A kind of cultivation method of fern racemose algae

Abstract

The present invention provides a cultivation method for Pteris racemosa. The cultivation method involves cultivating Pteris racemosa in a water aquaculture area in different zones. Within the water aquaculture area, an area 0.2 to 0.4 meters above the water surface serves as a first zone, and other zones within the water aquaculture area serve as a second zone. In the first zone, the Pteris racemosa in the zone is secured by hanging cultivation: multiple hanging bases are secured on a support spanning the water aquaculture area, the hanging bases are sunk into the first zone, the Pteris racemosa are evenly suspended on the hanging bases, and first air stones are secured between the hanging bases. In the second zone, the Pteris racemosa in the zone is secured by using a support net frame cultivation method: the support net frame is placed at the bottom of the water aquaculture area, the support is fully covered with net frames, the Pteris racemosa are evenly secured on the net frames, and second air stones are secured to the net frames. The cultivation method provided by the present invention results in a higher yield of Pteris racemosa and better cultivation results.

Description

Technical Field

[0001] The present invention relates to the field of algae biology, and in particular to a cultivation method of Pteris racemosa. Background Art

[0002] Caulerpa racemesa is classified as a member of the Chlorophyta, Chlorophyceae, Siphoneae, Caulerpaceae, and Caulerpa genus. It is a cosmopolitan tropical species with numerous branches, bright green, 3 to 5 cm tall, and differentiated into erect and stoloniferous stems. Caulerpa racemesa is rich in dietary fiber, protein, and essential amino acids, low in fat, and abundant in minerals and vitamins. It has the effect of promoting qi circulation and relieving pain, and can treat various aches and pains caused by qi stagnation and blood stasis. It is a natural, high-quality health food ingredient. Caulerpa racemesa also plays an important role in aquaculture, serving as a feed additive to promote the growth of aquatic animals.

[0003] However, the current artificial cultivation of Pteris racemosus has the disadvantages of insufficient yield and large land occupation. Therefore, research and development of large-scale cultivation of Pteris racemosus with high yield, low cost and simple operation is one of the ideal ways to promote comprehensive resource conservation and recycling. Summary of the Invention

[0004] The present invention aims to address the current deficiencies in the technology for large-scale cultivation of Pteris racemosa by providing a method for cultivating Pteris racemosa. This method has the advantages of high yield, low cost, simple operation, and strong controllability. It greatly simplifies the technology and cost of large-scale artificial cultivation of seaweed in farms, and better meets market demand.

[0005] According to one aspect of the present invention, a cultivation method of bracken is provided, comprising cultivating the bracken in separate areas in an aquaculture water area, wherein an area 0.2 to 0.4 meters above the water surface in the aquaculture water area is a first area, and other areas in the aquaculture water area, excluding the first area, are a second area; in the first area, the bracken in the area is fixed by hanging and cultivating: a plurality of hanging bases are fixed on a support spanning the aquaculture water area, the hanging bases are sunk into the first area, the bracken is evenly suspended on the hanging bases, and first air stones are fixed between the hanging bases; in the second area, the bracken in the area is fixed by using a bracket net frame cultivation method: the bracket net frame is placed at the bottom of the aquaculture water area, the bracket is fully covered with the net frame, the bracken is evenly fixed on the net frame, and a second air stone is fixed on the net frame.

[0006] The present invention distinguishes different aquaculture water areas to cultivate racemose algae, effectively achieving comprehensive space utilization and creating a growth environment suitable for cultivating racemose algae. The racemose algae fixedly grown in the first area can obtain sufficient light, which is conducive to the growth and reproduction of racemose algae. Fixing the racemose algae in a hanging and suspended manner can ensure that the racemose algae grows in the first area throughout the cultivation process. Secondly, the racemose algae can be well fixed to avoid being affected by water flow and moving during daily cultivation, which causes the racemose algae to be affected by the external environment and change the distribution density. Ensuring uniform distribution between the air stone and the hanging base can ensure that each bundle of racemose algae is within the influence range of the air stone, ensuring sufficient carbon source. Fixing the racemose algae in a bracket net frame cultivation method is convenient for management. In the subsequent daily harvest, the bracket can be removed and harvested at one time to ensure that the growth of the racemose algae will not cover each other or block light. Secondly, the fixing effect is good. The bracket has a certain weight, which can ensure that the racemose algae grows in the second area and is not easy to move.

[0007] Preferably, the water depth in the aquaculture water area is 1.0 to 15 m, the water temperature is 22 to 30° C., the water salinity is 28.0 to 32.0‰, and the water pH value is 7.9 to 8.3.

[0008] When the aquaculture water meets the above-mentioned conditions, the yield of Pteris racemosa is higher and the cultivation results are more effective, effectively increasing the total annual production of Pteris racemosa and producing high-quality Pteris racemosa products. Throughout the aquaculture process, the water temperature in the aquaculture pond should be maintained between 22°C and 30°C. This is because temperature is crucial for the growth of Pteris racemosa. Excessively high or low water temperatures can restrict its growth. This may require an appropriate temperature to maintain normal enzyme activity within the Pteris racemosa, thereby ensuring biochemical reactions within the organism and preventing slow growth or even rot and death. Salinity affects the refraction of light in water, as well as the osmotic pressure balance of algal cells and the buoyancy experienced by the algae. Maintaining a salinity between 28% and 32% can increase the growth rate of Pteris racemosa. Furthermore, the growth characteristics of Pteris racemosa also vary with changes in water pH.

[0009] Preferably, in the first area, the racemose algae are planted at a distribution density of 4 to 5 bundles per cubic meter of water; and in the second area, the racemose algae are planted at a distribution density of 8 to 10 bundles per cubic meter of water.

[0010] In the first area, Brackenia racemosus is planted at a density of 4-5 clusters per cubic meter of water. This initial growth density in the first area ensures that the Brackenia racemosus will not block sunlight for each other or the Brackenia racemosus in the second area during the growing season, thus increasing the total number of Brackenia racemosus cultivated. Similarly, to ensure that the Brackenia racemosus cultivated in the second area receives sufficient light and nutrients, the Brackenia racemosus is planted at a density of 8-10 clusters per cubic meter of water in the second area. This prevents the Brackenia racemosus from competing for light and nutrients, resulting in poor yields, thereby further increasing the overall Brackenia racemosus cultivation yield.

[0011] Preferably, the initially planted racemose algae are algae strains with a main stem of 10 to 12 cm, and every two algae strains are fixed into a bundle.

[0012] Preferably, the average pore size of the first air stone in the first region is 0.5-1 μm; and the average pore size of the second air stone in the second region is 2-3 μm.

[0013] The first air stone serves as an aerator in the first zone, replenishing carbon dioxide from the aquaculture water as a carbon source for the algae. It also acts as a weight to maintain the initial spacing of the suspended substrates in the micro-flowing water, preventing them from agglomerating due to the impact of the water flow. This ensures that the algae maintain the initial production density set throughout the aquaculture process. The first and second air stones convert carbon dioxide into smaller bubbles, promoting its dissolution in the aquaculture water and providing an adequate carbon source for the algae's growth. The second air stone, installed in the second zone, not only serves as an aerator to replenish carbon dioxide but also creates bubbles that agitate the aquaculture water, creating a steady flow and promoting the diffusion of nutrients, thus promoting algae growth. The second air stone also creates water flow, which not only allows the algae to sway and evenly distribute light, but also helps to collect impurities, sludge, dead algae, and other debris from the pond bottom, making them easier to clean.

[0014] Preferably, calculated by mass percentage, the raw materials for preparing the second gas stone include: 50-60% red mud, 20-30% bentonite, 10-20% fly ash, 5-10% coal powder, and 1-5% foam stabilizer.

[0015] The second air stone made using the above raw materials has a loose and porous structure, and the formed pores are evenly distributed and interconnected, which can allow carbon dioxide to enter the aquaculture water area faster, thereby more effectively disturbing the water flow in the second area and providing nutrition for the growth of racemose algae.

[0016] Preferably, calculated by mass percentage, the raw materials for preparing the second gas stone include 57% red mud, 22% bentonite, 11.5% fly ash, 6% coal powder, and 3.5% foam stabilizer.

[0017] When the raw materials of the second air stone meet the above ratio, the pores of the second air stone are dense and three-dimensionally interconnected, which is conducive to the dispersion of carbon dioxide aeration while preventing excessive loss of momentum of the air flow, further disturbing the water flow, forming micro-flow water in the aquaculture water area, and promoting the flow of nutrients in the aquaculture water area.

[0018] Preferably, the preparation method of the second air stone includes the following steps: S1. Mixing the raw materials for preparing the second air stone, heating the mixture thus formed, heating it to a first insulation temperature at a heating rate of 8 to 12°C / min, the first insulation temperature is 780 to 850°C, and keeping it at the first insulation temperature for 20 to 40 minutes; S2. After S1 is completed, continue heating the mixture, heating it to a second insulation temperature at a heating rate of 3 to 5°C, the second insulation temperature is 1000 to 1150°C, and keeping it at the second insulation temperature for 45 to 90 minutes, so that the product obtained contains the second air stone.

[0019] In addition to the raw materials, the preparation method of the second air stone also affects the structural morphology of the second air stone. The present invention uses segmented temperature insulation when preparing the second air stone, and insulation is performed at the first insulation temperature and the second insulation temperature respectively to promote the reaction of the raw materials and decompose the gas. The channels of the gas discharge process are also retained to form pores, so that the pores are dense and three-dimensionally interconnected, achieving the effect of disturbing the water flow.

[0020] Preferably, the preparation method of the second air stone includes the following steps: S1. Mixing the raw materials for preparing the second air stone, heating the mixture thus formed, heating it to a first insulation temperature at a heating rate of 10°C / min, the first insulation temperature is 800°C, and keeping it at the first insulation temperature for 30 minutes; S2. After S1 is completed, continue heating the mixture, heating it to a second insulation temperature at a heating rate of 5°C, the second insulation temperature is 1100°C, and keeping it at the second insulation temperature for 60 minutes, so that the product obtained contains the second air stone.

[0021] In the above preparation method, the specific insulation time and heating rate are determined. The second air stone produced by this method has the characteristics of uniform pores and high strength. It can effectively convert carbon dioxide into smaller bubbles while ensuring that the bubbles still have momentum, further disturbing the water flow.

[0022] Preferably, micro-flow aquaculture is adopted in the aquaculture water area, with a daily water intake of 1 to 3 cubic meters of water.

[0023] The use of micro-water culture in breeding can supplement the trace elements needed by the racemose algae, thereby achieving a good growth state. The algae absorb the nutrients in the water and then excrete them, which can also purify the water and have a positive effect on the ecological environment. In addition, a small amount of water intake per day saves electricity consumed by pumping water.

[0024] Preferably, a breeding water area is set in the pond, the bottom of the pond is an inclined surface, and a water inlet and a drain are set on the side of the pond, the water inlet is set above the top of the inclined surface, and the drain is set above the bottom of the inclined surface, and in the breeding water area, the distance between the water inlet and the water surface is less than the distance between the drain and the water surface.

[0025] Preferably, purely carnivorous fish are released into the aquaculture water area.

[0026] The purpose of releasing purely carnivorous fish into the water is to use their feces to provide nutrients for algae. The feces of these higher-trophic, purely carnivorous fish are rich in organic fertilizer, which is essential for algae growth. Therefore, the cultivation method of Pteris racemosa in this invention does not require the addition of additional algal nutrients. Furthermore, the purely carnivorous fish do not consume the Pteris racemosa, which would result in unnecessary losses. Furthermore, cultivating purely carnivorous fish can increase economic benefits and promote the development of diversified aquaculture.

[0027] Preferably, the purely carnivorous fish is selected from at least one of groupers and snappers.

[0028] Groupers and snappers are both economically valuable benthic edible fish. They live on the bottom of the water and do not interfere with the growth space required by racemose algae, which can maintain ecological balance and achieve biological regulation. DETAILED DESCRIPTION

[0029] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0030] Example 1

[0031] Experimental group 1-1

[0032] 1. Prepare the breeding pond:

[0033] Prepare a 5m long, 4m wide, 1.5m deep, and 20m area 2A square outdoor cement pool was used as the aquaculture pond. Before aquaculture, the pool was cleaned and disinfected with bleach. Sand-filtered seawater was then added to bring the water level to 1.2 m. This created the aquaculture water area. The aquaculture water area was divided into two zones, designated as the first zone and the second zone, along the direction away from the water surface. Specifically, the area 0.2 to 0.4 meters from the water surface was designated the first zone, and the remaining areas within the aquaculture water area, excluding the first zone, were designated the second zone. Shallow aquaculture water temperatures can fluctuate significantly, while deep aquaculture water levels can lead to weak light levels in the lower layers, both of which are detrimental to algae growth.

[0034] The bottom of the pond is an inclined surface, with an inlet and outlet located on the side of the pond. The inlet is located above the top of the inclined surface, and the outlet is located above the bottom of the inclined surface. A drain pipe is inserted into the outlet. Multiple small holes with a diameter of 1 cm are drilled in the drain pipe at a distance of 1.2 m from the pond to maintain the water level at 1.2 m. In addition, in the aquaculture water area, the distance between the inlet and the water surface is less than the distance between the outlet and the water surface.

[0035] For the first five days of breeding, water quality indicators were tested daily at 9:00, 12:00, and 18:00. The main indicators monitored were temperature, pH, dissolved oxygen, and salinity. The breeding pond temperature should be no lower than 22°C and no higher than 30°C, the pH should be 7.9-8.3, the dissolved oxygen should be greater than 5 mg / L, the salinity should be 28-32‰, and the ammonia nitrogen content in the breeding water should be less than 0.2 mg / L.

[0036] 2. Cultivation of Pteridium racemosum:

[0037] The algae cultivation experiment started in early April. At this time, the water temperature was about 23.5℃, and no insulation measures were needed. At the beginning of the experiment, the initial average length of the racemose algae used was 10 cm, and every two algae strains were fixed into a bundle with a rope.

[0038] Suspension culture: Four 4.3m-long bamboo poles are evenly spaced across the pond. Ten suspension bases are evenly fixed to each pole, with the base submerged in the water and 25cm above the surface. A primary air stone with an average pore size of 0.7μm is fixed between each suspension base. A bundle of Pteris racemosa is secured to each suspension base with a cable tie, ensuring a planting density of four bundles per cubic meter of water in the first area.

[0039] ② Frame culture: The frame is 0.6m high and 0.8m wide and long. It is covered with 3cm mesh. Ties are evenly distributed across the frame, securing 10 bundles of Pteris racemosus to each frame. In the second zone, the density is 10 bundles per cubic meter of water. The frames are placed at the bottom of the pond, with the Pteris racemosus nestled in the middle water layer. The frames are spaced approximately 10cm apart. Two secondary air stones, with an average pore size of 2.5μm, are placed on each frame. These provide aeration, replenishing carbon dioxide, and creating a constant flow, promoting algae growth.

[0040] Among them, the first air stone and the second air stone used in this experimental group are both commercially available products. Moreover, during the cultivation experiment of Pteris racemosa, the first air stone and the second air stone are both connected to the carbon dioxide supply system. The carbon dioxide released into the breeding water area through the first air stone and the second air stone can serve as a carbon source for Pteris racemosa.

[0041] 3. Daily management:

[0042] If the maximum water temperature is higher than 28℃, cover the pond with a shade net to prevent excessive light and high water temperature for aquaculture; if the minimum water temperature is lower than 22℃, cover the pond with a 1.5-meter-high plastic shed above and around the pond to ensure that the minimum water temperature is not lower than 22℃, creating a more suitable temperature for the growth of aquaculture algae.

[0043] Three purely carnivorous fish were placed per cubic meter of water, for a total of 72 fish. Specifically, purple snappers were stocked at a size of 20-30 g per fish. A floating feed was fed once daily at 9:00 AM, in an amount sufficient for the purely carnivorous fish to consume within 5-10 minutes. An appropriate amount of algae-scraping snails, such as lychee snails and tower snails, were added to the aquaculture pond to scrape benthic microalgae and impurities from the pond walls, bottom, and support nets. Algae growth was monitored daily. If the pond bottom contained large amounts of fish feces, dead algae, and other debris, the water was vacuumed and replaced promptly. Micro-flow aquaculture was used throughout the aquaculture process, with no algae nutrients added, and natural sunlight was used.

[0044] In the middle and late stages of aquaculture, after the aquaculture water body stabilizes, water quality indicators are tested every five days to maintain the temperature at 22-30°C, pH at 7.9-8.3, dissolved oxygen greater than 5 mg / L, salinity at 28-32‰, and ammonia nitrogen in the water body less than 0.2 mg / L. In particular, the water temperature in the aquaculture water area is maintained at 26-30°C in spring and summer, and the water temperature in the aquaculture water area is maintained at 22-26°C in autumn and winter.

[0045] 4. Harvest:

[0046] Harvest Bracken regularly. When Bracken reaches a certain density, it needs to be harvested because its stems and leaves block each other, affecting its growth rate. Calculate the harvest yield. When the water temperature is 26°C to 29°C, harvest Bracken every three weeks to maintain a density of 4 to 5 clusters per cubic meter of water in the first area and 8 to 10 clusters per cubic meter of water in the second area. When the water temperature is 22°C to 26°C, harvest Bracken every four to five weeks to maintain a density of 4 to 5 clusters per cubic meter of water in the first area and 8 to 10 clusters per cubic meter of water in the second area.

[0047] During the one-year cultivation, the racemose algae were harvested 12 times in total.

[0048] Comparison group 1

[0049] This control group followed the same cultivation method as Experimental Group 1-1. The difference between this control group and Experimental Group 1-1 was that no cultivation was performed in the first area, and only cages were used in the second area. All other materials and cultivation methods were strictly consistent with Experimental Group 1-1.

[0050] Comparison group 2

[0051] This control group cultivated Pteris racemosa using the same cultivation method as Experimental Group 1-1. The difference between this control group and Experimental Group 1-1 was that the cultivation method in the first area was a rack-and-frame culture: the rack-and-frame was immersed in water and held 25 cm above the water surface. The rack was covered with 3 cm mesh nets, and Pteris racemosa was evenly distributed and fixed to the nets with tie wraps. The distribution density of Pteris racemosa in the first area was consistent with that in the first area of ​​Experimental Group 1-1. All other materials and cultivation methods were strictly consistent with those in Experimental Group 1-1.

[0052] Comparison group 3

[0053] This control group used the same cultivation method as Experimental Group 1-1. The only difference between this control group and Experimental Group 1-1 was that no air stones were used in the entire culture water area. All other materials and cultivation methods remained the same as Experimental Group 1-1.

[0054] Example 2

[0055] Experimental group 2-1

[0056] This experimental group cultured Pteris racemosus according to the culture method of Experimental Group 1-1. The difference between this experimental group and Experimental Group 1-1 is that the average temperature of the culture water area is between 22 and 35 ° C. The rest of the materials and culture methods are strictly consistent with Experimental Group 1-1.

[0057] Experimental group 2-2

[0058] This experimental group referred to the culture method of Pteris racemosus provided by Experimental Group 1-1 to cultivate Pteris racemosus. The difference between this experimental group and Experimental Group 1-1 is that the average temperature of the culture water area is between 17 and 30°C. The other materials and culture methods are strictly consistent with Experimental Group 1-1.

[0059] Example 3

[0060] Experimental group 3-1

[0061] This experimental group followed the same culture method as Experimental Group 1-1. The difference between this experimental group and Experimental Group 1-1 was that no carnivorous fish were introduced. All other materials and culture methods remained the same as Experimental Group 1-1.

[0062] Experimental group 3-2

[0063] This experimental group followed the same culture method as Experimental Group 1-1. The difference between this experimental group and Experimental Group 1-1 was the use of a different, purely carnivorous fish species: grouper. All other materials and culture methods remained the same as in Experimental Group 1-1.

[0064] Example 4

[0065] Experimental group 4-1

[0066] This experimental group followed the same cultivation method as that provided in Experimental Group 1-1. The difference between this experimental group and Experimental Group 1-1 was that the average pore size of the first air stone was 2.5 μm. All other materials and cultivation methods remained the same as those in Experimental Group 1-1.

[0067] Experimental group 4-2

[0068] This experimental group followed the same cultivation method as that provided in Experimental Group 1-1. The difference between this experimental group and Experimental Group 1-1 was that the average pore size of the second air stone was 0.7 μm. All other materials and cultivation methods remained the same as those in Experimental Group 1-1.

[0069] Experimental group 4-3

[0070] This experimental group referred to the cultivation method of Pteris racemosus provided by Experimental Group 1-1 to cultivate Pteris racemosus. The difference between this experimental group and Experimental Group 1-1 is that the second air stone used is a homemade air stone. In this experimental group, the specific preparation method of the second air stone is as follows:

[0071] S1. Calculated by mass percentage, the raw materials used to prepare the second gas stone include 57% red mud, 22% bentonite, 11.5% fly ash, 6% coal powder, and 3.5% foam stabilizer. The above raw materials are mixed, and the resulting mixture is heated to 1100°C at a heating rate of 10°C / min and kept at this temperature for 60 minutes. After the insulation period, the mixture is naturally cooled to obtain the product used as the second gas stone used in this experimental group.

[0072] Apart from the above differences, the rest of the materials and culture methods used in this experimental group were strictly consistent with those of experimental group 1-1.

[0073] Experimental group 4-4

[0074] This experimental group referred to the cultivation method of Pteris racemosus provided by Experimental Group 1-1 to cultivate Pteris racemosus. The difference between this experimental group and Experimental Group 1 is that the second air stone used is a homemade air stone. In this experimental group, the specific preparation method of the second air stone is as follows:

[0075] S1. The raw materials for preparing the second gas stone include, calculated by mass percentage, 57% red mud, 22% bentonite, 11.5% fly ash, 6% pulverized coal, and 3.5% foam stabilizer. The above raw materials are mixed and the resulting mixture is heated at a heating rate of 10°C / min to a first holding temperature of 800°C, and the mixture is held at the first holding temperature for 30 minutes;

[0076] S2. After S1 is completed, continue to heat the mixture, increase the temperature to the second insulation temperature at a heating rate of 10°C, the second insulation temperature is 1100°C, and keep it at the second insulation temperature for 60 minutes. After the insulation is completed, cool it naturally and use the product obtained as the second gas stone used in this experimental group.

[0077] Apart from the above differences, the rest of the materials and culture methods used in this experimental group were strictly consistent with those of experimental group 1-1.

[0078] Experimental groups 4-5

[0079] This experimental group referred to the cultivation method of Pteris racemosus provided by Experimental Group 1-1 to cultivate Pteris racemosus. The difference between this experimental group and Experimental Group 1-1 is that the second air stone used is a homemade air stone. In this experimental group, the specific preparation method of the second air stone is as follows:

[0080] S1. The raw materials for preparing the second gas stone include, calculated by mass percentage, 57% red mud, 22% bentonite, 11.5% fly ash, 6% pulverized coal, and 3.5% foam stabilizer. The above raw materials are mixed and the resulting mixture is heated at a heating rate of 10°C / min to a first holding temperature of 800°C, and the mixture is held at the first holding temperature for 30 minutes;

[0081] S2. After S1 is completed, continue to heat the mixture, increase the temperature to the second insulation temperature at a heating rate of 5°C, the second insulation temperature is 1100°C, and keep it at the second insulation temperature for 60 minutes. After the insulation is completed, cool it naturally and use the product obtained as the second gas stone used in this experimental group.

[0082] Apart from the above differences, the rest of the materials and culture methods used in this experimental group were strictly consistent with those of experimental group 1-1.

[0083] Test Example 1

[0084] Test subjects: Pteris racemosa before and after cultivation in Examples 1 to 3

[0085] Test method: The Pteris racemosus was weighed before cultivation and the harvested Pteris racemosus was also weighed to calculate the cultivation growth. The specific test results are shown in Table 1.

[0086] Table 1. Cultivation growth of Pteris racemosus in each experimental group (kg)

[0087]

[0088]

[0089] Test results:

[0090] According to the growth of Pteris racemosus shown in Table 1, the first zone of the aquaculture area was fixed with hanging cultivation, while the second zone was fixed with scaffolding and net-frame cultivation. In this case, the Pteris racemosus cultured in the first and second zones performed well. A comparison of the growth of Pteris racemosus cultured in Experimental Group 1-1, Comparative Group 1, and Comparative Group 2 shows that in Comparative Group 1, only scaffolding and net-frame cultivation was used in the second zone, with no cultivation in the first zone. This resulted in poor space utilization in the aquaculture zone, and overall lower growth of Pteris racemosus culture. In Comparative Group 2, scaffolding and net-frame cultivation was used in both the first and second zones. The planting density and air stone arrangement in the first zone of Comparative Group 2 were identical to those in the first zone of Experimental Group 1-1. However, the overall growth in Comparative Group 2 was lower than that in Experimental Group 1-1. This is presumably because the scaffolding and net-frame cultivation in the first zone blocked significant sunlight, resulting in insufficient light for the Pteris racemosus in the second zone and slower growth. Compared with experimental group 1-1, in the entire aquaculture water area of ​​comparison group 3, air stones were not used. The carbon source in the aquaculture water area was supplemented by the dissolution of carbon dioxide in the air. The entire aquaculture water area fell into the problem of insufficient carbon source. The growth of the racemose algae in the first and second areas was relatively slow, and the growth rate was low.

[0091] According to the growth rates of Pteris racemosa shown in Table 1, Pteris racemosa in the first and second zones thrived when the water temperature in the aquaculture area remained between 22 and 30°C. Comparing the growth rates of experimental groups 1-1, 2-1, and 2-2 reveals that in group 1, summer daytime temperatures easily reached 30 to 35°C. Without cooling measures, the high temperatures in the Pteris racemosa caused enzyme inactivation, leading to rotting and death. In group 2, winter nighttime temperatures easily reached 17 to 22°C. Without insulation measures, the low temperatures reduced enzyme activity and slowed growth. Therefore, maintaining a water temperature of 22 to 30°C in the aquaculture area ensures normal biochemical reactions and optimal growth.

[0092] Analysis of the test results for Experimental Groups 1-1, 3-1, and 3-2 in Table 1 indicates that the introduction of Lutjanus ruber (Lutjanus ruber) significantly boosted the growth of Pteris racemosa. Comparing Experimental Group 3-1 with Experimental Groups 1-1 and 3-2, the absence of carnivorous fish in Experimental Group 3-1 resulted in insufficient nutrients in the aquaculture water, leading to lower Pteris racemosa growth than in Experimental Groups 1-1 and 3-2. Therefore, the introduction of carnivorous fish can increase the growth of Pteris racemosa in aquaculture.

[0093] Comparing the growth rates of Pteris racemosa in Experimental Group 1-1 and Experimental Groups 4-1 to 4-5 in Table 1 reveals that the average pore size of the first air stone in Experimental Group 1-1 is 2.5 μm, resulting in larger bubbles. This slows the dissolution of carbon dioxide in the aquaculture water, presumably due to insufficient carbon source for the Pteris racemosa in the first area, leading to slow growth. When the average pore size of the first air stone is in the 0.5-1 μm range, carbon dioxide gas is converted into smaller bubbles, promoting its dissolution in the aquaculture water and providing a sufficient carbon source for the growth of Pteris racemosa. The average pore size of the second air stone in Experimental Group 4-2 is 0.7 μm, and the bubbles generated are smaller than those in Experimental Group 1-1, resulting in less ability to disrupt water flow. In the middle and late stages of aquaculture, the pores of the second air stone are even clogged with debris. When the average pore size of the second air stone is between 2 and 3 μm, it can drive the water flow, which can not only make the algae swing and receive light evenly, but the flowing water can also cause impurities, sludge, dead algae and other dirt at the bottom of the pool to accumulate together, making it easier to clean.

[0094] Comparing the test results (Table 1) for Experimental Group 1-1 and Experimental Groups 4-3 to 4-5) reveals that the use of a commercially available second air stone in Experimental Group 1-1 increased the yield of Pteris racemosa, while the use of a homemade second air stone in Experimental Groups 4-3 to 4-5 further enhanced the growth of Pteris racemosa. The pores formed in the homemade second air stone are dense and interconnected in three dimensions, effectively retaining the momentum of carbon dioxide entering the aquaculture area, further disrupting the water flow in the second area and providing sufficient nutrients for the growth of Pteris racemosa. Among them, the second air stone prepared in Experimental Group 4-5 achieved the best water flow disturbance, resulting in the greatest increase in the growth of Pteris racemosa and the best aquaculture results.

[0095] Test Example 2

[0096] Participants: Experimental group 1-1 pure carnivorous fish before and after breeding

[0097] Test method: The pure carnivorous fish were weighed before and after breeding to calculate the breeding growth. The specific test results are shown in Table 2.

[0098] Table 2. Growth of pure carnivorous fish in each experimental group (kg)

[0099] Group Fish species Initial weight End weight Growth Experimental group 1-1 Purple Snapper 1.786 30.9 29.114

[0100] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A method for cultivating Pteridium racemosa, characterized in that: The following operations are included: Cultivating the racemose algae in a breeding water area in different areas, wherein an area 0.2 to 0.4 meters from the water surface in the breeding water area is a first area, and other areas in the breeding water area except the first area are second areas; In the first area, the Pteris racemosa in the area is fixed by hanging and cultivating: a plurality of hanging substrates are fixed on a support spanning above the aquaculture area, the hanging substrates are sunk into the first area, the Pteris racemosa is evenly suspended on the hanging substrates, and first air stones are fixed between the hanging substrates, wherein the average pore size of the first air stones in the first area is 0.5-1 μm; in the first area, the Pteris racemosa is planted at a distribution density of 4-5 bundles per cubic meter of water; In the second area, the racemose algae are fixed in the area by using a support net frame cultivation method: the support net frame is placed at the bottom of the aquaculture water area, the support net frame is fully covered with the net frame, the racemose algae are evenly fixed on the net frame, and a second air stone is fixed on the net frame, wherein the average pore size of the second air stone in the second area is 2-3 μm; in the second area, the racemose algae are planted at a distribution density of 8-10 bundles per cubic meter of water; Calculated by mass percentage, the raw materials for preparing the second gas stone include: 50-60% red mud, 20-30% bentonite, 10-20% fly ash, 5-10% coal powder, and 1-5% foam stabilizer; The preparation method of the second air stone includes the following steps: S1. Mixing the raw materials for preparing the second air stone, heating the thus formed mixture, heating it to a first insulation temperature at a heating rate of 8 to 12°C / min, the first insulation temperature is 780 to 850°C, and keeping it at the first insulation temperature for 20 to 40 minutes; S2. After the completion of S1, continuing to heat the mixture, heating it to a second insulation temperature at a heating rate of 3 to 5°C, the second insulation temperature is 1000 to 1150°C, and keeping it at the second insulation temperature for 45 to 90 minutes, so that the product obtained contains the second air stone.

2. The cultivation method of Pteridium racemosa according to claim 1, characterized in that: The aquaculture water area has a water depth of 1.0~1.5m, a water temperature of 22~30°C, a water salinity of 28.0~32.0‰, and a water pH value of 7.9~8.

3.

3. The cultivation method of Pteridium racemosa as claimed in claim 1, characterized in that: In the aquaculture water area, micro-flow aquaculture is adopted, and the daily water intake is 1 to 3 cubic meters of water.

4. The cultivation method of Pteridium racemosa as claimed in claim 3, characterized in that: The aquaculture water area is set in a pond, the bottom of the pond is an inclined surface, and a water inlet and a drain are set on the side of the pond. The water inlet is set above the top of the inclined surface, and the drain is set above the bottom of the inclined surface. In addition, in the aquaculture water area, the distance between the water inlet and the water surface is smaller than the distance between the drain and the water surface.

5. The cultivation method of Pteridium racemosa as claimed in claim 1, characterized in that: Purely carnivorous fish are released into the aquaculture water area.

6. The cultivation method of Pteridium racemosa as claimed in claim 5, characterized in that: The purely carnivorous fish is selected from at least one of grouper and Lutjanidae fish.

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