阅读说明：本技术 一种稻田生态养殖小龙虾的方法 (Method for ecologically breeding crayfishes in rice field ) 是由 张茜 喻梅 尹静 王珍 张平 于 2020-07-16 设计创作，主要内容包括：一种稻田生态养殖小龙虾的方法,包括：稻田选址；田沟改造；进排水设置；防逃防涝；清田消毒；施肥；种草；放螺；虾苗选择；放养密度；放养；水稻品种选择；栽种方法；小龙虾投喂：亲虾、虾种投喂发酵配合饲料为主,配料为大豆饼30kg、玉米粉15 kg、小麦粉6 kg、麦麸10 kg、油糠8kg、鱼粉25kg、碳酸钙3kg、黏合剂2kg、磷酸二氢钾0.5kg、食盐0.5kg、红糖5kg、强微靓水素250g和强微豆粕发酵剂250g,水15-20kg；水质调节；水草管理；水稻管理；捕捞。本发明构建起完整的生态化养殖体系,真正实现保粮增收,减少杂草和病虫害,同时可降低小龙虾发病率,提高成活率,增大规格,并达到绿色食品标准。(A method for ecologically breeding crayfishes in a rice field comprises the following steps: selecting the site of the rice field; modifying a field ditch; water inlet and outlet arrangement; preventing escape and waterlogging; cleaning and disinfecting the field; fertilizing; planting grass; releasing snails; selecting shrimp larvae; breeding density; stocking; selecting rice varieties; a planting method; feeding crayfish: the fermented compound feed for feeding parent shrimps and shrimp seeds is mainly prepared from 30kg of soybean cakes, 15kg of corn flour, 6kg of wheat flour, 10 kg of wheat bran, 8kg of oil bran, 25kg of fish meal, 3kg of calcium carbonate, 2kg of adhesive, 0.5kg of monopotassium phosphate, 0.5kg of salt, 5kg of brown sugar, 250g of strong and micro water essence, 250g of strong and micro bean pulp leavening agent and 15-20kg of water; adjusting the water quality; managing aquatic weeds; managing the rice; and (6) fishing. The invention constructs a complete ecological culture system, really realizes grain protection and income increase, reduces weeds and plant diseases and insect pests, simultaneously can reduce the morbidity of crayfish, improves the survival rate, increases the specification and reaches the standard of green food.)

1. The method for ecologically breeding the crayfishes in the rice field is characterized by comprising the following steps of:

1) selecting the site of the rice field;

2) field ditch reconstruction: excavating circular ditches around the rice field, wherein the area of the circular ditches is not more than 10% of the area of the rice field;

3) water inlet and outlet arrangement;

4) preventing escape and waterlogging;

5) cleaning and disinfecting the field;

6) fertilizing;

7) planting grass: constructing a water body biological ecosystem with circulating symbiosis of animals, plants and microorganisms: planting waterweed and potamogeton crispus at the beginning of a month; spreading hydrilla verticillata and eel before and after clearing, and meanwhile, transplanting a proper amount of duckweed and water peanuts on the water surface;

8) selecting shrimp larvae;

9) stocking density: 15 Kg/mu of parent shrimps or self-retained parent shrimps with the specification of 35-50 g/tail are put in 8 middle ten days of the month;

10) selecting rice varieties;

11) a planting method;

12) feeding crayfish: the shrimp larvae feed on zooplankton, benthonic animals, various insects and tender shoots of weeds; the fermented compound feed is mainly used for feeding parent shrimps and shrimp seeds, and is matched with malt, snails, trash fish and soybeans, and the daily feeding amount is 5-8% of the weight of the lobster colony; wherein the formula of the fermented compound feed comprises 30kg of soybean cake, 15kg of corn flour, 6kg of wheat flour, 10 kg of wheat bran, 8kg of oil bran, 25kg of fish meal, 3kg of calcium carbonate, 2kg of adhesive, 0.5kg of monopotassium phosphate, 0.5kg of salt, 5kg of brown sugar, 250g of strong and slightly beautiful water element and 250g of strong and slightly soybean meal leavening agent, and 15-20kg of water is added; the preparation method comprises stirring the ingredients in a feed machine until the feed is dry and wet, stirring at 20 deg.C, sealing, fermenting for 4 days, and feeding when the pH value reaches 4;

13) water quality regulation: in the early spring period, the water depth of the field water is kept to be 10-15cm, the water temperature is increased, and feeding and activities of crayfish are promoted; gradually deepening the water level along with the continuous growth of the crayfish, wherein the water level is 30cm in the first ten days of April, the water depth is extended to the rice field in the middle ten days of April, the water level is reduced at the bottom of 5 months and at the beginning of 6 months, so that the crayfish returns to the zigzag ditch, is caught to be large and small, and is planted in the whole field;

14) managing aquatic weeds;

15) rice management: in the aspect of paddy field fertilization, fertilization is not needed, if fertilization is needed, compound fertilizer is applied and the application amount is controlled, and the fertilizer cannot be directly scattered into an annular ditch; in the aspect of disease control, rice diseases and insect pests are controlled by combining an insecticidal lamp and a sex attractant, so that the rice can be applied when the rice is not applied, and high-efficiency low-toxicity pollution-free pesticides and biological agents are selected when the rice is applied, so that the use of insecticides containing pyrethrins and organophosphorus is avoided;

16) and (6) fishing.

2. The method for ecologically breeding the crayfishes in the rice field as claimed in claim 1, wherein the method comprises the following steps: the rice field area in the step 1) is 40-50 mu.

3. The method for ecologically breeding the crayfishes in the rice field as claimed in claim 2, which is characterized in that: the size of the circular ditch in the step 2) is set to be 4-5m wide at the upper opening, 1.5-2.5m wide at the bottom, 1.2m deep, 1:1.5 slope ratio, 1.5m wide at the ridge and 1m high at the ridge.

4. The method for ecologically breeding the crayfishes in the rice field as claimed in claim 3, wherein the method comprises the following steps: the rectangular furrows and the well-shaped furrows of the rice field are not formed.

5. The method for ecologically breeding the crayfishes in the rice field as claimed in claim 1, wherein the method comprises the following steps: in the step 7), the aquatic biological ecosystem mainly comprises submerged plants and secondarily comprises emergent aquatic plants and floating plants, wherein the ratio of the emergent aquatic plants to the floating plants is 7: 3.

6. The method for ecologically breeding the crayfishes in the rice field as claimed in claim 1, wherein the method comprises the following steps: the planting method of the step 11) comprises the following steps: transplanting seedlings by a transplanter with the row spacing of 20cm and the row spacing of 30cm, and planting 1.1 ten thousand seedlings per mu.

7. The method for ecologically breeding the crayfishes in the rice field as claimed in claim 1, wherein the method comprises the following steps: the step 15) disease control of rice management: when the water aqua is selected as the medicament, the water aqua is sprayed in the morning and evenly sprayed on the rice leaf surfaces.

Technical Field

The invention relates to a crayfish breeding method, in particular to a rice field ecological crayfish breeding method, and belongs to the technical field of aquaculture.

Background

In recent years, with the continuous and clear land circulation policy in rural areas of China, the pace of agricultural industrialization is accelerated, the nation vigorously develops the industrialization and large-scale operation of the rice field, the innovation and the development of the comprehensive planting and breeding of a new round of rice field are promoted, and a new round of the comprehensive planting and breeding wave of the rice field is lifted up and down in the nation. At present, the comprehensive breeding of the rice field in China is mainly used for breeding the crayfish in the rice field, the breeding area is greatly increased year by year, but the problems of low specialized level of rice shrimp breeding enterprises (cooperative society), unsmooth breeding technology, dryness of people, worry about earning money, insufficient preparation, short-rise in a warehouse, low unit yield of a part, poor benefit and the like are solved, the overall breeding level is to be further improved, and the bred crayfish is small in size, large in disease and poor in color and luster. In order to seek the maximization of yield and benefit, breeding enterprises (cooperative society) basically develop a high-density intensive culture mode by digging too wide a circular ditch of a rice field and seriously imbalance the ratio of the area of the rice field to the area of the circular ditch, and basically lose the significance of comprehensively culturing rice shrimps. In addition, in order to save cost, a plurality of breeding enterprises purchase cheap special feed for crayfish, the feed has poor palatability and low utilization rate, the water quality is spoiled by the residual feed, and the crayfish has ecdysone and enzyme secretion disorder phenomena, so that the crayfish does not have a tunnel for ecdysis and even dies, and the feed is also a low main factor for the benefit of the crayfish bred in the paddy field.

At present, there are two modes for breeding crayfish in rice field: one is to put the parent shrimps directly in the shrimp ditch of the rice field to allow them to breed naturally, and then to breed in the next year. The disadvantages of the breeding mode are that if the size of the offspring seeds in 3 months only reaches 1cm, the adult crayfishes of the crayfishes come into the market late, a large number of crayfishes cannot reach the market size in high-temperature seasons, the fishing difficulty is increased, the number of diseases is large, and the final yield and the benefit are unstable. Therefore, the method directly puts the parent shrimps in the shrimp ditches in the rice field in 8 months, naturally breeds the parent shrimps, develops breeding work as early as possible, realizes large-size seedlings in early spring, and puts large-size commercial shrimps on the market in advance, and is a key link in the whole culture. In another mode, shrimp seedlings are directly purchased from the market or artificially bred for stocking, and the newly excavated rice field is common in the other mode, and the defects that the purchased shrimp seedlings are not in the same batch and have different growth specifications are overcome; the young shrimps have different degrees of damages on the body surface in the transportation process, the survival rate is low, the breeding risk of part of breeding houses is large, the breeding benefit is low, and the breeding enthusiasm is not high.

In conclusion, the existing method for the ecological cultivation of various rice and shrimps by the co-culture method is simple in cultivation mode, essentially, the cultivation mode is only the simple combination cultivation of the rice and the shrimp, the ecological characteristics and the growth requirements of the rice field planting and the crayfish cultivation are not carefully and deeply aimed at, various problems in the cultivation process are solved, the ecological environment with complementary symbiosis cannot be really established and maintained, and the ecological healthy cultivation purpose of 'cultivating the rice and the shrimp and the rice' is achieved.

Disclosure of Invention

In order to overcome the defects in the prior art, the invention provides a method for ecologically breeding crayfishes in a rice field, which is characterized in that the steps of the method for comprehensively and finely optimizing the breeding are carried out according to the symbiotic principle of the crayfishes bred in the rice field, so that a real ecological breeding system is constructed; the method can really realize grain protection and income increase, reduce rice weeds and plant diseases and insect pests, simultaneously reduce the morbidity of the crayfish, improve the survival rate, advance the time to market of commodity lobsters, increase the specification of the commodity lobsters, sell the commodity lobsters in time, improve the price of the lobsters and greatly increase the economic benefit.

The technical scheme adopted by the invention for solving the technical problems is as follows: the method comprises the following steps:

1) selecting the site of the rice field;

2) field ditch reconstruction: excavating circular ditches around the rice field, wherein the area of the circular ditches is not more than 10% of the area of the rice field;

3) water inlet and outlet arrangement;

4) preventing escape and waterlogging;

5) cleaning and disinfecting the field;

6) fertilizing;

7) planting grass: constructing a water body biological ecosystem with circulating symbiosis of animals, plants and microorganisms: planting waterweed and potamogeton crispus at the beginning of a month; spreading hydrilla verticillata and eel before and after clearing, and meanwhile, transplanting a proper amount of duckweed and water peanuts on the water surface;

8) selecting shrimp larvae;

9) stocking density: 15 Kg/mu of parent shrimps or self-retained parent shrimps with the specification of 35-50 g/tail are put in 8 middle ten days of the month;

10) selecting rice varieties;

11) a planting method;

12) feeding crayfish: the shrimp larvae feed on zooplankton, benthonic animals, various insects and tender shoots of weeds; the fermented compound feed is mainly used for feeding parent shrimps and shrimp seeds, and is matched with malt, snails, trash fish and soybeans, and the daily feeding amount is 5-8% of the weight of the lobster colony; wherein the formula of the fermented compound feed comprises 30kg of soybean cake, 15kg of corn flour, 6kg of wheat flour, 10 kg of wheat bran, 8kg of oil bran, 25kg of fish meal, 3kg of calcium carbonate, 2kg of adhesive, 0.5kg of monopotassium phosphate, 0.5kg of salt, 5kg of brown sugar, 250g of strong and slightly beautiful water element and 250g of strong and slightly soybean meal leavening agent, and 15-20kg of water is added; the preparation method comprises the steps of putting the ingredients into a feed machine for stirring, wherein the feed can be agglomerated and dispersed when the feed is dry and wet, and can be fed when the pH value reaches 4 after the feed is fermented for 4 days at the temperature of 20 ℃ after being uniformly stirred;

13) water quality regulation: in the early spring period, the water depth of the field water is kept to be 10-15cm, the water temperature is increased, and feeding and activities of crayfish are promoted; gradually deepening the water level along with the continuous growth of the crayfish, wherein the water level is about 30cm in the first ten days of April, the water depth is overflowed to the rice field in the middle ten days of April, the water level is reduced at the bottom of 5 months and at the beginning of 6 months, so that the crayfish returns to the clip-shaped ditch, is caught and left large and small, and is planted in the whole field;

14) managing aquatic weeds;

15) rice management: in the aspect of paddy field fertilization, fertilization is not needed, if fertilization is needed, compound fertilizer is applied and the application amount is controlled, and the fertilizer cannot be directly scattered into an annular ditch; in the aspect of disease control, rice diseases and insect pests are controlled by combining an insecticidal lamp and a sex attractant, so that the rice can be applied when the rice is not applied, and high-efficiency low-toxicity pollution-free pesticides and biological agents are selected when the rice is applied, so that the use of insecticides containing pyrethrins and organophosphorus is avoided;

16) and (6) fishing.

Compared with the prior art, the method for ecologically breeding the crayfishes in the rice field has more breeding steps, comprehensively refines and deeply manages, particularly builds and maintains a good ecological environment in the whole breeding process in the aspects of grass planting, crayfish feeding and the like, and thereby wins the win-win situation in the aspects of the yield and the quality of the rice and the crayfishes. The advantages of one-water dual-purpose and one-field dual-purpose are really realized, grain production and income increase of farmers and fishermen can be effectively promoted, rice weeds and plant diseases and insect pests are reduced, the morbidity of the crayfish can be reduced, the survival rate is improved, the time of selling the commercial lobsters is shortened, the specification of the commercial lobsters is increased, the crayfish is sold in time staggered, the price of the lobsters is improved, the unit income is increased, and great ecological benefits are brought into play.

The embodiment on the aspect of crayfish is as follows: 1) the scientific grass planting method is applied, the diversity, the hierarchy, the stage and the seasonal nature of the aquatic grass are kept, submerged plants are mainly planted in different stages and different seasons according to different characteristics of the aquatic grass, emergent plants and floating plants are assisted, the diversity of a water body biological system is created, the propagation of beneficial microorganisms in the water body is promoted, the release of harmful algae in the water body is inhibited, a circulating symbiotic ecological system is created, and a good ecological healthy environment is created for the growth of the crayfish. The waterweed and the curly pondweed have extremely strong adaptability, the curly pondweed germinates in autumn and grows in winter and spring, the waterweed can grow at the low temperature resistant temperature of 5 ℃, and the waterweed grows when other waterweeds do not germinate, so that palatable vegetal bait is provided for the rice and shrimp rotation mode crayfishes. The hydrilla verticillata and the eel caltrop have the advantages of high temperature resistance, proper growth at the water temperature of 22-32 ℃, complementary advantages with the waterweed and the curly pondweed, and good ecological environment is created for different growth stages of the crayfish. 2) The snail feeding in the rice field and the ring ditch is also one of the key measures in the crayfish breeding process. The spiral shell has the advantages of low price, wide sources, delicious meat, rich nutrition, high utilization rate and strong fecundity, and is an important natural animal bait source for the crayfishes. The spiral shell as a benthic organism can timely remove residual bait and excrement at the bottom, improve the substrate of a rice field, prevent bottom bacteria from breeding, and simultaneously can prevent the occurrence rate of grass clamping of lobsters at the middle and later stages of cultivation to a certain extent. In the culture process, the snails are palatable natural animal baits for crayfishes, and the snails shells are also mineral baits and can provide a large amount of calcium. By applying the scientific snail placing method, the bottom residual bait excrement can be timely cleared away, the bottom of the rice field is improved, the bottom bacterium breeding is prevented, the problems that the crayfish is difficult to exuviate in the crayfish breeding process and shells are quickly hardened after exuviation are solved, the crayfish shelling process is accelerated, the crayfish growth is promoted, the crayfish quality (large number of freshwater shrimps) is enhanced, the marketing specification of the crayfish is increased, the crayfish yield is increased, the breeding cost is reduced, and the economic benefit is improved. 3) The self-made fermented compound feed has the effects of improving substrate, tendering water, reducing ammonia nitrogen, reducing PH value and inhibiting harmful bacteria in water during the culture process; the crayfish breeding method can effectively promote crayfish to shell quickly after shelling, increase the survival rate of crayfish shelling, reduce the occurrence of diseases, and the bred crayfish is strong in offshore activity, good in quality (more in freshwater shrimps), large in specification and compact in meat quality.

The embodiment in rice is as follows: compared with the rice single crop under the same condition, the method has the advantages that the pure income per unit area is averagely increased by more than 50 percent by applying various prevention and control measures such as grass planting, snail releasing, biological agent utilization, self-made fermented compound feed disease prevention and the like; the usage amount of the fertilizer is reduced by more than 40 percent, and the usage amount of the pesticide is reduced by more than 60 percent, thereby increasing the income and effectively maintaining the ecological environment.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are a part of the embodiments of the present invention, but not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, belong to the scope of the present invention.

The invention discloses a method for ecologically breeding crayfishes in a rice field, which comprises the following operation steps:

1. site selection of rice field: the rice field for shrimp culture is usually selected in the places with convenient traffic, sufficient water source, low terrain, good water and fertilizer conservation, convenient irrigation and drainage and sufficient water source. The water quality requirement is fresh and pollution-free, meets the national standard of fresh water quality of fishery water, and is generally river water or lake water. The area of the rice field is preferably 40-50 mu.

2. Field ditch reconstruction: the method is characterized in that circular ditches are excavated around the rice field to build auxiliary peduncles, and soil excavated by excavating the circular ditches is mainly used for heightening and reinforcing ridges which are guaranteed not to crack, leak and collapse. Taking a 50 mu rice field as an example, the section of a circular ditch is trapezoidal, the width of the upper opening is 4-5m, the width of the bottom is 1.5-2.5m, the depth is 1.2m, the slope ratio is 1:1.5, the width of a ridge is 1.5m, and the height of the ridge is 1 m. The area of the dug circular ditch does not exceed 10 percent of the area of the rice field, the cross-shaped ditch and the well-shaped ditch are not formed on the ridge surface, a mechanical channel is reserved during digging, the machine can be ensured to be operated on the ridge, a boat can be operated in the ditch, and the mechanized operation is facilitated. The reason that the area of the circular ditch does not exceed 10 percent of the area of the rice field is that the symbiotic mutual benefiting effect of the rice and the lobsters is exerted on the premise of grain stabilization, so that the double harvest of the organic rice and the organic lobsters is obtained, the agricultural efficiency improvement and income increase of farmers (fishers) are promoted, the current resource environment pressure is relieved, the ecological civilization construction development is promoted, and the structural reform and implementation of the agricultural supply side are promoted.

3. Water inlet and outlet are arranged: the water inlet and outlet are separated, the water inlet and outlet are arranged at the opposite corners of the rice field, and the falling ratio of the water inlet to the water outlet is 3%. The water inlet and drainage facilities need to be well prevented from escaping, the established water inlet and drainage channel needs to be regularly repaired on the principle of no escape of shrimps and no water blocking, and the water inlet and drainage channel is ensured to be filled with water and drained out.

4. Escape-proof facilities: the crayfish has strong climbing and escaping capability, and special attention needs to be paid to installation of escape-proof facilities during breeding. Anti-escape facilities are arranged around the ridge. The setting method comprises the following steps: the ridges are fixed by wooden piles or bamboo poles every 1.5-2 m, the two ends of the wooden piles or bamboo poles are provided with escape-proof facilities such as polyethylene net pieces, the height of the escape-proof facilities is 40-50 cm, the corners of the field block are arc-shaped, and joints are smooth and have no gaps.

5. Field cleaning and disinfection: 50kg of quicklime is used for melting and sprinkling the whole pond in the circular ditch of each mu of rice field before the breeding day to kill wild trash fish, enemy organisms and harmful bacteria.

6. Fertilizing: injecting water into the field for 40-60cm 7-10 days before seedling placing, and applying 200-300 kg/mu of organic fertilizer in the field and the annular ditch at one time. After the fertilizer is applied, part of rotten organic fertilizer can be directly eaten by the crayfish as bait; the other part of the microorganisms are propagated in a large quantity, the organic debris is increased in a large quantity, and rich bait resources are provided for the crayfishes.

7. Planting grass: the method for cultivating the crayfish and the grass firstly, and the type, the collocation and the planting method of the aquatic grass are key measures for judging whether the crayfish is successfully cultivated or not. In order to keep the diversity and the hierarchy of the aquatic weeds, the method mainly comprises the steps of planting submerged plants in different stages according to the characteristics of the aquatic weeds, and constructing the diversity of a water body biological system by taking emergent aquatic plants and floating plants as auxiliary plants, thereby promoting the propagation of beneficial microorganisms in the water body, inhibiting the release of harmful algae in the water body, and creating an ecological system with the circulating symbiosis of animals, plants and microorganisms. According to the characteristics of the aquatic weeds, 2-3 dominant species are selected, so that the singleness is avoided, the advantages of various aquatic weeds are exerted, the proper aquatic weeds are ensured to exist in different growth stages of the crayfishes, and the scientific grass planting method is invented. The method comprises the following steps: according to the low-temperature resistant and good palatability characteristics of the waterweed and the curly pondweed, the waterweed and the curly pondweed are planted at one month and become ideal aquatic organisms for the early shrimp field. The hydrilla verticillata and the eel grass can favor high temperature, the shrimps like food and are not easy to damage, and the like, and can become major breeds in middle and later periods. Before and after Qingming, hydrilla verticillata and eel grass are scattered, and simultaneously, a proper amount of duckweed and alternanthera philoxeroides are transplanted on the water surface, and the water grass is distributed sporadically. The aquatic weeds transplanted or cultivated in the field need to be disinfected, and the aquatic weeds are generally soaked in 3% saline solution for 5-10 minutes for disinfection. The area of the aquatic weeds in spring is not more than 40%, and the area of the aquatic weeds is kept not more than 60% of the circular ditch in summer.

8. Releasing the snails: the throwing of the spiral shells can purify water on one hand, and can be used as animal baits for lobsters on the other hand, and shells left by eating the remaining spiral shells can also provide certain calcium for water bodies to promote the growth and exuviation of the crayfishes. The method for releasing the snails comprises the following steps: stocking for 2 times in the cultivation process, generally selecting the middle and last ten days of 3 months, and putting 60kg of snails per mu. And 5, stocking for the second time in the last ten days of 8 months, and putting 100kg of the feed per mu. The snails are disinfected by 4-5% of salt water for 5 minutes before being put into a pond and are uniformly scattered at each corner of a rice field, so that the problem that a bag is poured into one corner or one point of the snails to cause water quality pollution caused by death of a large amount of snails sinking at the bottom due to oxygen deficiency is avoided.

9. Selecting parent shrimps: the lobsters with strong vitality, smooth and bright body surface, complete limbs, strong constitution, regular specification and strong vitality are selected as the parents.

10. Stocking density: the shrimp is thrown or left by oneself into the pond with the shrimp volume of about 15 Kg/mu and the specification of 35-50 g/tail. The ratio of male to female is 5: 2.

11. Stocking: before stocking, 3% saline solution is used for soaking and disinfecting, when the shrimp basket is put in, a rice field slope or a place with more aquatic plants and luxuriant grasses on the field surface is selected, the shrimp basket is put in a point-by-point mode, the shrimp basket is generally put on the side, the shrimp seedlings automatically climb out of the shrimp basket, and the shrimp seedlings are put in carefully and quickly without damaging the shrimps.

12. Parent shrimp cultivation: firstly, the early breeding of the crayfish is realized when the parent crayfish is put in the early stage and at normal temperature, the key point is that the egg-carrying crayfish is obtained in advance, and the fertilized eggs of the crayfish can be hatched into the young crayfish in autumn by depending on the natural temperature at a high position, so that the parent crayfish of the crayfish is cultured in advance, and the parent crayfish requires 35-50 g/tail weight, dark red body color, strong appendage and strong activity. Secondly, after the parent shrimps with stable water level in the circular ditch are cultivated for a period of time, the parent shrimps are dug to lay eggs successively, the temperature is generally 24-28 ℃, the parent shrimps are still dug out to find food, and the fertilized eggs hatch young shrimps in about 10 days under the good environment and the higher water temperature. In order to meet the living needs of parent lobsters, the water in the annular ditch is kept at 60-80cm, so that the situation that the water is not lower than the normal water line to cause the egg-carrying shrimps to cave in advance, and cannot exceed the normal water line or even submerge the cave, and the lobsters are dug again to influence the normal egg laying of the female shrimps is guaranteed. The hole digging period of the crayfishes is just the rice grouting period, and the water level in the annular ditch does not exceed the auxiliary ridge.

13. Breeding shrimp larvae: the breeding of the young shrimps is carried out in the circular ditch of the rice field, fertilized eggs generally hatch young shrimps in the middle and the last ten days of 9 months, the young shrimps have the habit of protecting the young, the young shrimps cannot leave the parent body immediately after demoulding and generally attach to the swimming feet of the parent body, and the young shrimps can leave the parent body for independent life 5 to 7 days after emergence of seedlings. When the young crayfish is separated from the parent, the body length is only 9-12mm, the resistance to the outside is poor, and the crayfish is easy to die. When 90% of the egg-carrying shrimps are found not to be attached with the larvae, the parent shrimps should be timely harvested and sold for cultivation.

14. Daily management work for culturing shrimp fries insists on pond patrol every day, and when a large number of shrimps are found in a water body, postpartum parent shrimps should be timely caught and juvenile shrimp culturing work should be immediately carried out. The temperature is very suitable for the growth of the shrimps, the water level is properly reduced by 20-30cm, the water temperature is increased, and meanwhile, the bait feeding is enhanced. Fresh water can be added for 2-3 times per week to promote growth and molting of larva. Strengthening management, ensuring that the crayfish fries are cultivated in the middle and last ten days of 10 months, enabling the size of the crayfish to reach 2-3cm, providing large-size crayfish seeds for the spring of the next year, and preparing for appearing on the market in advance.

15. Feeding young shrimps: the water quality is fertilized before the young shrimps emerge, and the biological content of the bait in the water is ensured to be 15-20 per ml. The method mainly comprises the steps of taking zooplankton such as rotifers, cladocera larvae and the like as the main material when feeding is started, filtering the rotifers or cladocera larvae which are fed by using a 40-mesh bolting silk net if the rotifers or cladocera larvae are cultured in a pond, disinfecting the filtered rotifers or cladocera larvae by using 2-3% saline solution, and feeding the rotifers or cladocera larvae for 4-5 times every day to ensure the content of bait organisms in water; or feeding soybean milk; after feeding for 5-7 days, the self-made fermented compound feed can be fed instead. The feeding amount is 0.2-0.3kg per ten thousand lobsters in the early stage, and the feeding amount in the later stage is 5-8% of the weight. The feeding amount of each day is flexibly mastered according to the activity condition, water temperature, water quality, weather and the like of the shrimp larvae by adhering to the 'four definite' principle during feeding.

16. Selecting rice varieties: the rice variety is selected from the varieties with strong tillering capability, small leaf opening angle, developed root system, stout stem, disease resistance, insect resistance and lodging resistance.

17. The planting method comprises the following steps: transplanting seedlings by a transplanter, shallow sowing, wherein the row spacing is 30cm, the plant spacing is 20cm, and the seedling planting amount is about 1.1 ten thousand seedlings per mu.

18. Feeding crayfish: the early shrimp larvae feed on zooplankton, benthonic animals, various insects and weed tender shoots; the fermented compound feed is mainly fed in the middle and later periods, and is matched with malt, snails, trash fish, soybeans and the like, and the daily feeding amount is 5-8% of the weight of the lobster group.

19. The method for preparing the self-made fermented compound feed comprises the following steps: the formula comprises 30kg of soybean cake, 15kg of corn flour, 6kg of wheat flour, 10 kg of wheat bran, 8kg of oil bran, 25kg of fish meal, 3kg of calcium carbonate, 2kg of adhesive, 0.5kg of monopotassium phosphate, 0.5kg of salt, 5kg of brown sugar, 250g of strong and slightly beautiful water and 250g of strong and slightly soybean meal leavening agent, and 15-20kg of water is added; stirring in a feed machine until the feed is dry and wet, fermenting at 20 deg.C for 3-4 days, and feeding when pH reaches about 4. Before feeding, the fermented feed is extruded into strip-shaped soft granules by using a soft granule machine, so that the loss of the bait in water can be reduced.

20. Water quality regulation: the water level is adjusted according to a method of 'moderate spring shallow, summer full and autumn', the water level adjustment of the rice field is an important link in the process of shrimp culture in the rice field, rice is taken as the main material, the growth requirements of crayfish are considered, and the water level is managed according to the principle of 'shallow-deep-shallow'. In early spring, the water in the field is shallow, the water depth is kept at 10-15cm, the water temperature is increased, and the feeding and activity of the crayfish are promoted. The water level is gradually deepened along with the continuous growth of the crayfish, the water level is about 30cm in the first ten days of April, the water depth can be extended to the rice field in the middle ten days of April, the activity space of the crayfish is increased, and the growth of the crayfish is promoted. And (5) lowering the water level at the bottom of the month and at the beginning of the month and 6 to enable the lobsters to return to the square ditch, catching the lobsters, keeping the lobsters large and small, and transplanting the lobsters in the whole field. Keeping the transparency of 25-40cm, putting 150 silver carps with the specification of 100 g/silver carps into the ring trench, applying quicklime once in 15-20 days, and applying 10-15 kg/mu in water depth of 1 m.

21. Managing aquatic weeds: the aquatic weeds can purify water quality, increase dissolved oxygen, shade and cool, provide palatable plant baits for the crayfishes, and provide places and proper ecological environment for safe crayfish shelling. The method plays an important role in improving the commodity specification, quality, yield and benefit of the crayfish, and is also an indispensable part in crayfish culture. The water plants are kept strong, active, vigorous and clean in the early stage of cultivation for 2-4 months. And (3) topdressing 2-3kg of compound fertilizer per mu in early Illa algae growing season at the bottom of March to avoid rotten grass and rotten grass roots caused by mineralization of water quality or phenomena of excessive concentration of water and fertilizer, death of water grass and the like. The height of the aquatic weeds is maintained and the water quality is maintained regularly in the middle and later periods of cultivation, and the water quality needs to be 'fertile, alive, tender and cool'. In last ten days of June, in order to prevent the water quality of the waterweed and the potamogeton crispus from excessively growing, rotting and corrupting, the water level is slowly deepened, the grass heads are submerged below 30cm of the water surface or the grass heads are cut off in time, and the waterweed and the potamogeton crispus are properly removed. The area of the aquatic weeds in the early stage of cultivation is not more than 40% of that of the circular ditch, and the area of the aquatic weeds in the middle and later stages is kept not more than 60% of that of the circular ditch.

22. Rice management: firstly, field water level control: and (5) throwing seedlings, and keeping the water level at 8-10 cm. After 7 days, the water level was kept at 10-15 cm. After 2 months, the water level was gradually increased to 20-25 cm. After heading, the water level is reduced to below 20 cm. And in the grouting period, wet irrigation is adopted, and the dry, wet and yellow mature period of the field surface is kept. After harvesting the rice ears, the water level of the rice field is kept between 50 and 60 cm.

Fertilizing in rice field: when the crayfishes are cultivated in the rice field, the base fertilizer, the crayfish metabolites, the residual feed and the like are applied as fertilizers, so that the rice generally does not need to be applied with fertilizers when growing. If the fertilizer is required to be applied, the compound fertilizer is applied and the application amount is controlled, and the fertilizer can not be directly scattered into the annular ditch.

Thirdly, disease control: the crayfish is cultivated in the rice field, the rice diseases and insect pests are greatly reduced, and the good prevention and control effect can be achieved by combining the insecticidal lamp, the sex attractant and the like. The principle of using the pesticide for culturing shrimps in the rice field is that the pesticide can be applied when the pesticide is not used, and the pesticide is selected from high-efficiency low-toxicity pollution-free pesticide and biological agent when the pesticide is needed, so that the pesticide containing pyrethrins and organophosphorus is not used. The concentration of the medicine should be strictly controlled when the medicine is applied. The spraying water agent is generally sprayed on the leaf surfaces evenly in the morning.

Fourthly, field patrol management: and (5) insisting on daily field patrol, checking whether the ridge has a leak or collapses and whether the blocking net of the water inlet and outlet is damaged, and observing the feeding condition of the crayfishes. During rainstorm, the phenomena of escape of crayfish or dead crayfish caused by water overflowing the ridge field or inflow of industrial toxic sewage and pesticide are prevented.

Drying the land in the sun: cleaning the surface of the field before sunning the field, and keeping the water depth of the circular ditch to be 60-70 cm. The land is lightly and briefly dried, the land is not sunk when being dried, and the surface of the land is white.

23. Fishing: and 5 months, fishing the lobsters with large size and small size, wherein the lobsters with the size of more than 30g come into the market, and putting the lobsters with the small size back into the water body for continuous cultivation. Fishing for the second time in the first october ten days of 9 months, fishing the parent shrimps after spawning to go to the market, and culturing the juvenile shrimps.

According to the method for ecologically breeding the crayfishes in the rice field, natural resources are fully utilized, the production potential of the rice field is excavated, the rice field is excavated strictly according to the national standard of the technical Specification for comprehensive breeding and fishing of rice and fishery, the area of the rice is ensured, and the purposes of grain conservation and income increase are achieved. In particular, the invention relates to a formula of a self-made fermented compound feed. The 'strong and micro bean pulp leavening agent' mentioned in the formula can thoroughly remove soybean antigens and anti-nutritional factors, the fermented bean pulp contains probiotics such as lactic acid bacteria and the like, inhibits harmful bacteria and acidifies intestinal tracts, can be directly absorbed through intestinal tract mucosa, improves the utilization rate of plant protein, and increases the utilization rate of bait; the strong and slightly beautiful water element has the functions of absorbing and assimilating ammonia nitrogen and nitrate and decomposing organic suspended matters in a water body, thereby relieving the eutrophication of the water body and keeping the water quality to be fertile, tender and refreshing; the strong and micro bean pulp leaven and the strong and micro water essence are used in the two biological agents to prepare the self-fermented compound feed, so that the feed has good palatability and easy digestion, greatly reduces the risk of enteritis, can effectively help crayfishes to crust shells quickly after shelling, has high bait utilization rate, and the bred crayfishes have strong offshore activity, good quality (more crayfishes), large specification and compact meat, and improve the economic benefit. The brown sugar is added into the feed, on one hand, the energy substances of various monosaccharides and polysaccharides such as glucose and fructose contained in the brown sugar effectively supplement the energy required by the growth of the lobsters, promote metabolism, increase the immune function of the lobsters, prevent diseases and reduce morbidity and mortality. On the other hand, brown sugar contains rich carbon which is a nutrient source of algae, can promote the propagation of algae and microorganisms, and provides a good water body environment for the growth of lobsters. In conclusion, the brown sugar added into the self-made compound feed is beneficial to promoting the growth of the lobsters, improving the immune function of the lobsters, stabilizing the water quality and promoting the propagation of algae and microorganisms, so that the growth of the crayfishes is promoted, the specification of the lobsters is increased, and the breeding benefit is improved.

The method is tested and applied to special aquaculture cooperative society of Gong Chong and Yi in Guangxi county and town of suining county, the yield of crayfish per mu is 131kg, the yield of pollution-free rice per mu is 503kg, the profit per mu is 7000 yuan, and the annual profit of the experimental base can reach 230 ten thousand. Radiation drives surrounding farmers to voluntarily develop a rice and fish comprehensive planting and breeding mode, so that the rice and fish comprehensive planting and breeding area is rapidly enlarged, and at present, more than 100 surrounding farmers are radiated, and the breeding area is more than 5000 mu, so that huge scale benefits, economic benefits and ecological benefits are generated, and the method has good development potential.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention in any way, and all simple modifications and equivalent variations of the above embodiment according to the technical spirit of the present invention are included in the protection scope of the present invention.