First, what are the benefits of paddy fish farming?
Rice-field fish farming refers to a form of production in which paddy field's shallow water environment is used in conjunction with human intervention to grow rice and raise fish to increase production efficiency per unit area of ​​paddy field. Rice-field fish farming combines organic farming and planting, and rice and fish coexist and benefit each other, so that the ecosystem of rice fields can be rationally transformed both structurally and functionally, so as to maximize the "loading power" of rice fields.
The purpose of fish farming in rice paddies is to make full use of all biological and non-biological resources in the paddy fields to convert them into rice and fish, in order to increase the economic, ecological and social benefits of paddy field production. The combination of rice and fish is conducive to improving the structure and function of farmland ecosystems. The main benefits are the following four points:
First of all, paddy field fish can promote rice production. Rice-field fish farming is a kind of connotation expansion and reproduction, which is the reuse of land and resources. It can produce aquatic products without additional occupation of cultivated land. Experiences from various regions have shown that the development of fish farming in paddy fields will not only affect rice yield but also increase rice production. Rice paddies generally increase rice yield by 5%–10%, with higher yields by 14–24%.
Second, paddy fish farming can increase the supply of aquatic products to the community and enrich people's "vegetable baskets." In recent years in Jiangsu, Sichuan, Guizhou and other places, paddy field fish farming has become one of the main ways of local aquaculture. Rice field fish farming can be listed on a balanced basis, which plays an important role in stabilizing the supply of aquatic products, stabilizing market prices, meeting the needs of “vegetable baskets†and improving people’s dietary structure. Especially in areas where water resources are lacking and where traffic is congested, fish farming in paddy fields, local production, and local sales effectively solve the long-term problem of “difficulties in eating fish†in these areas.
Third, paddy fish farming can significantly increase farmers' income. Rice field fish increase both grain and fish, and it can make less fertilizer and less sprinkling of pesticides in paddy fields, save labor, increase income and reduce expenditures. In general, fish farmers can increase their income by 220 yuan per mu. High-standard rice-fish farming projects can raise fish in paddy fields by 350 yuan per mu. Using paddy fields to cultivate famous special aquatic products and carrying out rice-fish-mushroom triple compound breeding, the rice field per mu can increase more than 1,000 yuan.
Fourth, fish farming in rice fields has promoted the optimization of the ecological environment and enhanced its ability to resist natural disasters. Due to fish farming in paddy fields, the height of field ridges will be increased accordingly, and ravines will be excavated, which will greatly increase water storage capacity and will help prevent floods and droughts. In some hilly regions, the implementation of rice-fish farming projects can increase water storage capacity by 200 cubic meters per mu, which greatly enhances drought resistance. For some drought-ridden areas, the paddy fields with fish farming can effectively delay the drought due to the large water storage capacity. The effect of fish farming in paddy fields on the improvement of the environment is mainly manifested by its relatively effective disinfestation effect. According to the test, the density of rice larvae in fish farming is 80% lower than that in non-fish farms. The main reason is that fish raised in paddy fields consume large amounts of mosquito larvae and snails, which can raise the incidence of serious diseases such as malaria, filariasis, and schistosomiasis.
Second, what matters should be paid attention to in the rice field fish breeding construction?
(1) Selection of fish farm plots Any plots with sufficient water sources, good water quality, strong water retention capacity, convenient drainage and irrigation, irrepressible drought, and flash floods can all be used for fish rearing. In particular, in mountainous areas, it is necessary to choose those rice fields that have guaranteed water sources, are full of sunlight, and are not washed by floods. Shaditian should not adopt the “Tianyu†method to submerge irrigated paddy fields and cold-water immersed fields.
(II) Construction of Field Projects
1. There is less investment in general field projects for general rice field fishery field construction. Farmers use the idle season to invest and dig for fish and fish ditch. Its engineering features are: using earth to increase, strengthening, and widening field rakes, the fish ditch fish need to be excavated every year.
(1) Fish gills account for 5-8% of the total land area. One or two acres of plots will be dug, one or three or more acres of rice paddies may be excavated 2-3, and the fishing rods are mostly built in the middle of the field or on the side of the field, excavating a square or round fishing rod, with a depth of 1-1.2 meters. The fish ditch center groove communicates with each other. The excavation time can be 30-40 days before transplanting. After the excavation, it should be sorted every 10 days, and the fish should be finished 3-4 times.
(2) The fish ditch is excavated when the seedlings turn green after transplanting, and the seedlings can be transplanted on the edge of the fish ditch. The area of ​​the fish ditch is 3-5% of the total area, the width of the ditch is 40 cm, and the ditch is 50 cm deep. The shape of the fish ditch can be dug into "10", "day", "tian", or "well" shapes according to the size of the paddy fields, and be connected to the fishing rods. Can be finished twice in the field and heading.
(3) Raise the height of the field and remove the soil from the digger to increase the height of the field. Normally, the earthworms should be raised to about 40 cm, widened by more than 50 cm, and hammered firmly to prevent fish from escaping or flooding during heavy rains.
(4) Each of the built-in intakes and drainage outlets shall be provided with one inlet and one for water outlet, and the other one shall be provided with one or three overflow gaps according to the size of the plots. The inlet and outlet openings are generally open at opposite corners of the paddy field, and the inlet and outlet openings are determined according to the amount of rice paddy drainage. The water intake is about 10 cm higher than the field surface, and the water outlet should be parallel or slightly lower than the field surface. In the terraces of hilly and mountainous regions, the drainage of the upper field is often the inlet of the next field, and the series connection is adopted. The paddy fields in the plain area are mostly drained and drained, and the water conservancy facilities are relatively complete. Some of them are the same as those in the hilly areas.
(5) The rice paddy fields and drainage ports installed on the barrages should be installed on the corresponding two corners of the field to make the water flow clear. Note: Drain outlets should be solid and firm. Bars should be installed to prevent fish escape and miscellaneous fish from entering the fish-raising paddy fields. Bars can generally be made of bamboo or wire braided into a mesh shape, the size of which is based on the size of the fish. The barrage is 30 cm wider than the inlet and outlet, and the upper end of the barrage is more than 10-20 cm. The lower part is embedded in the lower clay soil 30 cm.
2. The permanent field project of the permanent paddy field fishery field project requires the use of bars, slabs, cement prefabricated plates or bricks to reinforce the field rakes, fishing rods and inlets and outlets. Tian Hao high, ditch width, ditch depth, and large. Gullies account for 8%-15% of the total area. This kind of project is of good quality and has a long service life. It only needs to excavate and tidy the fish ditch every year, and it is not necessary to build ridges and fish gills.
(1) The fishing rod (fish slip) is actually a small pond, which accounts for 6-8% of the total area and 1.5-2.5 meters deep. The fishing rod is generally located at the side of the field or in the middle of the field. Avoid selection at Tianjiao and often passing pedestrians. Tian field. Rod shape is oval, square or rectangular. The fishing rods are best dug into a two-step downhill type, that is, the excavation is made at a slope ratio of 1:0.5 at the upper 1 meter, and the lower part is excavated at a slope ratio of 1:1, leaving a 30 cm wide platform between the two parts. . Slope protection with slate, bar, brick or cement prefabricated panels. In order to prevent silt from entering the gills, a 20 cm high and 30 cm wide grate should be built on the edge of the gutter. The number of fishponds built depends on the size of the plots, generally 1-2 acres of rice fields will be built, and 3-5 acres of rice fields will need to be built. Each area will be 50-100 square meters. The fish larvae built in the center of the field generally need to open 4 gaps, and the gap in the fish larvae is mainly connected with the fish ditch. The purpose of the surimi is to apply chemical fertilizers, pesticides, weeding, and sun drying; the fish can temporarily gather in the cocoon; in summer when the water temperature is high, the fish can avoid the heat in the surimi; when the drought occurs, the fish can gather in the trough, Living in the middle of life, normal growth. The bait station can be set in the fish larvae, and the bait can be put on the bait station set in the urn to check the fish's feeding and activity.
(2) The fish ditch is set in the fish ditch rice field and should be determined based on the size of the plot and the shape of the field. Generally account for 3-5% of the total field area, excavated into a "1" shape, "10" shape, "Japanese" shape, "Tian" shape, "encirclement" shape and so on. The ditch is 0.8-1m wide and 0.5-0.7m deep. Center fish ditch: Shunchang Tianbian, open a ditch in the center of the field; around the fish ditch: 1.5 meters away from the field to excavation. Each year should be excavated 20-30 days before planting, 5-7 days before planting, and then finishing 1-3 times, deep foot field, soaking fields, to be more 2-3 times, the fish ditch was formed. (The rice fields in the ditch are no longer dug trenches).
(3) Heightening, widening, and strengthening of the construction of Tianshui Tianyu can be carried out simultaneously or before the construction of fishing rods, followed by construction of Tianshao. Tian Hao is 1-1.2 meters high and the dome is 0.6-0.8 meters wide. After the first stone or cement board or brick and cement is used to harden, the dry earth in the former Tiantian will be filled with cracks. Tian Hao used a piece of stone to build one intake and one drain, and to maintain multiple levels of water level and flood discharge. The water level should be kept above 0.3 meters (200 cubic meters per mu), and fish traps should be installed in front of the drainage outlets.
(4) Intake and drainage systems and the installation of fish and fishery facilities The construction of the intake and drainage systems shall determine the width, depth and depth of the drainage channels (channels) according to the size of the rainwater harvested in the rice fields. Generally, paddy fields are formed and upstream water sources are guaranteed. Inlets and drains should be slightly wider and deeper. Intake and drainage systems should be built outside the field and cannot be connected in series in rice fields. The inlet and outlet openings should be in the field ridges that are relatively two-cornered in the paddy field, which can make the entire rice field flow smoothly. The size of the outlet should be determined according to the size of the field and the amount of water entering the storm. The inlet should be about 10 centimeters higher than the field surface, the outlet should be flat or slightly lower, and the general outlet width should be 1-1.5 meters. Prefabricated with strips of stone or cement, it will not collapse. The drain outlet shall be installed with two layers of bamboo foil or barbed wire so that it can be curved and inserted into the field using bamboo rods or steel bars. The two curved bamboo foils are about 0.5 meters apart, and they are denser than the one layer of the outlet to ensure that the fish species do not escape. The length of fish bamboo foil is 3 times that of the outlet. The second layer of bamboo foil is relatively thin and is mainly used to prevent debris from blocking the first layer of bamboo foil so as to ensure the smooth flow of drainage outlets. The length of the bamboo foil used for blocking debris is more than four times that of the drainage outlet. The upper end of the bamboo foil should be It is 0.5 meters higher than Tiantian and the lower end is better than 30 cm below hard mud. The water inlet should also be covered with a layer of bamboo foil to prevent the fish from escaping. It is also arc-shaped and the length is 2 times the inlet.
Third, what are the feeding and management techniques for paddy field fish breeding?
(I) Techniques for cultivation of fingerlings in paddy fields
1. Preparation of fry before stocking
1) Disinfection and water injection. Before the excavation of the fish ditch in the open car, the water in the field and the pupa is 6-10 cm, and 60-75 kg of lime are used per acre to disinfect the lime. The lime is added to dissolve water, and the lime is poured evenly into the fields and the pupa without cooling. In order to improve the effect, the next day Tweezers and other tools can be used to shake the muddy mud and muddy bottom, so that the lime mud can be fully mixed with the mud. After disinfection for 8-10 days, all vaccines can be released after the efficacy disappears. The depth of the fish is kept at 1/3 of the depth of the pool when the fish is in the pool.
2) Fertilizer water quality. Before the paddy field is put in fry, Tianshui should have a certain amount of fat. It is necessary to cast basal fertilizer before stocking, so that the "fat pool underwater" allows the fish to obtain a lot of high-quality palatable natural foods in order to speed up growth and improve survival. rate.
The young fish in the first lower pool swallows palatable zooplankton such as rotifers. According to experiments, 10,000 fish per liter of rotifers in the lower larvae of the fry, biomass is 20-40 mg/l. After fertilizing seedlings, bacteria and phytoplankton multiply first, followed by protozoa, rotifers, small horns, large branches and copepods. Therefore, the key problem in submerged ponds is to master basal fertilisers. In the time when the fish fry down the pond, it is the peak of rotifer breeding.
The time and amount of base fertilizer should vary depending on the type of fertilizer, the conditions of the pond, and the type of fry. The peak time of plankton after fertilization is also not the same. When the water temperature is above 20°C, the zooplankton can reach its peak in 4-7 days. The application of decomposed manure can be carried out 4-5 days before the fry drop. 120 kg per acre field, diluted with water, Quanchiposa. The application of big grass (green manure) should be carried out in the lower pool for 5-10 days, and 200 kg per mu. The big grass can be piled in a shallow place about 1 meter away from the side of the planter, allowing it to rot and decompose naturally, turning the grass in a few days. Fertilizer spreads into the water. After the leaves and stalks are rotted, the root residue will be removed. It should be noted that if the basal fertiliser is too early and the peak period of rotifers has passed, a large number of horny horns, especially large horny horns, will appear. Instead, they will compete with the saplings for oxygen and fight for space; if the fertilization is too late, there will be insufficient rotifers. The lack of palatable baits in the lower pool of fry will greatly affect the survival rate of fry.
2. Problems to be noticed by the fish fry in Shimoda (1) The temperature of the fry before being placed in the field cannot be too different from the temperature of the paddy field. If the temperature difference exceeds 5°C, the water temperature in the container must be gradually adjusted with Tanaka water. When the water temperature in the container is basically the same as the water temperature in the field, the fry can be put into the field. Otherwise, fry will have a "cold", and severe cases will cause massive deaths.
(2) Artificially propagated fry must be inflated, can swim flat, and can only eat the outside food before going to the pool (4-5 days after hatching). The pool is too early, the fish swimming ability is weak, the body is tender, and it is easy to cause death.
(3) It is necessary to wait until the medicinal properties of the Qingchi medicine have completely disappeared, otherwise the fish will be killed in large numbers.
(4) Check whether any enemy organisms are left in the pond. Before clearing the pond until the fry is released, the fry eggs may have frog eggs, cockroaches, aquatic insects, and residual wild fish. When necessary, fish fry nets should be used for 1-2 times to remove these predators.
(5) Fish fry and fingerlings should not be replaced with well water during transportation. Because the first temperature of the well water is low, the temperature difference between the water in the container and the seedling is large; the second is that the oxygen content is small; the third is the specific gravity, which can easily cause the uneven temperature of the water in the container; and the fourth is that the well water is alkaline or acidic. Stronger.
3, stocking (1) varieties of grass carp, carp, carp, tilapia, carp, carp, bream, carp, loach, Macrobrachium rosenbergii, shrimp and other varieties.
The stocking time is the traditional stocking method, and the stocking time is usually about 5 days after the rice is planted. After the seedlings return to green, the fry is directly placed in the paddy field. Nowadays, high-yielding fishery rice fields are excavated with larger fish gills. In order to prolong the growth period of fish, it is required that the fish be irrigated in the early spring season, and then put in the fish gills for raising. Put the fish into the field.
(2) Stocking density of fry The fry are directly cultivated to summer flowers, and the general stocking density is about 10,000 per mu. If it is a breeding ground for Oda and Sakamoto, due to shallow water, the stocking density can be 4-50000 watercress per acre. If the fish fry are first raised to black larvae fry, and then divided into pools, the general mu stocking density of 160,000; and then from Wuzi to 5 cm species of fish, the general mu stocking for 2-3 million. Reasonable stocking is the key to raising the survival rate of fry breeding, and at the same time, it also saves feed, fertilizer and manpower. The stocking density and the conditions of the cultivation pond, the quantity and quality of the feed and the fertilizer, the sooner or later of the stocking time, and the level of the breeding technique are closely related. In places with good conditions, the stocking density can be greater; otherwise, the stocking amount should be smaller.
4. Feeding management of fry fingerlings
1) Feeding and Fertilizing Feeding: Weeds, benthos, zooplankton, and rice pests in paddy fields can provide certain feed for fish. However, in order to obtain higher fish yields in paddy fields, it is not enough to rely on the food organisms in the field. It is necessary to feed the appropriate amount of feed like pond fish. Feeding should be implemented "three set": timing, quantitative, positioning. To acclimate the fish to concentrate in the potholes in the rice paddies, you can take a table in the fish pot and take the fish to the table to feed. Feeding amount depends on the size and quantity of the fish species. In the first few days after the release of the spray, the milk was fed once every afternoon and in the afternoon. The dosage was about 0.20 kg per 10,000 tails. When the fry were grown to 1.5-2 cm, they were fed with a certain amount of wheat flour and dried food. On the split, feed it twice in the afternoon. After a length of 3 cm, grass carp and quail species can be cast with 1-1.5 mm diameter pelleted feed and fine green duckweed and rice bran. On sunny days, the depth of the water is strong, and the fish can be fed more. In cloudy days, it is hot and shallow, and less feeding is required. The feeds fed will soon be eaten, and the amount of feeds will be increased on the second day; fish will not eat fast and there will even be residual baits, and feed intake should be reduced appropriately.
Fertilization: timely fertilization in paddy fields, can be used as rice fertilizer, but also for the omnivorous fish to provide some food. In principle, the fertilization is a small amount, many times, to keep the water color of the fish is often green, blue and green, usually 1 fermentation per acre fertilization farmyard fertilizer 25-30 kg.
2) Day-to-day management: After the fish is put in paddy fields, special management should be carried out so that it can be managed after it is released. For stocking fish before transplanting, the fish shall be returned to the pits and raised during the transplanting period. After the seedlings have returned to the green, they are allowed to swim back to the fields. Daily management should insist on morning and evening inspections of the fields. In the early morning, observe whether the fish has floating heads or become sick. In the evening, check the fish’s diet. Found fish floating head, should be filled with fresh water, it is best to live water string irrigation, in order to increase dissolved oxygen in water. Pay attention to checking whether there is a rat hole, collapse, leakage, etc. in the field. Frequently dredge the fish gills and fish ditch to prevent blockage of the mud, timely eradicate the weeds in the potholes, and remove the residual baits in the potholes. The spring plowing and transplanting, and the summer harvest to prevent the Tianzhong mud back into the pit. During the high temperature season, it is necessary to put a shady shade on the side of the fish pit and raft, and appropriately deepen the water level in the paddy fields so as to prevent the fish from becoming uncomfortable because the water is too shallow and the water temperature is too high. Always check the entrance and exit of fish to prevent fish from escaping.
3) Capture: Fishing before and after rice harvest, enough for the sale of the product specifications, not enough to transfer the product specifications to other waters. Where conditions permit, irrigation of deepwater intensive culture can be continued after rice is harvested and harvested until the end of winter and early spring to implement full-scale fish farming. This allows for higher yields and benefits.
When starting the fish, first dredge the ditch around the ditch and the main groove in the field, and then slowly drain the fish. The fish naturally concentrate in the gills, and then use a dip net or a net bag to fish. When capturing, the operation must be careful, careful not to hurt the fish body. Such as catching fish species, should be promptly placed in clean water or running water cages, so that it spit up the mouth and the mud in the mud, temporarily raised for one day, after disinfection and then transferred to the field, transferred to continue feeding.
In places where conditions permit, in order to increase fish production, round robin can be implemented. Usually, the fish that meets the specifications of the product will be caught and listed, and the fish species will be properly added according to the density of the fish.
What are the techniques for raising fish in paddy fields?
(i) Fish stocking
1. Stocking species: In the past, paddy fish farming was only a few species such as carp, carp, and grass carp. It has now been developed to stocking tilapia, carp, carp, carp, carp, river crab, loach, macrobrachium rosenbergii, and green Shrimp and other varieties, but also the development of Ping, bamboo shoots, vegetables, edible fungi and other production for integrated breeding. Different regions can choose stocking species according to different circumstances. In principle, all species suitable for pond culture can be cultured in paddy fields.
2, stocking time: generally promote early release, fish species less than 3 cm, can be stocked before transplanting, because the small individual fish, will not tilt the seedlings. At this time, the paddy field where the basal fertilizer is applied has a large population of plankton and benthic animals after plowing, which is particularly advantageous for the growth of fry. Practice has proved that before and after transplanting into the same specifications of the species of fish, transplanting before feeding only more than 15 days after transplanting, but the field when the individual than after transplanting into the increase of more than 100 grams. For fish species 6-10 cm, it is best to wait until the seedlings turn green before putting them in. In the Yangtze River basin and South China, the use of paddy fields for fish rearing should be generally completed before the Spring Festival. Putting seeds before the Spring Festival, first, most of the fish in the adult fish field have been harvested; second, the fish's ability to move is weak, which facilitates fishing. The water temperature is low, and the scales of the fish are tight. In fishing and stocking operations, it is not easy to be injured, and the incidence and mortality during feeding can be reduced; the third is early restocking to extend the growth period. The stocking of fish should be carried out on a sunny day, and the weather in cold and snow can not be stocked to prevent the fish from being frosted during fishing operations and transportation.
3, stocking methods: winter and spring farming season, excavation of a good fishing rod, fish pit. For paddy fields where the fish were raised last year, it is better to refit the fishing rods, fish pits, etc. to remove the weeds. Before stocking, drain pits, rakes, and expose them to the sun for a week or so, and then pour about 10 centimeters deep, disinfect them with quick lime, and apply 50 kg of quick lime. After another week, fill enough water to fertilize 300 kilograms per acre to properly fertilize water. After 4-5 days, fish species can be released for feeding. Stocking species requires a healthy body, no disease and no injury, and the specifications of the same batch of fish should be neat. Before stocking, the fish should be disinfected with a fish bath.
4, stocking number: According to the size of the fish to determine the number of fish stocking. Paddy field cultured adult fish, promote the stocking of large-sized fish species, generally about 8 to 15 centimeters of large-sized fish species per acre of rice fields, about 8 to 15 centimeters of large-sized fish species per acre of high-yielding fish and rice fields. 800 tails. The specific amount of stocking should be adjusted according to local conditions, and it should be appropriately increased or decreased according to the ecological conditions of the paddy fields, the production requirements and the size of the fish species. If extensive farming is carried out, it is necessary to determine according to the natural feed conditions of paddy fields, weeds can be dominated by grass carp, accounting for 60%, carp 30%, and other fish 10%; general fertilizer paddy fields can be carp and carp, accounting for 60 %, grass carp 30%, other fish 10%; implement intensive culture, grass, wolfberry and equal weight accounted for 50%.
5, fish stocking operation should pay attention to matters
1) Adjust the water temperature: Because the paddy fields are shallow and the temperature of the water changes greatly, when the fish species are put in, first check whether the water temperature in the container for the transported fish species is the same as the temperature of the field water. The difference between the water temperature should not exceed 3°C. If the temperature difference is too large, it should be added to the container several times in the field, slowly making the water temperature basically the same. After the fish is adapted, gently put it into the field. If you use an oxygen bag to transport fish, you can put it in the field for about 1 hour, then unwrap it and put the fish into the field.
2) The timely injection of fresh water fish species is best placed in the inlet, found that the field of fertilizer or disinfectant has not completely disappeared, when the fish species are not adapted, they can inject new water in a timely manner to improve the survival rate of the species.
3) Disinfection of fish: Before the fish are put into the field, it must be sterilized by fish dipping. Place the fish in a 3-5% saline solution for 5-10 minutes, then sterilize and stock.
4) Check the fish-prevention facilities: Before restocking, check whether the field ridges, inlets and outlets, and fish-blocking facilities are intact. If any leaks are discovered, they should be blocked in time.
(II) Feeding Management
1. Feeding: Natural baits such as weeds, insects, plankton, and benthos in rice fields are available for feeding by fish. They can produce 10-20 kg of natural fish per acre, and must reach a yield of more than 50 kg per mu. Feeding measures. Commonly used species are tender grass, aquatic plants, duckweed, lettuce, cocoon, bran, and distiller's grains. Conditional feed pellet feed can be provided. Feeding should be fixed, timed, and quantified, and the amount of feeding should be adjusted according to feeding conditions. Generally, in the early feeding period, due to the natural food in the Tanaka, the fish body is also small, but it is not fed, and it is fed less in the medium term and then gradually increases. In the later period, as the temperature decreases, the food intake of the fish gradually decreases, when the water temperature drops below 10°C. , that is, stop feeding. In the Yangtze River catchment basin, from May to June, 1.5-2.5 kilograms of feed per acre per day, 8-12 kilograms of green material, and 3-5 kilograms of concentrate feed per acre per day, with green material 18-25 Kilograms gradually decrease after October. Green feeds should be tender and should be eaten on the same day.
2. Regulate the water level and water quality: According to the needs of rice and fish, the water in the rice fields should be well managed to adjust the water level and water quality. During the rice growing period, according to the requirements of rice cultivation technology, during the water release period, the fish grow in the earthworm without being affected. After the rice is pumped, the field water can be gradually deepened and the water level can be increased as much as possible. When the water quality of rice fields is acidic, it is unfavorable for fish growth. Especially after rice is harvested, piles of rice roots are rotted and seriously affect water quality. Therefore, it is necessary to keep as few as possible piles of rice, apply lime regularly to the field hoe, and adjust the water quality to be slightly alkaline.
3, prevention and treatment of fish diseases: prevention should be the main combination of prevention and treatment. Specific can take the following measures:
1) Paddy Field Disinfection: Before the fish is released, drugs should be used to disinfect. Commonly used lime and bleaching powders are used. The use of 25-40 kilograms of quick lime per acre will not only kill harmful bacteria and fierce fish, such as grasshoppers and green mud mosses, but also neutralize acidity, improve soil quality, and have effects on rice fish. benefit. Lime treatment The latter can be put into fry for about 7 days. Each acre contains 3 kg of bleachable powder containing 30% of available chlorine. After dissolving the water, it is poured into the whole field. Immediately afterwards, Putian is injected into clean water for 1-2 days, and fish fry can be added within 3-5 days.
2) Disinfection of fingerlings: Before the fingerlings are released, they must be disinfected. The commonly used drugs include 3% saline, 8.0 mg/kg copper sulfate, 10 mg/kg bleach solution, and 20 mg/kg potassium permanganate solution. The bleaching powder is mixed with the copper sulfate solution and has a good killing effect on most of the fish body parasites and germs. Bath time: According to the temperature, the number of fish, usually 10-15 minutes. When bathing, be sure to watch the fish activity.
3) Disinfection of bait: The bait should be disinfected before feeding. Animal foods, such as snails and clams, are washed with fresh water and selected for fresh feeding. Vegetable diets, such as aquatic grasses and phytotypes, were soaked for 20-30 minutes with 6.0 mg/kg bleach solution. When applying fermented manure, add 120 grams of bleaching powder to every 500 kilograms of manure and mix well and put it into the pool.
4) Disinfection of food counters, ditch and pits: When fish diseases are endemic, drugs should be disinfected on food counters, fish ditch and fish pits. Methods as below:
A. Bleaching powder hanging bag: Put a few bamboo sticks on the fish pit, hang 2-3 medicine bags for each fish hole, and put 50 grams of bleaching powder in it. Change dressing once every 3 days for 3 consecutive times.
B. Spill the drugs into fish ditch and fish pits, usually bleaching powder, trichlorfon or quicklime. For example, the pit area accounts for 12-15% of the paddy field area, bleaching powder 250 grams per acre or 90% crystal trichlorfon 3-5 grams (2.5% powder trichlorfon 30-50 grams). The trichlorfon to the ringworm, Three generations of insects and leeches have good control effects. Lime 1-2 kilograms per acre, after pouring water can prevent fish gills and other diseases.
C. Prevent natural enemies such as aquatic insects, frogs, water snakes, fish-eating birds, and rodents. Aquatic insects include otters and snails. The mink is extremely fierce, bulimia, and a small beak can pinch up as many as 16 fish fry overnight, causing the greatest damage to the fish. Before the fish is put, splash the whole field with lime and kill the otters. Trichlorfon powder can also be sprinkled on the surface of the water to form a concentration of 1.0-3.0 mg/kg, which effectively kills the leeches. Water snakes, birds, and rodents are all major natural enemies of fish.
D. Other oxygen-depleted floating heads: When the water is shallow, the stocking density is high, the feed is put in too much or the weather is hot and the humus decomposition accelerates, and the oxygen is consumed in large quantities, the dissolved oxygen in the water drops significantly, especially in the middle of the night, it can be reduced to The minimum is 0.2-0.9 mg/L. At this time, the fish will completely float due to lack of oxygen. If it is not rescued in time, there is a risk of death. Therefore, as the fish gradually grows, the consumption of dissolved oxygen in the water increases. According to water quality and fish activity conditions, clean water should be added in time to raise the water level of rice fields and improve water quality. When the weather is hot or the weather changes suddenly and the temperature is too low, you have to stop feeding. Found that the floating head should immediately discharge the field water and introduce high-oxygen water.
(3) Over-exploitation of harmful algae: During the high-temperature season in July and August, some of the red pods have died. At this time, algae in the rice fields will multiply. There is a type of Microcystis that has a layer of glial membranes outside the cells, which cannot be digested by the fish. After the death of the algae, the decomposition of the algal protein produces toxic substances (hydrogen sulfide, hydroxylamine) that are detrimental to the growth of the fish. According to the analysis, if one kilogram of water contains about 500,000 microcystis, the salmon fry can be killed. If more than 1 million fish are killed, most of the fish will die. PH value of 8-9.5, the water temperature 28-30 °C, the fastest reproduction of Microcystis, 0.7 mg per kg of copper sulfate can be sprinkled evenly in the field to kill.
Rice-field fish farming refers to a form of production in which paddy field's shallow water environment is used in conjunction with human intervention to grow rice and raise fish to increase production efficiency per unit area of ​​paddy field. Rice-field fish farming combines organic farming and planting, and rice and fish coexist and benefit each other, so that the ecosystem of rice fields can be rationally transformed both structurally and functionally, so as to maximize the "loading power" of rice fields.
The purpose of fish farming in rice paddies is to make full use of all biological and non-biological resources in the paddy fields to convert them into rice and fish, in order to increase the economic, ecological and social benefits of paddy field production. The combination of rice and fish is conducive to improving the structure and function of farmland ecosystems. The main benefits are the following four points:
First of all, paddy field fish can promote rice production. Rice-field fish farming is a kind of connotation expansion and reproduction, which is the reuse of land and resources. It can produce aquatic products without additional occupation of cultivated land. Experiences from various regions have shown that the development of fish farming in paddy fields will not only affect rice yield but also increase rice production. Rice paddies generally increase rice yield by 5%–10%, with higher yields by 14–24%.
Second, paddy fish farming can increase the supply of aquatic products to the community and enrich people's "vegetable baskets." In recent years in Jiangsu, Sichuan, Guizhou and other places, paddy field fish farming has become one of the main ways of local aquaculture. Rice field fish farming can be listed on a balanced basis, which plays an important role in stabilizing the supply of aquatic products, stabilizing market prices, meeting the needs of “vegetable baskets†and improving people’s dietary structure. Especially in areas where water resources are lacking and where traffic is congested, fish farming in paddy fields, local production, and local sales effectively solve the long-term problem of “difficulties in eating fish†in these areas.
Third, paddy fish farming can significantly increase farmers' income. Rice field fish increase both grain and fish, and it can make less fertilizer and less sprinkling of pesticides in paddy fields, save labor, increase income and reduce expenditures. In general, fish farmers can increase their income by 220 yuan per mu. High-standard rice-fish farming projects can raise fish in paddy fields by 350 yuan per mu. Using paddy fields to cultivate famous special aquatic products and carrying out rice-fish-mushroom triple compound breeding, the rice field per mu can increase more than 1,000 yuan.
Fourth, fish farming in rice fields has promoted the optimization of the ecological environment and enhanced its ability to resist natural disasters. Due to fish farming in paddy fields, the height of field ridges will be increased accordingly, and ravines will be excavated, which will greatly increase water storage capacity and will help prevent floods and droughts. In some hilly regions, the implementation of rice-fish farming projects can increase water storage capacity by 200 cubic meters per mu, which greatly enhances drought resistance. For some drought-ridden areas, the paddy fields with fish farming can effectively delay the drought due to the large water storage capacity. The effect of fish farming in paddy fields on the improvement of the environment is mainly manifested by its relatively effective disinfestation effect. According to the test, the density of rice larvae in fish farming is 80% lower than that in non-fish farms. The main reason is that fish raised in paddy fields consume large amounts of mosquito larvae and snails, which can raise the incidence of serious diseases such as malaria, filariasis, and schistosomiasis.
Second, what matters should be paid attention to in the rice field fish breeding construction?
(1) Selection of fish farm plots Any plots with sufficient water sources, good water quality, strong water retention capacity, convenient drainage and irrigation, irrepressible drought, and flash floods can all be used for fish rearing. In particular, in mountainous areas, it is necessary to choose those rice fields that have guaranteed water sources, are full of sunlight, and are not washed by floods. Shaditian should not adopt the “Tianyu†method to submerge irrigated paddy fields and cold-water immersed fields.
(II) Construction of Field Projects
1. There is less investment in general field projects for general rice field fishery field construction. Farmers use the idle season to invest and dig for fish and fish ditch. Its engineering features are: using earth to increase, strengthening, and widening field rakes, the fish ditch fish need to be excavated every year.
(1) Fish gills account for 5-8% of the total land area. One or two acres of plots will be dug, one or three or more acres of rice paddies may be excavated 2-3, and the fishing rods are mostly built in the middle of the field or on the side of the field, excavating a square or round fishing rod, with a depth of 1-1.2 meters. The fish ditch center groove communicates with each other. The excavation time can be 30-40 days before transplanting. After the excavation, it should be sorted every 10 days, and the fish should be finished 3-4 times.
(2) The fish ditch is excavated when the seedlings turn green after transplanting, and the seedlings can be transplanted on the edge of the fish ditch. The area of ​​the fish ditch is 3-5% of the total area, the width of the ditch is 40 cm, and the ditch is 50 cm deep. The shape of the fish ditch can be dug into "10", "day", "tian", or "well" shapes according to the size of the paddy fields, and be connected to the fishing rods. Can be finished twice in the field and heading.
(3) Raise the height of the field and remove the soil from the digger to increase the height of the field. Normally, the earthworms should be raised to about 40 cm, widened by more than 50 cm, and hammered firmly to prevent fish from escaping or flooding during heavy rains.
(4) Each of the built-in intakes and drainage outlets shall be provided with one inlet and one for water outlet, and the other one shall be provided with one or three overflow gaps according to the size of the plots. The inlet and outlet openings are generally open at opposite corners of the paddy field, and the inlet and outlet openings are determined according to the amount of rice paddy drainage. The water intake is about 10 cm higher than the field surface, and the water outlet should be parallel or slightly lower than the field surface. In the terraces of hilly and mountainous regions, the drainage of the upper field is often the inlet of the next field, and the series connection is adopted. The paddy fields in the plain area are mostly drained and drained, and the water conservancy facilities are relatively complete. Some of them are the same as those in the hilly areas.
(5) The rice paddy fields and drainage ports installed on the barrages should be installed on the corresponding two corners of the field to make the water flow clear. Note: Drain outlets should be solid and firm. Bars should be installed to prevent fish escape and miscellaneous fish from entering the fish-raising paddy fields. Bars can generally be made of bamboo or wire braided into a mesh shape, the size of which is based on the size of the fish. The barrage is 30 cm wider than the inlet and outlet, and the upper end of the barrage is more than 10-20 cm. The lower part is embedded in the lower clay soil 30 cm.
2. The permanent field project of the permanent paddy field fishery field project requires the use of bars, slabs, cement prefabricated plates or bricks to reinforce the field rakes, fishing rods and inlets and outlets. Tian Hao high, ditch width, ditch depth, and large. Gullies account for 8%-15% of the total area. This kind of project is of good quality and has a long service life. It only needs to excavate and tidy the fish ditch every year, and it is not necessary to build ridges and fish gills.
(1) The fishing rod (fish slip) is actually a small pond, which accounts for 6-8% of the total area and 1.5-2.5 meters deep. The fishing rod is generally located at the side of the field or in the middle of the field. Avoid selection at Tianjiao and often passing pedestrians. Tian field. Rod shape is oval, square or rectangular. The fishing rods are best dug into a two-step downhill type, that is, the excavation is made at a slope ratio of 1:0.5 at the upper 1 meter, and the lower part is excavated at a slope ratio of 1:1, leaving a 30 cm wide platform between the two parts. . Slope protection with slate, bar, brick or cement prefabricated panels. In order to prevent silt from entering the gills, a 20 cm high and 30 cm wide grate should be built on the edge of the gutter. The number of fishponds built depends on the size of the plots, generally 1-2 acres of rice fields will be built, and 3-5 acres of rice fields will need to be built. Each area will be 50-100 square meters. The fish larvae built in the center of the field generally need to open 4 gaps, and the gap in the fish larvae is mainly connected with the fish ditch. The purpose of the surimi is to apply chemical fertilizers, pesticides, weeding, and sun drying; the fish can temporarily gather in the cocoon; in summer when the water temperature is high, the fish can avoid the heat in the surimi; when the drought occurs, the fish can gather in the trough, Living in the middle of life, normal growth. The bait station can be set in the fish larvae, and the bait can be put on the bait station set in the urn to check the fish's feeding and activity.
(2) The fish ditch is set in the fish ditch rice field and should be determined based on the size of the plot and the shape of the field. Generally account for 3-5% of the total field area, excavated into a "1" shape, "10" shape, "Japanese" shape, "Tian" shape, "encirclement" shape and so on. The ditch is 0.8-1m wide and 0.5-0.7m deep. Center fish ditch: Shunchang Tianbian, open a ditch in the center of the field; around the fish ditch: 1.5 meters away from the field to excavation. Each year should be excavated 20-30 days before planting, 5-7 days before planting, and then finishing 1-3 times, deep foot field, soaking fields, to be more 2-3 times, the fish ditch was formed. (The rice fields in the ditch are no longer dug trenches).
(3) Heightening, widening, and strengthening of the construction of Tianshui Tianyu can be carried out simultaneously or before the construction of fishing rods, followed by construction of Tianshao. Tian Hao is 1-1.2 meters high and the dome is 0.6-0.8 meters wide. After the first stone or cement board or brick and cement is used to harden, the dry earth in the former Tiantian will be filled with cracks. Tian Hao used a piece of stone to build one intake and one drain, and to maintain multiple levels of water level and flood discharge. The water level should be kept above 0.3 meters (200 cubic meters per mu), and fish traps should be installed in front of the drainage outlets.
(4) Intake and drainage systems and the installation of fish and fishery facilities The construction of the intake and drainage systems shall determine the width, depth and depth of the drainage channels (channels) according to the size of the rainwater harvested in the rice fields. Generally, paddy fields are formed and upstream water sources are guaranteed. Inlets and drains should be slightly wider and deeper. Intake and drainage systems should be built outside the field and cannot be connected in series in rice fields. The inlet and outlet openings should be in the field ridges that are relatively two-cornered in the paddy field, which can make the entire rice field flow smoothly. The size of the outlet should be determined according to the size of the field and the amount of water entering the storm. The inlet should be about 10 centimeters higher than the field surface, the outlet should be flat or slightly lower, and the general outlet width should be 1-1.5 meters. Prefabricated with strips of stone or cement, it will not collapse. The drain outlet shall be installed with two layers of bamboo foil or barbed wire so that it can be curved and inserted into the field using bamboo rods or steel bars. The two curved bamboo foils are about 0.5 meters apart, and they are denser than the one layer of the outlet to ensure that the fish species do not escape. The length of fish bamboo foil is 3 times that of the outlet. The second layer of bamboo foil is relatively thin and is mainly used to prevent debris from blocking the first layer of bamboo foil so as to ensure the smooth flow of drainage outlets. The length of the bamboo foil used for blocking debris is more than four times that of the drainage outlet. The upper end of the bamboo foil should be It is 0.5 meters higher than Tiantian and the lower end is better than 30 cm below hard mud. The water inlet should also be covered with a layer of bamboo foil to prevent the fish from escaping. It is also arc-shaped and the length is 2 times the inlet.
Third, what are the feeding and management techniques for paddy field fish breeding?
(I) Techniques for cultivation of fingerlings in paddy fields
1. Preparation of fry before stocking
1) Disinfection and water injection. Before the excavation of the fish ditch in the open car, the water in the field and the pupa is 6-10 cm, and 60-75 kg of lime are used per acre to disinfect the lime. The lime is added to dissolve water, and the lime is poured evenly into the fields and the pupa without cooling. In order to improve the effect, the next day Tweezers and other tools can be used to shake the muddy mud and muddy bottom, so that the lime mud can be fully mixed with the mud. After disinfection for 8-10 days, all vaccines can be released after the efficacy disappears. The depth of the fish is kept at 1/3 of the depth of the pool when the fish is in the pool.
2) Fertilizer water quality. Before the paddy field is put in fry, Tianshui should have a certain amount of fat. It is necessary to cast basal fertilizer before stocking, so that the "fat pool underwater" allows the fish to obtain a lot of high-quality palatable natural foods in order to speed up growth and improve survival. rate.
The young fish in the first lower pool swallows palatable zooplankton such as rotifers. According to experiments, 10,000 fish per liter of rotifers in the lower larvae of the fry, biomass is 20-40 mg/l. After fertilizing seedlings, bacteria and phytoplankton multiply first, followed by protozoa, rotifers, small horns, large branches and copepods. Therefore, the key problem in submerged ponds is to master basal fertilisers. In the time when the fish fry down the pond, it is the peak of rotifer breeding.
The time and amount of base fertilizer should vary depending on the type of fertilizer, the conditions of the pond, and the type of fry. The peak time of plankton after fertilization is also not the same. When the water temperature is above 20°C, the zooplankton can reach its peak in 4-7 days. The application of decomposed manure can be carried out 4-5 days before the fry drop. 120 kg per acre field, diluted with water, Quanchiposa. The application of big grass (green manure) should be carried out in the lower pool for 5-10 days, and 200 kg per mu. The big grass can be piled in a shallow place about 1 meter away from the side of the planter, allowing it to rot and decompose naturally, turning the grass in a few days. Fertilizer spreads into the water. After the leaves and stalks are rotted, the root residue will be removed. It should be noted that if the basal fertiliser is too early and the peak period of rotifers has passed, a large number of horny horns, especially large horny horns, will appear. Instead, they will compete with the saplings for oxygen and fight for space; if the fertilization is too late, there will be insufficient rotifers. The lack of palatable baits in the lower pool of fry will greatly affect the survival rate of fry.
2. Problems to be noticed by the fish fry in Shimoda (1) The temperature of the fry before being placed in the field cannot be too different from the temperature of the paddy field. If the temperature difference exceeds 5°C, the water temperature in the container must be gradually adjusted with Tanaka water. When the water temperature in the container is basically the same as the water temperature in the field, the fry can be put into the field. Otherwise, fry will have a "cold", and severe cases will cause massive deaths.
(2) Artificially propagated fry must be inflated, can swim flat, and can only eat the outside food before going to the pool (4-5 days after hatching). The pool is too early, the fish swimming ability is weak, the body is tender, and it is easy to cause death.
(3) It is necessary to wait until the medicinal properties of the Qingchi medicine have completely disappeared, otherwise the fish will be killed in large numbers.
(4) Check whether any enemy organisms are left in the pond. Before clearing the pond until the fry is released, the fry eggs may have frog eggs, cockroaches, aquatic insects, and residual wild fish. When necessary, fish fry nets should be used for 1-2 times to remove these predators.
(5) Fish fry and fingerlings should not be replaced with well water during transportation. Because the first temperature of the well water is low, the temperature difference between the water in the container and the seedling is large; the second is that the oxygen content is small; the third is the specific gravity, which can easily cause the uneven temperature of the water in the container; and the fourth is that the well water is alkaline or acidic. Stronger.
3, stocking (1) varieties of grass carp, carp, carp, tilapia, carp, carp, bream, carp, loach, Macrobrachium rosenbergii, shrimp and other varieties.
The stocking time is the traditional stocking method, and the stocking time is usually about 5 days after the rice is planted. After the seedlings return to green, the fry is directly placed in the paddy field. Nowadays, high-yielding fishery rice fields are excavated with larger fish gills. In order to prolong the growth period of fish, it is required that the fish be irrigated in the early spring season, and then put in the fish gills for raising. Put the fish into the field.
(2) Stocking density of fry The fry are directly cultivated to summer flowers, and the general stocking density is about 10,000 per mu. If it is a breeding ground for Oda and Sakamoto, due to shallow water, the stocking density can be 4-50000 watercress per acre. If the fish fry are first raised to black larvae fry, and then divided into pools, the general mu stocking density of 160,000; and then from Wuzi to 5 cm species of fish, the general mu stocking for 2-3 million. Reasonable stocking is the key to raising the survival rate of fry breeding, and at the same time, it also saves feed, fertilizer and manpower. The stocking density and the conditions of the cultivation pond, the quantity and quality of the feed and the fertilizer, the sooner or later of the stocking time, and the level of the breeding technique are closely related. In places with good conditions, the stocking density can be greater; otherwise, the stocking amount should be smaller.
4. Feeding management of fry fingerlings
1) Feeding and Fertilizing Feeding: Weeds, benthos, zooplankton, and rice pests in paddy fields can provide certain feed for fish. However, in order to obtain higher fish yields in paddy fields, it is not enough to rely on the food organisms in the field. It is necessary to feed the appropriate amount of feed like pond fish. Feeding should be implemented "three set": timing, quantitative, positioning. To acclimate the fish to concentrate in the potholes in the rice paddies, you can take a table in the fish pot and take the fish to the table to feed. Feeding amount depends on the size and quantity of the fish species. In the first few days after the release of the spray, the milk was fed once every afternoon and in the afternoon. The dosage was about 0.20 kg per 10,000 tails. When the fry were grown to 1.5-2 cm, they were fed with a certain amount of wheat flour and dried food. On the split, feed it twice in the afternoon. After a length of 3 cm, grass carp and quail species can be cast with 1-1.5 mm diameter pelleted feed and fine green duckweed and rice bran. On sunny days, the depth of the water is strong, and the fish can be fed more. In cloudy days, it is hot and shallow, and less feeding is required. The feeds fed will soon be eaten, and the amount of feeds will be increased on the second day; fish will not eat fast and there will even be residual baits, and feed intake should be reduced appropriately.
Fertilization: timely fertilization in paddy fields, can be used as rice fertilizer, but also for the omnivorous fish to provide some food. In principle, the fertilization is a small amount, many times, to keep the water color of the fish is often green, blue and green, usually 1 fermentation per acre fertilization farmyard fertilizer 25-30 kg.
2) Day-to-day management: After the fish is put in paddy fields, special management should be carried out so that it can be managed after it is released. For stocking fish before transplanting, the fish shall be returned to the pits and raised during the transplanting period. After the seedlings have returned to the green, they are allowed to swim back to the fields. Daily management should insist on morning and evening inspections of the fields. In the early morning, observe whether the fish has floating heads or become sick. In the evening, check the fish’s diet. Found fish floating head, should be filled with fresh water, it is best to live water string irrigation, in order to increase dissolved oxygen in water. Pay attention to checking whether there is a rat hole, collapse, leakage, etc. in the field. Frequently dredge the fish gills and fish ditch to prevent blockage of the mud, timely eradicate the weeds in the potholes, and remove the residual baits in the potholes. The spring plowing and transplanting, and the summer harvest to prevent the Tianzhong mud back into the pit. During the high temperature season, it is necessary to put a shady shade on the side of the fish pit and raft, and appropriately deepen the water level in the paddy fields so as to prevent the fish from becoming uncomfortable because the water is too shallow and the water temperature is too high. Always check the entrance and exit of fish to prevent fish from escaping.
3) Capture: Fishing before and after rice harvest, enough for the sale of the product specifications, not enough to transfer the product specifications to other waters. Where conditions permit, irrigation of deepwater intensive culture can be continued after rice is harvested and harvested until the end of winter and early spring to implement full-scale fish farming. This allows for higher yields and benefits.
When starting the fish, first dredge the ditch around the ditch and the main groove in the field, and then slowly drain the fish. The fish naturally concentrate in the gills, and then use a dip net or a net bag to fish. When capturing, the operation must be careful, careful not to hurt the fish body. Such as catching fish species, should be promptly placed in clean water or running water cages, so that it spit up the mouth and the mud in the mud, temporarily raised for one day, after disinfection and then transferred to the field, transferred to continue feeding.
In places where conditions permit, in order to increase fish production, round robin can be implemented. Usually, the fish that meets the specifications of the product will be caught and listed, and the fish species will be properly added according to the density of the fish.
What are the techniques for raising fish in paddy fields?
(i) Fish stocking
1. Stocking species: In the past, paddy fish farming was only a few species such as carp, carp, and grass carp. It has now been developed to stocking tilapia, carp, carp, carp, carp, river crab, loach, macrobrachium rosenbergii, and green Shrimp and other varieties, but also the development of Ping, bamboo shoots, vegetables, edible fungi and other production for integrated breeding. Different regions can choose stocking species according to different circumstances. In principle, all species suitable for pond culture can be cultured in paddy fields.
2, stocking time: generally promote early release, fish species less than 3 cm, can be stocked before transplanting, because the small individual fish, will not tilt the seedlings. At this time, the paddy field where the basal fertilizer is applied has a large population of plankton and benthic animals after plowing, which is particularly advantageous for the growth of fry. Practice has proved that before and after transplanting into the same specifications of the species of fish, transplanting before feeding only more than 15 days after transplanting, but the field when the individual than after transplanting into the increase of more than 100 grams. For fish species 6-10 cm, it is best to wait until the seedlings turn green before putting them in. In the Yangtze River basin and South China, the use of paddy fields for fish rearing should be generally completed before the Spring Festival. Putting seeds before the Spring Festival, first, most of the fish in the adult fish field have been harvested; second, the fish's ability to move is weak, which facilitates fishing. The water temperature is low, and the scales of the fish are tight. In fishing and stocking operations, it is not easy to be injured, and the incidence and mortality during feeding can be reduced; the third is early restocking to extend the growth period. The stocking of fish should be carried out on a sunny day, and the weather in cold and snow can not be stocked to prevent the fish from being frosted during fishing operations and transportation.
3, stocking methods: winter and spring farming season, excavation of a good fishing rod, fish pit. For paddy fields where the fish were raised last year, it is better to refit the fishing rods, fish pits, etc. to remove the weeds. Before stocking, drain pits, rakes, and expose them to the sun for a week or so, and then pour about 10 centimeters deep, disinfect them with quick lime, and apply 50 kg of quick lime. After another week, fill enough water to fertilize 300 kilograms per acre to properly fertilize water. After 4-5 days, fish species can be released for feeding. Stocking species requires a healthy body, no disease and no injury, and the specifications of the same batch of fish should be neat. Before stocking, the fish should be disinfected with a fish bath.
4, stocking number: According to the size of the fish to determine the number of fish stocking. Paddy field cultured adult fish, promote the stocking of large-sized fish species, generally about 8 to 15 centimeters of large-sized fish species per acre of rice fields, about 8 to 15 centimeters of large-sized fish species per acre of high-yielding fish and rice fields. 800 tails. The specific amount of stocking should be adjusted according to local conditions, and it should be appropriately increased or decreased according to the ecological conditions of the paddy fields, the production requirements and the size of the fish species. If extensive farming is carried out, it is necessary to determine according to the natural feed conditions of paddy fields, weeds can be dominated by grass carp, accounting for 60%, carp 30%, and other fish 10%; general fertilizer paddy fields can be carp and carp, accounting for 60 %, grass carp 30%, other fish 10%; implement intensive culture, grass, wolfberry and equal weight accounted for 50%.
5, fish stocking operation should pay attention to matters
1) Adjust the water temperature: Because the paddy fields are shallow and the temperature of the water changes greatly, when the fish species are put in, first check whether the water temperature in the container for the transported fish species is the same as the temperature of the field water. The difference between the water temperature should not exceed 3°C. If the temperature difference is too large, it should be added to the container several times in the field, slowly making the water temperature basically the same. After the fish is adapted, gently put it into the field. If you use an oxygen bag to transport fish, you can put it in the field for about 1 hour, then unwrap it and put the fish into the field.
2) The timely injection of fresh water fish species is best placed in the inlet, found that the field of fertilizer or disinfectant has not completely disappeared, when the fish species are not adapted, they can inject new water in a timely manner to improve the survival rate of the species.
3) Disinfection of fish: Before the fish are put into the field, it must be sterilized by fish dipping. Place the fish in a 3-5% saline solution for 5-10 minutes, then sterilize and stock.
4) Check the fish-prevention facilities: Before restocking, check whether the field ridges, inlets and outlets, and fish-blocking facilities are intact. If any leaks are discovered, they should be blocked in time.
(II) Feeding Management
1. Feeding: Natural baits such as weeds, insects, plankton, and benthos in rice fields are available for feeding by fish. They can produce 10-20 kg of natural fish per acre, and must reach a yield of more than 50 kg per mu. Feeding measures. Commonly used species are tender grass, aquatic plants, duckweed, lettuce, cocoon, bran, and distiller's grains. Conditional feed pellet feed can be provided. Feeding should be fixed, timed, and quantified, and the amount of feeding should be adjusted according to feeding conditions. Generally, in the early feeding period, due to the natural food in the Tanaka, the fish body is also small, but it is not fed, and it is fed less in the medium term and then gradually increases. In the later period, as the temperature decreases, the food intake of the fish gradually decreases, when the water temperature drops below 10°C. , that is, stop feeding. In the Yangtze River catchment basin, from May to June, 1.5-2.5 kilograms of feed per acre per day, 8-12 kilograms of green material, and 3-5 kilograms of concentrate feed per acre per day, with green material 18-25 Kilograms gradually decrease after October. Green feeds should be tender and should be eaten on the same day.
2. Regulate the water level and water quality: According to the needs of rice and fish, the water in the rice fields should be well managed to adjust the water level and water quality. During the rice growing period, according to the requirements of rice cultivation technology, during the water release period, the fish grow in the earthworm without being affected. After the rice is pumped, the field water can be gradually deepened and the water level can be increased as much as possible. When the water quality of rice fields is acidic, it is unfavorable for fish growth. Especially after rice is harvested, piles of rice roots are rotted and seriously affect water quality. Therefore, it is necessary to keep as few as possible piles of rice, apply lime regularly to the field hoe, and adjust the water quality to be slightly alkaline.
3, prevention and treatment of fish diseases: prevention should be the main combination of prevention and treatment. Specific can take the following measures:
1) Paddy Field Disinfection: Before the fish is released, drugs should be used to disinfect. Commonly used lime and bleaching powders are used. The use of 25-40 kilograms of quick lime per acre will not only kill harmful bacteria and fierce fish, such as grasshoppers and green mud mosses, but also neutralize acidity, improve soil quality, and have effects on rice fish. benefit. Lime treatment The latter can be put into fry for about 7 days. Each acre contains 3 kg of bleachable powder containing 30% of available chlorine. After dissolving the water, it is poured into the whole field. Immediately afterwards, Putian is injected into clean water for 1-2 days, and fish fry can be added within 3-5 days.
2) Disinfection of fingerlings: Before the fingerlings are released, they must be disinfected. The commonly used drugs include 3% saline, 8.0 mg/kg copper sulfate, 10 mg/kg bleach solution, and 20 mg/kg potassium permanganate solution. The bleaching powder is mixed with the copper sulfate solution and has a good killing effect on most of the fish body parasites and germs. Bath time: According to the temperature, the number of fish, usually 10-15 minutes. When bathing, be sure to watch the fish activity.
3) Disinfection of bait: The bait should be disinfected before feeding. Animal foods, such as snails and clams, are washed with fresh water and selected for fresh feeding. Vegetable diets, such as aquatic grasses and phytotypes, were soaked for 20-30 minutes with 6.0 mg/kg bleach solution. When applying fermented manure, add 120 grams of bleaching powder to every 500 kilograms of manure and mix well and put it into the pool.
4) Disinfection of food counters, ditch and pits: When fish diseases are endemic, drugs should be disinfected on food counters, fish ditch and fish pits. Methods as below:
A. Bleaching powder hanging bag: Put a few bamboo sticks on the fish pit, hang 2-3 medicine bags for each fish hole, and put 50 grams of bleaching powder in it. Change dressing once every 3 days for 3 consecutive times.
B. Spill the drugs into fish ditch and fish pits, usually bleaching powder, trichlorfon or quicklime. For example, the pit area accounts for 12-15% of the paddy field area, bleaching powder 250 grams per acre or 90% crystal trichlorfon 3-5 grams (2.5% powder trichlorfon 30-50 grams). The trichlorfon to the ringworm, Three generations of insects and leeches have good control effects. Lime 1-2 kilograms per acre, after pouring water can prevent fish gills and other diseases.
C. Prevent natural enemies such as aquatic insects, frogs, water snakes, fish-eating birds, and rodents. Aquatic insects include otters and snails. The mink is extremely fierce, bulimia, and a small beak can pinch up as many as 16 fish fry overnight, causing the greatest damage to the fish. Before the fish is put, splash the whole field with lime and kill the otters. Trichlorfon powder can also be sprinkled on the surface of the water to form a concentration of 1.0-3.0 mg/kg, which effectively kills the leeches. Water snakes, birds, and rodents are all major natural enemies of fish.
D. Other oxygen-depleted floating heads: When the water is shallow, the stocking density is high, the feed is put in too much or the weather is hot and the humus decomposition accelerates, and the oxygen is consumed in large quantities, the dissolved oxygen in the water drops significantly, especially in the middle of the night, it can be reduced to The minimum is 0.2-0.9 mg/L. At this time, the fish will completely float due to lack of oxygen. If it is not rescued in time, there is a risk of death. Therefore, as the fish gradually grows, the consumption of dissolved oxygen in the water increases. According to water quality and fish activity conditions, clean water should be added in time to raise the water level of rice fields and improve water quality. When the weather is hot or the weather changes suddenly and the temperature is too low, you have to stop feeding. Found that the floating head should immediately discharge the field water and introduce high-oxygen water.
(3) Over-exploitation of harmful algae: During the high-temperature season in July and August, some of the red pods have died. At this time, algae in the rice fields will multiply. There is a type of Microcystis that has a layer of glial membranes outside the cells, which cannot be digested by the fish. After the death of the algae, the decomposition of the algal protein produces toxic substances (hydrogen sulfide, hydroxylamine) that are detrimental to the growth of the fish. According to the analysis, if one kilogram of water contains about 500,000 microcystis, the salmon fry can be killed. If more than 1 million fish are killed, most of the fish will die. PH value of 8-9.5, the water temperature 28-30 °C, the fastest reproduction of Microcystis, 0.7 mg per kg of copper sulfate can be sprinkled evenly in the field to kill.
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