CATDOLL : CATDOLL: Who knows the technique of raising shrimp in rice fields?

Shrimp farming in rice fields is a breeding technology that allows animals and plants to coexist in the same environment and benefit the ecology. It uses the water space formed during the irrigation of rice fields and the natural food in it to feed shrimps. It is economically reasonable, reduces field pests, reduces the amount of fertilizer used in rice fields, and increases the output value of breeding. It is a way to develop ecological agriculture to prosper the rural economy and is one of the preferred projects for rural prosperity. The rice field shrimp farming technology is introduced as follows:

1. Conditions and basic facilities for shrimp farming in rice fields

1. Rice field selection: Rice fields for shrimp farming require selection close to water sources, with abundant water and good water quality.

It is pollution-free, easy to drain and irrigate, and uses clay loam that is not easy to leak water. The area for shrimp farming in rice fields is generally about ten acres, and the fields are rectangular.

2 Field facilities:

A. Widen and raise the embankment: When choosing rice fields for shrimp farming, the embankment must be widened and raised to facilitate raising the water level and prevent water leakage and crossing the embankment. The top width of the embankment is 2 meters, with a slope of 1:1-1.5. The embankment should be 0.8-1 meter higher than the rice field to increase the water level after the shrimp and rice are harvested and raise shrimp for another season. A small embankment with a width of 30 cm and a height of 20 cm is built between the rice field and the ring ditch to separate the ditch from the rice field, which is conducive to shrimp farming in the ditch and rice field management in the early stage.

B. Trenching: The size of the ring ditch depends on the size of the field. Generally, the ditch area accounts for 20-30%, the ditch width is 4-6 meters, and the ditch depth is 1 meter. Several field ditches with a width of 0.3 meters and a depth of 0.2 meters are dug in the field to connect with the ring ditch. When ditching, leave a mechanical passage.

C. Drainage and inlet system: It is best to open the drainage and irrigation outlets on the ridges at the two opposite corners of the rice field so that all the water can flow, which is conducive to the growth of shrimps. A mesh fence should be installed at the drainage point to prevent the shrimps from escaping, and a sand silk net with a mesh size of 60 or more should be connected to the water inlet to prevent wild fish from entering.

3 Temporary rearing of shrimp fry: In order to prolong the growth period of swamp shrimp, the purchased swamp shrimp fry need to be temporarily reared so that their size reaches 2-3 cm and the survival rate is improved.

4. Preparation before rice field stocking:

A. Disinfection of the ring ditch: 10-15 days before stocking shrimp fry, disinfect the ring ditch with 15 kg of bleaching powder or 100 kg of quicklime per acre to kill harmful organisms and bacteria in the ditch.

B. Add bait into the water: Add 60 cm of water one week after disinfection, and apply 3-5 dan of base fertilizer per mu (circumferential ditch area) to cultivate fertile water. On the one hand, it can provide abundant natural bait for shrimps after entering the ditch; on the other hand, it can prevent the reproduction of harmful algae.

C. Water testing: Before stocking shrimp fry, test the physical and chemical indicators of the ditch water, or place a net cage in the ditch and put a few shrimp fry in the cage to observe their activities and eating habits. If they are normal, you can stock the fry.

2. Methods and management of shrimp farming in rice fields:

1. Shrimp fry stocking:

A. Time: In Shanghai area, large-sized temporary seedlings can be released in mid-May, while diluted seedlings should be released around May 20.

B. Density: In paddy fields where the ditch area accounts for 20%, 10,000 temporary seedlings of 2-3 cm in diameter are stocked per mu, and 15,000 diluted seedlings per mu are stocked. If the area of ​​the ditch is increased, the stocking density will be increased.

C. Precautions when stocking: The water temperature must not be lower than 18°C ​​when stocking, the temperature difference between the water temperature in the temporary holding pond and the ring ditch must not be greater than 2°C, and the small ridge between the ring ditch and the field should be well built to prevent the shrimp fry from entering the field.

2. Feeding: At present, Macrobrachium rosenbergii farming mainly uses compound feed, which is appropriately matched with animal feed. The crude protein content of the compound feed is 35% in the early stage and 30% in the middle and late stages.

A. Feeding time and frequency: Generally, the feeding frequency is once in the morning and once in the evening every day. As the shrimp grows bigger, it can be increased to three times, i.e. 6 a.m. and 6 p.m. (the feeding frequency is 6 a.m., 4 p.m. and 10 p.m.).

B. Determination of the number of baits to be cast:

(1) At the beginning, feed 250g to 500g of high-quality compound bait for every 10,000 shrimp fry per day. If there is abundant plankton in the water, less or no bait can be fed.

(2) Determine the amount of feed based on the estimated number of shrimps and their average body length. Feed 8% of the shrimp's body length before 5-6 cm and 5% after 7 cm.

(3) Adjust according to the eating situation. If the fish finish eating within 1 hour after feeding, the amount of feed should be increased. If there is any left before the next feeding, the amount of feed should be reduced.

(4) If the weather is hot and humid, the water is too rich, the shrimps are floating, or the shrimps are dragged out, the amount of feed should be reduced.

3. Management:

A. Water quality management: There is relatively less water in rice fields for shrimp farming, and the water level is shallow. Aerators are generally not installed, so the water quality should be kept fresh and lively during the breeding process, and not too rich.

(1) In the early stage (May-June), the water level should be 60-80 cm. The water quality should not be too thin. You can apply some compound fertilizer appropriately.

(2) Mid-term (July-August) The water temperature rises at this time, so the water level should be increased as much as possible, and the small embankment should be opened to allow the shrimp to enter the pen. In the hot season, new water should be added every 2-3 days. Usually, the water should be changed once a week, and 1/3-1/2 of the water should be changed each time.

(3) Late period (September-October) Shrimp can be gradually caught. Water changes should be coordinated with shrimp catching. Too little water change will produce black-shelled shrimp, while excessive water change will cause too many soft-shelled shrimp to die during fishing.

B.Daily Management:

(1) Carry out the determination of routine physical and chemical indicators, such as pH value, water temperature, ammonia nitrogen, etc.

(2) Pay attention to whether there is water leakage or shrimp escape from the gate and the net, and remove harmful organisms such as frog eggs in the ditch in a timely manner.

(3) Observe the activities and eating habits of the swamp shrimp, measure their body length and weight every 10 days and make records. Each observation should not be less than 50 shrimp.

(4) Observe the water quality at all times, especially when the weather is hot and humid, and pay attention to the floating heads and ponds of shrimp.

3. Rice Planting and Management

Rice planting is the same as conventional. Hybrid rice with good resistance to lodging and higher stems is selected. Sufficient base fertilizer is applied during the transplanting period. Digging and transplanting are started at the end of June. Topdressing can be done 1-2 times depending on the growth of rice, with about 15 kg of urea applied per mu each time. In the process of shrimp farming in rice fields, three key points should be grasped, namely scientific field drying, reasonable fertilization and safe use of drugs.

4. Harvest

(1) Harvesting of Macrobrachium

From September to October, swamp shrimp can be harvested and put on the market. The fishing methods include purse seine and digo net (shrimp trawling net). After the harvest, the pond is dry. During the shrimping period, the water level should be kept low, lower than the rice fields. In order to allow all the shrimp to enter the ring ditch, the water release speed should be slowed down as much as possible after a few hours, generally more than 3 hours. When purse seine and shrimp trawling, pay attention to muddy water, catch fast, catch large ones and keep small ones, and prevent floating shrimps and dead shrimps in the pond. Generally, all swamp shrimps should be caught in mid-October, otherwise the shrimps will be easily frozen to death due to the shallow water level in the ring ditch.

(2) Rice harvesting

Waterway harvesting can be carried out in early November. During the harvest period, the water in the ditch should be drained and the fields should be dried for more than half a month to facilitate mechanized operation.

5. Farming shrimp in winter ditch fields

In Shanghai, after the rice is harvested, a batch of freshwater shrimp is released until the end of April of the following year. After the rice is harvested, the fields are filled with water in time, and 20,000 to 30,000 large-sized freshwater shrimp are released per mu. In order to obtain high yields, the ridges are raised as high as possible and the water is deepened to increase the living space of the shrimp. The shrimp can be harvested on May 1 of the following year.

From September to October, swamp shrimp can be harvested and put on the market. The fishing methods include purse seine and digo net (shrimp trawling net). After the harvest, the pond is dry. During the shrimping period, the water level should be kept low, lower than the rice fields. In order to allow all the shrimp to enter the ring ditch, the water release speed should be slowed down as much as possible after a few hours, generally more than 3 hours. When purse seine and shrimp trawling, pay attention to muddy water, catch fast, catch large ones and keep small ones, and prevent floating shrimps and dead shrimps in the pond. Generally, all swamp shrimps should be caught in mid-October, otherwise the shrimps will be easily frozen to death due to the shallow water level in the ring ditch.

(2) Rice harvesting can be carried out in waterways in early November. During the harvesting period, the water in the ditches should be drained and the fields should be dried for more than half a month to facilitate mechanized operations.

5. Farming shrimp in winter ditch fields

In Shanghai, a batch of shrimps are released after the rice is harvested until the end of April of the following year. The fields are filled with water in time after the rice is harvested, and 20,000 to 30,000 large-sized shrimp seedlings are released per acre. In order to obtain high yields, the ridges are raised as much as possible and the water storage is deepened to increase the living space for the shrimps. The harvest can be made around May 1 of the following year.

1. Selection of rice fields for shrimp farming. Rice fields for shrimp farming should be selected in fields with convenient drainage, sufficient water sources, good water quality, and good water retention performance. If conditions permit, concentrated and continuous fields are better for easier management.

2. Field engineering for rice-shrimp symbiosis. A circular ditch or "田"-shaped field engineering should be excavated for shrimp-raising rice fields. The circular ditch engineering is to dig a circular shrimp ditch 2-3 meters wide and 0.5-1 meters deep along the ridges around the field. The ditch soil is added to the ridges around the field to prevent water leakage. The circular ditch should be 1-1.5 meters away from the ridges. At one end of the circular ditch, a 5-meter wide and 1.2-meter deep shrimp temporary pond should be dug. The "田"-shaped engineering is to dig a "+"-shaped shrimp ditch in the middle of the field while the ring is opened. This ditch is 2 meters wide and 0.5-0.7 meters deep, and is connected to the circular ditch. At the same time, each rice field must establish a water inlet and outlet system, and the water inlet must be filtered with a dense net to prevent wild fish from entering.

3. Timely planting and management of rice. Rice varieties should be selected with early-maturing single-season or single-season hybrid late rice varieties that have hard stems, strong fertilizer resistance, not easy to fall over, and strong disease resistance. Apply 20-30 dan of livestock and poultry manure per mu of paddy fields, then plow the fields with water, level the fields, and sprinkle 100 kg of quicklime or 1 kg of pond cleaning per mu. To kill loaches, eels and other pests in paddy fields. Before transplanting, apply 40 kg of ammonium carbonate and 30 kg of phosphate fertilizer per mu. In mid-June, seedling planting and rice production management will begin. It should be noted that when applying pesticides to rice, high-efficiency and low-toxic pesticides should be used as much as possible. It is forbidden to use trichlorfon and pyrethroid pesticides. The method of using pesticides is to spray them on the stems and leaves of rice to avoid falling into the water. After applying the pesticides, add new water in time to ensure the safety of shrimps. The rice field baking for shrimp farming should be done lightly, that is, the water level should be lowered until the field is exposed. The baking time should be short, and water should be added to the original position immediately after the baking is completed.

4. Stocking of shrimp fry. Stocking of shrimp fry begins in early July, with 20,000 to 30,000 shrimp fry per mu. Stocking should be done before 9 a.m. and the shrimp fry should be evenly stocked in the surrounding trenches. Plant appropriate amounts of revolutionary grass or water spinach in the surrounding trenches to provide a habitat for the shrimp.

5. Management of feeding and selling shrimp. Feeding should start after the shrimp fry are released. The feed should be a special shrimp pellet complete feed. Feed twice a day, that is, 8-9 am and 5-6 pm. The feeding amount in the morning is 1/3, and the feeding amount in the afternoon is 2/3. The daily feeding amount is about 5% of the shrimp body weight, which depends on the weather and the feeding situation of the shrimp. Feeding is mainly done in the surrounding ditches and nearby areas, and a small amount is fed appropriately in the field. Water is injected every 5-7 days, and the water level on the paddy field should be maintained at about 10 cm, so that the shrimp can feed in the field, increase the activity space and promote growth. In the hot season, change the water frequently to reduce the field water temperature and make it suitable for the growth of shrimp. When entering the water, filter it with 60-mesh gauze to prevent wild fish from entering the shrimp rice field.

6. Harvesting of shrimps. Rice is harvested around the time of frost. First, the water level should be gradually lowered to introduce shrimps into the shrimp ditch, and then the rice can be harvested after the field surface is exposed. After the rice is harvested, the water level can be deepened to about 1 meter, and feeding management can be continued. In winter, the shrimps can be caught and put on the market according to market conditions.

The "rice shrimp" model refers to a highly efficient ecological breeding model that uses rice fields as a basis, cultivates crayfish in rice fields without reducing grain production, and gives full play to the symbiotic and mutually beneficial effects of rice and crayfish, thereby achieving a double harvest of rice and crayfish. The details are as follows:

Rice field selection

Choose low-lying rice fields with sufficient water sources, strong soil water and fertilizer retention, no drought or flooding, no pollution around, good water quality, convenient drainage and irrigation, and sufficient sunlight for shrimp farming. The rice field area should be easy to manage and feed, and generally 40 to 50 mu is a suitable planting unit. For the first time, it is recommended to use rice fields with ready-made ditch systems to reduce the cost of shrimp farming construction projects.

Digging shrimp trench

A circular ditch is dug in a breeding unit. The circular ditch is dug 1.5 to 2 meters away from the ridge. The ditch is 2 to 3 meters wide and 1 to 1.5 meters deep. The outer ridge is about 2 meters wide and the slope ratio is 1:2.5. In order to facilitate shallow irrigation, field drying, fertilizer and pesticide application and fishing in rice fields, shrimp ditches and shrimp ponds must be dug in shrimp rice fields. The shrimp ditch in the field can be dug after transplanting rice seedlings. The digging method should depend on the shape, area and direction of the field. If the rice field is small, it can be dug into a "field" shape; if it is a long and large field, it can be dug into an inner "well" or inner "field" shape, with a ditch width of 0.5 to 1.0 meters and a ditch depth of 0.3 to 0.4 meters. The shrimp pond can be opened at the intersection of the shrimp ditch or the four corners of the field, and connected to the shrimp ditch. The shrimp pond is generally 1.0 meters square and 0.8 to 1.0 meters deep.

Strengthening the ridges

The soil from the excavated circular ditch can be piled up on the periphery to build the field ridge and compact, raise, widen and reinforce it to ensure that the field ridge is 0.6 to 0.8 meters above the field surface and about 2 meters wide at the top. Melons, beans, gourds, etc. can be planted on the field ridge. After the vines are on the racks, they can provide shade and heat relief in the hot summer. When digging shrimp trenches, small ridges can be left in the field to provide shrimp with enough places to dig holes.

Set up escape prevention facilities

When raising shrimp in rice fields, it is necessary to open the inlet and outlet well. The location should be selected on the earthen ridges at the two opposite corners of the rice field to facilitate the smooth inlet and outlet of the entire rice field during the breeding process. Wire mesh or double-layer dense mesh (about 20 meshes) should be installed at the inlet and outlet, and a fence with a height of 40 to 50 cm should be set on the ridge. Hard calcium plastic board or nylon mesh and hard plastic film can be used together or asbestos tiles can be used as fence materials; the corners of the field should be set in an arc shape to prevent escaped shrimp and natural enemies of adult shrimp from entering.

disinfect

About 15 days before the release of shrimp fry, dry disinfection is carried out, 75 kg of quicklime is spread per mu, and after 3-5 days of sun drying, new water is poured in to remove harmful organisms and parasites. Or disinfection with water: 125-150 kg of fresh quicklime is used per mu based on a water depth of 1 meter. Fresh quicklime should be dissolved in water and evenly sprinkled throughout the pond; or disinfection with bleaching powder, after dissolving the bleaching powder, sprinkle the whole pond, the dosage is 7 kg per mu, and the dosage of bleaching essence is halved; or disinfection with trichlorfon: 500 g of crystal trichlorfon is used per mu of water surface, plus 50 g of dichlorvos, and sprinkled throughout the pond after dissolving.

Fertilization

When new water is injected, it must be filtered to prevent wild fish and fish eggs from entering the pond with the water and affecting the survival rate of lobsters. At the same time, fertilization is applied to cultivate plankton as a direct natural feed for shrimps. Generally, 7 to 10 days before stocking, 300 to 500 kg of decomposed poultry and livestock manure is applied per mu to make the water color have a certain degree of fertility. At this time, the water level is shallow. As the water deepens, the amount of fertilizer should be gradually increased to improve the water quality and provide natural live bait such as cladocerans and copepods. In addition, 150 kg of snails can be put per mu, which can not only clean the water quality, but also serve as fresh natural bait for crayfish.

Aquatic plant species

Lobsters have a varied diet, although they prefer animals. However, when animal feed is insufficient, they will also eat aquatic plants to fill their stomachs. The aquatic plants that lobsters eat include cold-season grasses (Elodea, water peanut grass), hot-season grasses (Hydrilla verticillata, Vallisneria), water hyacinth and water lettuce. Aquatic plants are also ideal places for shrimps to hide and live, and are also good places for shrimps to molt. Raising shrimps in ponds with abundant aquatic plants has a high survival rate.

Variety Match

Generally, submerged plants and emergent plants are the main ones, and floating leaves and floating plants are supplemented; Vallisneria, Hydrilla verticillata, and Ceratophyllum, which are favored by lobsters, are planted; the coverage rate of water plants in shrimp ditches should be maintained at about 50% and more than 2 species; common grasses include Elodea, Vallisneria, and Hydrilla verticillata. Elodea is an early transitional and edible water plant, Vallisneria is an edible and hidden water plant, and Hydrilla verticillata is the main water plant that is effective in the long term.

Aquatic Plant Planting Methods

You can use the planting method (before stocking) or stepping planting, throwing method (floating leaf plants), sowing method (developed seeds, Vallisneria), transplanting method (emergent plants), cultivation method, bundling method, etc. It is mainly planted before the shrimp seeds are stocked, and can be replanted at any time. The growth area of ​​aquatic plants is controlled within 1/4 of the water surface.

Stocking time and quantity

Generally, it is from August to October every year or before the end of March of the following year. The first method is to release large-sized shrimps or broodstock after rice harvest. For the first breeding, 20-30 kg is released per mu, and for the existing rice fields, 5-10 kg is released per mu, with a female-to-male ratio of (2-3):1, mainly for the second year of production. The second method is to release shrimp fry, with a size of about 3 cm (250-600 pieces/kg), about 15,000 per mu, about 30-50 kg.

Quality requirements for shrimp fry and shrimp seed

The size of juvenile shrimps should be more than 0.8 cm, and the size of shrimp seeds should be about 3 cm. The size of shrimp fry and shrimp seeds in the same stocking location should be consistent, and they should be released in full at one time.

Good quality, strong physique, complete limbs, no disease or injury, strong vitality.

Shrimp fry selection: Shrimp fry should be artificially bred as much as possible. If it is wild shrimp, it should be domesticated for a period of time before being released to avoid fighting and killing each other.

Notes: 1. Stocking should be done on sunny mornings in winter, and on sunny mornings or rainy days in summer and autumn, avoiding exposure to the sun. 2. Before stocking, wash the shrimps with 3% to 5% salt water for 10 minutes to kill parasites and pathogens. 3. Shrimp purchased from other places should be slightly processed before stocking because they have been out of water for a long time. Soak the shrimps in the pond water for 1 minute, lift them up and set them aside for 2 to 3 minutes, and then soak them for 1 minute. Repeat this 2 to 3 times to allow the shrimps to absorb enough water on their body surface and gill cavity before stocking them to increase the survival rate. 4. Before stocking shrimp fry in spring, use small fish to test. First, use a bucket of water and put in a few small fish. After half an hour of observation, if the small fish are in normal activity and the water temperature is suitable, the shrimp fry can be put into the pond. When stocking shrimp fry, first sink the entire container containing the shrimp fry into the water, let the shrimp fry blend with the water in the pond, and then slowly pull out the container.

The key is specific practice. You can consult some relevant information and then make a decision based on your actual situation.

People training!!!!!!!

The key is specific practice. You can consult some relevant scattered information, and then make a decision based on your actual situation.

Experts needed