biological nutrients in the basic diet, thus promoting the growth of shrimps.
2. Stop eating late. For saltwater ponds, due to the high salinity and alkalinity of water quality, there is a certain gap between the growth rate of the main carp carp and the fish body constitution and the fish cultured in freshwater ponds. Therefore, it should be extended as much as possible in the later period of cultivation. The feeding period, especially wintering ponds, is usually defined by the temperature of the water. When the water temperature is below 15°C, feeding is stopped.
V. Disease Prevention
1. Types of major diseases Fish diseases include salmon hemorrhagic disease, carp hemorrhage, third generation helminthosis, trigeminosis, rotifer mass reproduction, ammonia nitrogen and nitrite poisoning, and fatty liver disease. Shrimp diseases include white spot virus disease and ciliate disease.
2. Prevention and control measures Fish diseases and freshwater ponds have the same disease prevention and control methods. Shrimp diseases are the same as seawater ponds.
Sixth, wintering management
1. Before closing the ice in the pond, take measures such as feeding baits and disinfecting the water body to eliminate fish diseases, kill parasites and pathogens in the water, and ensure healthy winter fish.
2. After the ice is sealed in the pond, it is necessary to regularly replenish fresh water. It is advisable to add 10% of the amount of water to the pool each time. According to the amount and type of plankton in the pond, it is suitable to fertilize fertilizer. The amount of fertilizer applied is lkg/mu~2kg/mu.
3. After the ice melts, check the fish body and water quality, and take corresponding measures according to the inspection conditions.