Techniques of fish culture in cross-season ponds

The traditional pond fish culture technology in China is to release fish species at the beginning of the year and catch them on the market at the end of the year, which has been accepted by the majority of fish farmers. However, the outstanding problem of this breeding method is that it is listed centrally in winter, and the product price is on the low side, especially for conventional breeders. The cross-season pond fish culture technology can delay the time to market, which can obtain higher yield and better profit. The main technical points are as follows: (1) pond conditions and ① pond conditions; fish ponds require an average water depth of more than 15 meters, non-leakage, water source is more convenient. ② pond repair; after fishing the pond fish on the market from August to October every year, trim the pond ridge, where possible, remove too much silt, and then clean the pond with 150kg quicklime per mu of water. ③ application of base fertilizer: according to the water surface per mu, 200ml 300kg of mature fertilizer was applied as base fertilizer. ④ cross-season fish culture grass carp fingerling, according to 100 grass carp per mu equipped with 0.2mu of field or land recommended fish culture. (2) the source of ① fingerling: the original pond captive culture or purchased fish species can be used as the source of interseasonal culture. ② stocking time and fish fingerling disinfection: the stocking time of fish fingerling is from mid-August to early October every year. Fish fry are soaked in 5% salt water for 10 minutes before stocking. If grass carp are mainly raised in ponds, grass carp need to be injected with inactivated vaccine against grass carp hemorrhagic disease. (3) ① mixed culture model: stocking quantity and ratio of grass carp, silver carp, bighead carp, Pengze crucian carp, carp, catfish and other species. ② is mainly based on crucian carp culture model; per mu, there are 10 Pengze crucian carp, 1,001,200 Pengze crucian carp, 100,130 silver carp per kilogram, and 200,300 yellow catfish (Pelteobagrus fulvidraco). In May of the following year, 300 grass carp, 300 silver carp and 200 bighead carp can be put on each mu of water. (4) raising and management ① feed feeding: fish fingerling can be fed pellet feed according to 3mur4% of fish body weight, twice a day, once in the morning and once in the afternoon, and the feeding method is the same as that of fish culture in ponds. After the end of November, as the temperature dropped, the daily feeding volume gradually decreased to 2% of the fish weight, and the feeding frequency was changed from twice a day to once a day at noon (extreme weather can not be fed). After the end of February of the following year, the amount of feed gradually rebounded to 2mi 4%. ② green fodder feeding: the whole feeding stage needs to be fed green fodder in winter. The principle is that grass carp are not left over on the same day, daily feeding times are binomial before mid-December, once a day in winter, and then changed to two times at the beginning of March. After mid-March, the daily intake of green fodder should be properly controlled, based on the principle of feeding up to 80% of grass carp (about 0.3 Mel and 0.4 kg of grass carp per kilogram), so as to avoid causing fish disease. ③ water quality control; the whole feeding process needs to keep the pond water fat, lively and fresh, and the pool water should be added to the maximum amount in the tender winter. When the weather changes frequently in spring, pay attention to adjust the water quality to avoid the accident of dead fish in the floodpond. (5) fishing listing when the fish are raised to May-June, most of the pond fish can reach the listing specifications, at this time, the adult fish can be gradually listed on the market according to the market price, until the fishing is finished in mid-August, and the next round of culture can be resumed. (6) Note: ① is mainly grass carp or in ponds with large stocking capacity of grass carp, the onset time of grass carp is about one month earlier than that in conventional culture ponds, so it is necessary to start fish disease prevention in mid-March. The fish carrying capacity of ② cross-season fish culture is larger than that of conventional fish culture ponds from April to June every year, so the possibility of floating head and flooding pond is greater during this period. In the season with frequent weather changes, attention should be paid to adjust the water quality and timely add new water to prevent floating head and flooding pond.