Rice crab planting and breeding method

Abstract

The invention provides a rice crab planting and breeding method which comprises the steps of rice field transformation, rice planting and juvenile crab throwing and feeding, and the rice field transformation comprises the steps that isolation meshes are installed on the periphery of a rice field and used for preventing blue crabs from escaping from the rice field; digging and building a juvenile crab collecting area on one side of the rice field for collecting juvenile crabs; a rice planting area and a juvenile crab breeding area are alternately dug and built in the rice field, the rice planting area is 0.2-0.5 m higher than the juvenile crab breeding area, the rice planting area is inclined to a seedling collecting area by 5-10 degrees, and a seedling collecting pipe is arranged between the juvenile crab breeding area and the seedling collecting area and used for collecting juvenile crabs to the seedling collecting area; a water return channel connecting the upstream of the rice planting area and the seedling collecting area is dug and built, the depth of the water return channel is 50-100 cm, the water in the rice field circularly flows, and bait is properly fed in time. According to the rice and crab planting and breeding method provided by the invention, saline-alkaline tolerant rice and scylla juvenile cultivation are combined, the water body space in the saline-alkaline tolerant rice field is fully utilized, and the method is a novel green, ecological and efficient income-increasing planting and breeding combined production mode.

Description

Technical Field

[0001] The invention relates to the technical field of aquaculture, and in particular to a rice-crab breeding method. Background Art

[0002] The mud crab, commonly known as the blue crab, belongs to the phylum Arthropoda, class Crustacea, order Decapoda, family Portunidae, genus Blue Crab. It is an aquatic crustacean. In my country, it is mainly distributed in the Yangtze River Estuary and the coastal waters to the south. It is an important marine fishery resource and marine economic crab in my country. Blue crabs are wide-temperature and wide-salinity animals. When the water temperature is above 18°C, young crabs feed and shed their shells to grow. The survival salinity is 1.0‰~55‰, and the adaptation range is 3.0‰~33‰ (specific gravity 1.002~1.025). Under natural conditions, the megalopause larvae of blue crabs follow the ocean currents, seek water salinity differences, and migrate to low-salinity areas such as the estuaries of coastal rivers and inner bays. They shed their shells and metamorphose into juvenile crabs, and live a benthic life, gradually shed their shells and grow up. In some areas, the salinity of the water body is only 3‰-5‰, and the young blue crabs still grow well. Juvenile blue crabs prefer to hide in shelters in the water. Too many juvenile crabs gathering in the same space will lead to fighting with each other, causing injuries and broken limbs, seriously affecting their survival rate.

[0003] As the blue crab is promoted to be cultivated in the northern coastal areas and inland saline-alkali land, the cultivation area is expanding year by year, and the demand for large-sized crab seedlings is also increasing rapidly. However, more than 90% of the large-sized blue crab seedlings sold on the market are caught natural seedlings, and the specifications are not uniform, which are easy to carry pathogens and have a low survival rate. Therefore, it is of great significance to develop high-quality large-sized blue crab seedlings cultivated artificially. Summary of the invention

[0004] The purpose of the invention is to provide a method for cultivating large-sized blue crab seedlings with controllable growth, high survival rate and high economic benefit.

[0005] To achieve the above object, the present invention provides a rice-crab breeding method, comprising the following steps:

[0006] Rice field transformation: Select salinized rice fields with good ecological environment, far away from pollution sources, natural bottom structure, good water retention performance, not flooded, sufficient water source, and convenient drainage and irrigation, and carry out the following transformation on the rice fields:

[0007] a. Install isolation nets around the rice fields to prevent mud crab seedlings from escaping from the rice fields;

[0008] b. Dig a seedling collection area on one side of the rice field to collect crab seedlings;

[0009] c. Alternately digging rice planting areas and juvenile crab cultivation areas inside the rice fields, the height of the rice planting area is 0.2 to 0.5 meters higher than the juvenile crab cultivation area, the rice planting area is set at a slope of 5 to 10 ° to the seedling collection area, and a seedling collection tube is provided between the juvenile crab cultivation area and the seedling collection area for collecting crab seedlings to the seedling collection area;

[0010] d. Dig and build a return channel connecting the upstream of the rice planting area and the rice seedling collection area. The depth of the return channel is 50 to 100 cm for the circulation of water in the rice fields;

[0011] Rice planting: Select salt-alkali tolerant rice varieties with good adaptability, and transplant rice according to the planting technology requirements of salt-alkali tolerant rice;

[0012] Release and feed crab seedlings: After rice is transplanted into the field and begins to grow, release blue crab seedlings and first-stage juvenile crabs. The seedling release point is the juvenile crab breeding area, and the area near the edge of the field is the main release area. Blue crab bait is released regularly, and the physical indicators of the water in the field are controlled when feeding the crab seedlings.

[0013] Preferably, the width of the rice planting area is 2 to 4 meters.

[0014] Preferably, the width of the juvenile crab breeding area is 0.5 to 1.5 meters.

[0015] Preferably, the width of the seedling collecting area is 2 to 3 meters, and the height of the plane of the seedling collecting area is 1 to 1.5 meters lower than the rice planting area.

[0016] Preferably, a drainage outlet and a drainage pipe are also provided in the seedling collection area to control the water level in the rice field.

[0017] Preferably, a water pump is provided in the seedling collection area to pump the water in the seedling collection area into the return channel to form a circulating flow of water in the rice field.

[0018] Preferably, the area of ​​the rice field is 1 to 5 mu.

[0019] Preferably, when transplanting rice, the rice row spacing is 25 to 30 cm, the plant spacing is 13 to 15 cm, and there are 3 to 4 plants in each hole.

[0020] Preferably, when crab fry are released for feeding, the density of crab fry release is 20,000 per mu.

[0021] Preferably, the physical indicators of the water in the field are controlled as follows when feeding crab fry: water temperature 26-32°C, salinity 1‰-5‰, dissolved oxygen 6-8mg / L, pH 7.0-8.0.

[0022] The beneficial effects of the present invention are as follows: the salt-alkali tolerant rice and mud crab breeding method provided by the present invention makes full use of the water space in the salt-alkali tolerant rice field by alternately setting up rice planting areas and young crab breeding areas in the rice field. The ditches in the rice planting area, young crab breeding area and seedling collection area can provide a good habitat for mud crab seedlings. The growth of rice can purify the water quality. At the same time, the excrement and bait residues of mud crab seedlings after ingesting bait can provide nutrients for rice after degradation, thereby reducing the amount of fertilizer applied. The rice-crab breeding technology method involved in the present invention is a new production model of combining breeding and raising with green ecology and high efficiency to increase income. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a top view of the structure of a rice field in a specific embodiment of the present invention;

[0024] Figure 2 It is a cross-sectional structural diagram of a rice planting area-juvenile crab breeding area of ​​a paddy field in a specific embodiment of the present invention;

[0025] Figure 3 It is a cross-sectional structural diagram of the seedling collection area and young crab cultivation area of ​​a rice field in a specific embodiment of the present invention.

[0026] 1. Seedling collection area; 2. Return channel; 3. Rice planting area; 4. Juvenile crab cultivation area; 5. Drainage outlet; 6. Water pump; 7. Isolation mesh; 8. Drainage intubation pipe; 9. Seedling collection pipe. DETAILED DESCRIPTION

[0027] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below. It should be noted that the following embodiments are only used to illustrate the implementation method and typical parameters of the present invention, and are not used to limit the parameter range described in the present invention. Reasonable changes derived therefrom are still within the scope of protection of the claims of the present invention.

[0028] It should be noted that the endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed in this article.

[0029] Unless otherwise defined, all terms, symbols and other scientific terms used herein are intended to have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. In some cases, terms with commonly understood meanings are defined herein for the purpose of clarification or ease of reference, and such definitions herein should not be construed as indicating significant differences from the commonly understood meanings in the art. The technical methods described or cited herein are generally well understood by those skilled in the art and are adopted by conventional methods.

[0030] A specific embodiment of the present invention provides a rice-crab breeding method, comprising:

[0031] Rice field transformation: Select salinized rice fields with good ecological environment, far away from pollution sources, natural bottom structure, good water retention performance, not flooded, sufficient water source, and convenient drainage and irrigation, and carry out the following transformation on the rice fields:

[0032] a. Install isolation mesh 7 around the rice fields to prevent mud crab seedlings from escaping from the rice fields;

[0033] b. Dig a seedling collection area 1 on one side of the rice field for collecting crab seedlings;

[0034] c. Alternately dig and build rice planting areas 3 and juvenile crab cultivation areas 4 inside the rice field, the height of the rice planting area 3 is higher than the juvenile crab cultivation area 40.2 to 0.5 meters, the rice planting area 3 is set at a slope of 5 to 10 ° to the seedling collection area 1, and a seedling collection tube 9 is provided between the juvenile crab cultivation area 4 and the seedling collection area 1 for collecting crab seedlings to the seedling collection area 1;

[0035] d. dig and build a water return channel 2 connecting the upstream of the rice planting area 3 and the seedling collection area 1. The water return channel 2 has a depth of 50 to 100 cm and is used for water circulation in the rice field;

[0036] Rice planting: Select salt-alkali tolerant rice varieties with good adaptability, and transplant rice according to the planting technology requirements of salt-alkali tolerant rice;

[0037] Release and feed crab seedlings: After rice is transplanted into the field and begins to grow, release blue crab seedlings and first-stage juvenile crabs. The seedling release point is juvenile crab breeding area 4, and the area near the edge of the field is the main release area. Blue crab bait is released regularly, and the water quality indicators in the field are controlled when feeding the crab seedlings.

[0038] See also Figure 1In the rice-crab breeding method provided in the above embodiment, rice planting areas 3 and juvenile crab breeding areas 4 are alternately dug inside the rice field, the width of the rice planting area 3 is 2 to 4 meters, and the width of the juvenile crab breeding area 4 is 0.5 to 1.5 meters, wherein the ratio of the total area of ​​the rice planting area 3 to the area of ​​the juvenile crab breeding area 4 conforms to the relevant national standards, and a seedling collection area 1 for collecting crab seedlings is dug on one side of the rice field, a return channel 2 is dug between the seedling collection area 1 and the upstream of the rice planting area 3, and a water pump 6 is arranged between the return channel 2 and the seedling collection area 1 for forming a water circulation flow in the rice field.

[0039] See also Figure 2 In the above embodiment, the height of the rice planting area 3 should be higher than the juvenile crab breeding area 4 to ensure that the blue crab seedlings grow in the juvenile crab breeding area 4.

[0040] See also Figure 3 In the above embodiment, the bottom plane of the seedling collection area 1 is the lowest point of the rice field, and the bottom plane height of the seedling collection area 1 is 31 to 1.5 meters lower than the rice planting area. A drainage port 5 and a drainage intubation pipe 8 are provided at the bottom of the seedling collection area 1 to control the water level of the rice field. A seedling collection pipe 9 is provided between the seedling collection area 1 and the young crab cultivation area 4, and the seedling collection pipe 9 is used to collect and capture blue crabs.

[0041] The technical solution of the present invention is further described below through specific embodiments.

[0042] Example 1

[0043] Rice-crab breeding experiment

[0044] The experimental rice field covers an area of ​​2 mu. Excluding the ridges, the field area is 1,000 square meters, 50 meters long and 20 meters wide. It is divided into 4 rice planting areas, 5 crab juvenile cultivation areas and 1 seedling collection area. Each rice planting area is 48 meters long and 4 meters wide; the crab juvenile cultivation area is 48 meters long and 1 meter wide; the seedling collection area is 20 meters long and 2 meters wide.

[0045] After 2 days of soaking and germination of salt-alkali tolerant rice seeds, the seedlings were raised in the nursery field for 15 days, and then transplanted to the rice planting area of ​​the experimental field. The field was flooded with water to cover the ground of the rice planting area, and the seedlings began to be transplanted, with a row spacing of 25 cm, a plant spacing of 15 cm, and 3 to 4 plants per hole. The rice began to grow 7 days after transplanting into the field. The first-stage juvenile crabs of blue crab seedlings were released into the field, with a release density of 20,000 per mu, and a total number of 30,000 seedlings. The seedling release point is the juvenile crab cultivation area, and the area near the edge of the field is the main release area, which is convenient for later feeding and growth inspection.

[0046] Feed twice a day, once in the morning and once in the evening. For the first 7 days of cultivation, choose Artemia, fish paste or shellfish meat as bait; for the next 10 days, choose shellfish meat and special feed for blue crabs as bait; for the next 10 days, choose shellfish meat and special feed for blue crabs as bait. After 25 days of cultivation, blue crab seedlings grow to 5-6 stage juvenile crabs, and the crab seedlings reach the catch specifications.

[0047] Before catching, drain and refill the rice planting area twice, so that the crab seedlings in the rice field can be concentrated in the young crab cultivation area and the seedling collection area along the water flow. Drain all the water in the young crab cultivation area for the last time, so that the crab seedlings can be concentrated in the seedling collection area this year. The drainage operation is used for a total of 5 days. Use feed tables, ground cages, etc. to catch blue crab seedlings in batches, and record the total number of blue crab seedlings caught.

[0048] The experimental results are shown in Table 1. After 30 days of cultivation, 7962 5th-stage juvenile crabs and 15545 6th-stage juvenile crabs were finally caught, totaling 23507 crabs, and the calculated breeding rate was 78.36%.

[0049] Table 1

[0050]

[0051] As can be seen from the above embodiments, the present invention makes full use of the water space in the salt-alkali tolerant rice field. The rice plants and the ditches in the culture area and the seedling collection area can provide a good habitat for the blue crab seedlings. The growth of rice can purify the water quality. At the same time, the excrement and bait residues of the blue crab seedlings after ingesting bait can provide nutrients for the rice after degradation, reducing the amount of fertilizer applied. The salt-alkali tolerant rice field comprehensive blue crab seedling intermediate cultivation technology method involved in the invention is a new production model of green ecological and efficient production and breeding.

[0052] Although the disclosure is disclosed as above, the protection scope of the disclosure is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the disclosure, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. A rice-crab breeding method, characterized in that: The following steps are involved: Rice field transformation: Select salinized rice fields and carry out the following transformations: a. Install isolation mesh (7) around the rice fields to prevent mud crab seedlings from escaping the rice fields; b. dig a seedling collection area (1) on one side of the rice field for collecting crab seedlings; c. Alternately digging rice planting areas (3) and juvenile crab cultivation areas (4) inside the rice field, the height of the rice planting area (3) is 0.2 to 0.5 meters higher than the juvenile crab cultivation area (4), the rice planting area (3) is set at a slope of 5 to 10 degrees toward the seedling collection area (1), and a seedling collection tube (9) is provided between the juvenile crab cultivation area (4) and the seedling collection area (1) for collecting crab seedlings to the seedling collection area (1); d. digging and building a return channel (2) connecting the rice planting area (3) upstream and the seedling collection area (1), the return channel (2) has a depth of 50 to 100 cm and is used for water circulation in the rice fields; Rice planting: Select salt-alkali tolerant rice varieties with good adaptability, and transplant rice according to the planting technology requirements of salt-alkali tolerant rice; Crab seedlings are released and fed: After rice is transplanted into the field and begins to grow, first-stage blue crab seedlings are released. The seedlings are released in the juvenile crab cultivation area (4). The area near the edge of the field is the main release area. Blue crab bait is released regularly, and the water quality indicators in the field are controlled when feeding the crab seedlings.

2. The rice-crab breeding method according to claim 1, characterized in that: The width of the rice planting area (3) is 2 to 4 meters.

3. The rice-crab breeding method according to claim 1, characterized in that: The width of the young crab cultivation area (4) is 0.5 to 1.5 meters.

4. The rice-crab breeding method according to claim 1, characterized in that: The width of the seedling collection area (1) is 2 to 3 meters, and the height of the bottom plane of the seedling collection area (1) is 1 to 1.5 meters lower than that of the rice planting area (3).

5. The rice-crab breeding method according to claim 1, characterized in that: The seedling collection area (1) is also provided with a drainage outlet (5) and a drainage intubation pipe (8) for controlling the water level in the paddy field.

6. The rice-crab breeding method according to claim 1, characterized in that: A water pump (6) is also provided in the seedling collection area (1) for pumping the water (6) in the seedling collection area (1) into the return channel (2) so that the water in the rice field forms a circulation flow.

7. The rice-crab breeding method according to claim 1, characterized in that: The area of ​​the rice field is 1 to 5 mu.

8. The rice-crab breeding method according to claim 1, characterized in that: When transplanting rice, the row spacing is 25 to 30 cm, the plant spacing is 13 to 15 cm, and there are 3 to 4 plants in each hole.

9. The rice-crab breeding method according to claim 1, characterized in that: When crab seedlings are released for feeding, the density of crab seedlings is 20,000 per mu.

10. The rice-crab breeding method according to claim 1, characterized in that: When feeding crab fry, the physical and chemical indicators of the water in the field are controlled as follows: water temperature 26-32℃, salinity 1‰-5‰, dissolved oxygen 6-8mg / L, pH 7.0-8.0.

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