Fertilizing method for promoting growth of gulfweed seedlings

Abstract

The invention relates to a fertilization method for promoting growth of gulfweed seedlings, which comprises the following steps: step S1: placing the gulfweed seedlings to enter a dormant period in a nursery pond for shading and aeration culture, applying a first nutrient solution into the nursery pond, and gradually increasing the application frequency; s2, qualified gulfweed seedlings are selected and transferred to a low-flow-velocity sea area to be cultured, and a second nutrient solution is regularly applied; s3, qualified gulfweed seedlings are selected and transferred to a high-flow-velocity sea area to be cultured until the average length of the gulfweed seedlings exceeds 10 cm, and a third nutrient solution or a second nutrient solution is applied for culture; or S3, a third nutrient solution is applied to the low-flow-velocity sea area in the step S2 to be cultured until the average length of the sargassum seedlings exceeds 10 cm. According to the fertilization method for promoting growth of the gulfweed seedlings, the growth speed and stress resistance of the seedlings can be effectively improved, the dormancy period is shortened, and the survival rate of the seedlings is increased.

Description

Technical Field

[0001] The invention relates to the field of seaweed cultivation, in particular to a fertilization method for promoting the growth of Sargassum seedlings. Background Art

[0002] Sargassum, which belongs to the genus Sargassum, the order Fucales, the family Sargassum, and the phylum Phaeophyta, is a large algae with important economic value. It not only plays an important role in the ecosystem, but also has a wide range of applications in industry, agriculture, food, medicine, etc. Under the dual influence of global climate change and human overfishing, offshore Sargassum beds tend to degenerate and shrink, and Sargassum resources are facing threats. Artificial large-scale cultivation through sexual reproduction has become an effective way to meet human demand for Sargassum resources and protect ecological resources.

[0003] The breeding season of Sargassum is usually in the high temperature period of summer. The seedlings bred by Sargassum can grow to 2 cm in 1 to 1.5 months. The growth and development speed of the seedlings at this stage is normal and does not require too much human intervention. However, after growing to 2 cm, Sargassum will enter a long slow growth stage (commonly known as dormancy). The seedlings at this stage generally need to go through a dormancy period of 5 to 7 months until they grow to more than 5 cm, and their growth rate will return to normal. During the slow growth stage, especially in early summer, the growth rate of Sargassum will slow down, and then it may enter a dormant state until the environmental conditions improve, such as when the temperature drops, and they will resume growth. For example, the dormancy period of Sargassum can be as long as 6 months, from May to November.

[0004] In addition, due to the long duration of the dormancy period, the dormant seedlings are weak and have poor stress resistance, resulting in a low survival rate of seedlings; for example, the seedlings are covered with mud and sand, which makes them unable to photosynthesize and die. Another example is that the seedlings have insufficient root fixation and are easily detached from the seedling rope / seedling curtain during the longline cultivation method at sea (the seedlings have not yet developed air sacs and cannot float, so the fallen seedlings generally sink to the bottom of the water and die due to the inability to photosynthesize). Therefore, the long dormancy period and low survival rate of seedlings are a technical bottleneck in the current large-scale artificial cultivation. Summary of the invention

[0005] Based on this, the purpose of the present invention is to provide a fertilization method for promoting the growth of Sargassum seedlings, which can effectively increase the growth rate and stress resistance of the seedlings, shorten the dormancy period, and increase the survival rate of the seedlings.

[0006] A fertilization method for promoting the growth of Sargassum seedlings comprises the following steps:

[0007] Step S1: Cultivation in a nursery pond: placing Sargassum seedlings that are about to enter a dormant period in a nursery pond for shading and aeration cultivation, and periodically applying a first nutrient solution containing a first nutrient component to the nursery pond and gradually increasing the frequency of application; the first nutrient component includes 0.21-0.5 g / L basic nutrients, 8.5-22 mg / L trace elements, 0.68-1.75 mg / L vitamins, and 0.10-0.24 mg / L plant growth hormones;

[0008] Step S2: Cultivation in low-velocity sea area: selecting the Sargassum seedlings with a length of more than 3 cm from the nursery pond, transferring them to a low-velocity sea area for cultivation, and regularly applying a second nutrient solution containing a second nutrient component to the low-velocity sea area for sea area cultivation; the second nutrient component includes 0.35-0.83 g / L basic nutrients, 10-46 mg / L trace elements, 0.8-2.8 mg / L vitamins and 0.0125-0.0233 mg / L plant growth hormones;

[0009] Step S3: Cultivation in a high-velocity sea area: selecting the Sargassum seedlings with a length exceeding 5 cm from the low-velocity sea area and transferring them to a high-velocity sea area for cultivation until the average length of the Sargassum seedlings exceeds 10 cm, during which a third nutrient solution containing a third nutrient component is regularly applied to the high-velocity sea area for sea area cultivation; the third nutrient component includes basic nutrients, trace elements and plant growth hormones; or the second nutrient solution containing the second nutrient component is regularly applied to the high-velocity sea area for sea area cultivation;

[0010] Or step S3: secondary cultivation in low-flow sea area: regularly applying the third nutrient solution containing the third nutrient component to the low-flow sea area in step S2 for sea area cultivation until the average length of the Sargassum seedlings exceeds 10 cm; the third nutrient component consists of 0.63-1.13 g / L basic nutrients, 33.13-74.33 mg / L trace elements and 0.0063-0.0133 mg / L plant growth hormones.

[0011] The inventor has found that Sargassum is a wave-loving plant. In seas with larger winds and waves, the exchange of air and water is usually more frequent, and Sargassum grows better. Based on this characteristic of Sargassum, the technology of the present invention divides the cultivation of Sargassum seedlings into three stages. The first breeding stage is cultivation in the nursery pond, the second stage is cultivation in low-velocity seas, and the third stage is cultivation in high-velocity seas or secondary cultivation in low-velocity seas. The Sargassum seedlings in the nursery pond cultivation stage are weak and need to be intensively cultivated in the pond. Nutrition is applied to prompt them to break the dormant state, make the seedlings more robust, and increase the fixation of the pseudo-roots. Although the Sargassum seedlings cultivated in the nursery pond have undergone certain intensive cultivation, their fixation strength and stress resistance are not enough to be directly cultivated in high-velocity seas. Therefore, they need to be further intensively cultivated in low-velocity seas to further strengthen individual stress resistance and pseudo-root fixation. The Sargassum seedlings that have been further strengthened in the third stage can be transferred to a high-velocity sea area for cultivation to further strengthen the stress resistance of the Sargassum and make it grow better; or for economic cost considerations, avoid cultivation in a high-velocity sea area with a higher flow rate, faster water exchange, and the need to further increase the concentration of nutrients to ensure the fertilizer efficiency of the Sargassum seedlings. It can also be selected to continue cultivation in the low-velocity sea area of ​​the second stage until the average length of the Sargassum seedlings exceeds 10 cm, which is considered to be the end of the dormancy period. A fertilization method for promoting the growth of Sargassum seedlings of the present invention applies an appropriate amount of nutrient components containing plant growth hormones during the cultivation process of the Sargassum seedlings during the dormancy period to prompt the Sargassum seedlings to break the dormancy state, accelerate their growth, shorten the dormancy period, make their body more robust, and strengthen their rhizoid fixation ability, thereby effectively improving the stress resistance and survival rate of the seedlings, which is of great significance for realizing large-scale artificial cultivation of Sargassum.

[0012] Further, the plant growth hormone in the first nutrient component includes 0.01-0.02 mg / L6-BA cytokinin, 0.01-0.02 mg / LGA3 gibberellin and 0.1-0.2 mg / L brassinolide; the plant growth hormone in the second nutrient component includes 0.0063-0.01 mg / L6-BA cytokinin and 0.0063-0.013 mg / LGA3 gibberellin; the plant growth hormone in the third nutrient component is 0.0063-0.0133 mg / L6-BA cytokinin. The inventors have found that the Sargassum seedlings in the nursery pond cultivation stage have officially entered the dormant period, and three plant growth hormones need to be stimulated together to achieve a better growth-promoting effect. Among them, the main effect of gibberellin is to break the dormant state, and the main effects of cytokinin and brassinolide are to promote the growth of seedlings. The three together have the best effect. The length of Sargassum seedlings cultivated in low-velocity sea areas exceeds 3 cm. The seedlings at this stage are no longer sensitive to the stimulation of brassinolide, and excessive brassinolide concentration will inhibit the growth of Sargassum. Therefore, for environmental protection and economic considerations, brassinolide is removed from the second nutrient component. The Sargassum seedlings that have finished cultivation in low-velocity sea areas are basically out of dormancy. At this stage, the fixation strength of the rhizoids of the Sargassum seedlings and the stress resistance of the seedlings are qualitatively improved, and the survival rate is also significantly increased. At this time, gibberellins have limited effect on promoting the growth of Sargassum, and only cytokinins can effectively promote the growth of seedlings. Therefore, for environmental protection and economic considerations, only cytokinins are retained in the plant growth hormones in the third nutrient component. The limitation of the composition and concentration range of the above-mentioned plant growth hormones is most conducive to the growth of Sargassum seedlings.

[0013] Furthermore, the basic nutrients include KNO3, KH2PO4, MgSO4·7H2O, and NaNO3; the trace elements include FeSO4·7H2O, ZnSO4·7H2O, CuSO4·5H2O, MnSO4·7H2O, H3BO3, and Na2MoO4·10H2O; and the vitamins include vitamin B1, vitamin B12, vitamin C, and vitamin E.

[0014] Furthermore, the first nutrient solution is prepared by adding the first nutrient component to sterile seawater, and refrigerating it after it is fully dissolved; the second nutrient solution is prepared by adding the second nutrient component to the precipitated and filtered seawater and fully dissolving it; the third nutrient solution is prepared by adding the third nutrient component to the precipitated and filtered seawater and fully dissolving it.

[0015] Furthermore, the specific method of gradually increasing the application frequency in the seedling pool cultivation in step S1 is:

[0016] (1) Phase 1: Apply the first nutrient solution once a day;

[0017] (2) Second stage: applying the first nutrient solution twice a day; the interval between the two applications is 5 to 6 hours;

[0018] (3) The third stage: applying the first nutrient solution three times a day; the interval between each application is 3.5 to 4 hours;

[0019] The first stage, the second stage and the third stage are divided into time periods, and the durations thereof are adjusted according to the growth status of the Sargassum seedlings and other algae in the nursery pond.

[0020] In the nursery pond cultivation stage in step S1, since the nursery pond is a closed breeding space, the utilization of nutrients is more complete and effective than breeding in the sea. If the fertilizer concentration is too high or the amount of fertilizer is too large at the beginning, it is easy to breed weeds and algae. The weeds and algae have strong vitality and can quickly occupy the growth space and nutrients of Sargassum, resulting in seedling failure. Therefore, in order to strictly prevent the breeding and excessive growth of weeds such as Enteromorpha, Ulva, and reef film, the frequency of application of the first nutrient solution needs to be gradually increased in stages during the nursery pond cultivation stage.

[0021] Furthermore, the low-flow sea area cultivation in step S2 and the high-flow sea area cultivation in step S3 are both carried out by longline cultivation.

[0022] Furthermore, the method for applying the second nutrient solution is as follows: prepare a plurality of small bottles, each of which is provided with a plurality of small holes; quickly dispense the second nutrient solution into the small bottles and seal them; weight the small bottles with heavy objects, and then hang the bottles under the seedling rope / seedling curtain or breeding cable at even intervals; and regularly replace the second nutrient solution in the small bottles.

[0023] Furthermore, the method for applying the third nutrient solution is as follows: prepare a number of small bottles, each of which is provided with a number of small holes; quickly dispense the third nutrient solution into the small bottles and seal them; weight the small bottles with heavy objects, and then hang the bottles under the seedling rope / seedling curtain or breeding cable at even intervals; and regularly replace the third nutrient solution in the small bottles.

[0024] Furthermore, the nursery pond needs to be covered with a sunshade net to keep the light intensity no more than 20,000 lx and the aeration volume no less than 10 L / min / m 3 Aeration culture. Ensure water-gas exchange and water fluidity in the culture pond, and control the growth and overgrowth of algae such as Enteromorpha.

[0025] Furthermore, the low-flow sea area is a sea area with smooth water exchange, an average water flow velocity not exceeding 3m / s, a water depth not exceeding 10m, a water transparency not less than 1m, and excellent water quality;

[0026] Furthermore, the high-flow sea area is a sea area with smooth water exchange, an average water flow velocity of 3 to 5 m / s, a water depth not exceeding 10 m, a water transparency of not less than 1 m, and excellent water quality.

[0027] In order to better understand and implement the present invention, the present invention is described in detail below in conjunction with embodiments. DETAILED DESCRIPTION

[0028] It should be clear that the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the embodiments of the present application.

[0029] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the embodiments of the present application. The singular forms of "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0030] In the description of this application, it should be understood that the terms "first", "second", "third", etc. are only used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence, nor can they be understood as indicating or implying relative importance. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0031] In addition, in the description of this application, unless otherwise specified, "plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the associated objects are in an "or" relationship.

[0032] A fertilization method for promoting the growth of Sargassum seedlings comprises the following steps:

[0033] Step S1: Cultivation in a nursery pond: 1-1.5 month old Sargassum seedlings are placed in a nursery pond for 24-30 days under shading and aeration, during which a first nutrient solution containing a first nutrient component is regularly applied to the nursery pond and the application frequency is gradually increased.

[0034] Furthermore, the first nutrient component and the content of each component in the first nutrient solution are shown in Table 1 below; the first nutrient component and the content of each component in the first nutrient solution in Table 1 are suitable for a seedling pond with a width of 3m, a length of 6m, and a culture water depth of 0.6m; the preparation method of the first nutrient solution is: add the first nutrient component in Table 1 to 10-12L sterile seawater, and store it in a refrigerator at 2-8°C after it is fully dissolved.

[0035] Furthermore, in order to ensure the water-gas exchange and water fluidity of the nursery pond, the nursery pond needs to be aerated, and the aeration rate is not less than 10L / min / m 3 .

[0036] Furthermore, in order to control the proliferation and overgrowth of algae such as Enteromorpha, the nursery pond needs to be covered with a sunshade net to keep the light intensity no more than 20,000 lx.

[0037] Furthermore, the step S1 of the fertilization method for promoting the growth of Sargassum seedlings of the present invention also controls the proliferation and excessive growth of algae such as Enteromorpha by gradually increasing the application frequency of the first nutrient solution in stages, changing water, and cleaning up algae. The specific process is as follows:

[0038] (1) The first stage: applying the first nutrient solution once every morning; specifically, taking 1 to 2 L of the prepared first nutrient solution, diluting it 4 to 5 times with the sterile seawater, and evenly spraying it in the nursery pond; changing the water in the nursery pond 10 to 12 hours after application, with the daily water change amount being 1 / 2 of the water body; and promptly cleaning the growing algae such as Enteromorpha during the culture period.

[0039] (2) The second stage: applying the first nutrient solution once in the morning and once in the afternoon every day, with an interval of 5 to 6 hours between the two applications; specifically, taking 1 to 2 L of the prepared first nutrient solution, diluting it 4 to 5 times with the sterile seawater, and evenly spraying it in the nursery pond; 6 to 8 hours after the second application, changing the water in the nursery pond, with the daily water replacement amount being 1 / 2 of the water body.

[0040] (3) The third stage: applying the first nutrient solution once in the morning, noon and afternoon every day, with the interval between each application being 3.5 to 4 hours; taking 1 to 2 L of the prepared first nutrient solution, diluting it 4 to 5 times with the sterile seawater, and evenly spraying it in the nursery pond; changing the water in the nursery pond 5 to 6 hours after the third application, with the daily water replacement amount being 1 / 2 of the water body.

[0041] (4) Cultivating the Sargassum seedlings until the average length of the Sargassum seedlings exceeds 3 cm, thereby ending the cultivation in the nursery pond.

[0042] Furthermore, the first stage, the second stage and the third stage are divided by time, and the duration thereof is adjusted according to the growth status of the Sargassum seedlings and miscellaneous algae in the nursery pond.

[0043] Table 1

[0044]

[0045] Step S2: Cultivation in low-velocity sea area: The Sargassum seedlings with a length of more than 3 cm are selected from the nursery pond and transferred to a low-velocity sea area for cultivation using a longline cultivation method for 30 to 40 days. During this period, a second nutrient solution containing a second nutrient component is regularly applied to the low-velocity sea area for sea area cultivation.

[0046] Furthermore, the low-flow sea area is a sea area with smooth water exchange, an average water flow velocity not exceeding 3m / s, a water depth not exceeding 10m, a water transparency not less than 1m, and excellent water quality.

[0047] Furthermore, the second nutrient components and the content of each component in the second nutrient solution are shown in Table 2 below; the preparation method of the second nutrient solution is: add the second nutrient components in Table 2 to 30 to 32 L of precipitated and filtered seawater to fully dissolve.

[0048] Furthermore, the method for applying the second nutrient solution is as follows: prepare several plastic vials with a capacity of more than 600 ml, and pierce 80 to 100 small holes on the plastic vials with a small needle; quickly dispense the second nutrient solution into the plastic vials and seal them, each of which contains 500 to 600 ml of the second nutrient solution; weigh the plastic vials with heavy objects such as small stones, and then hang the vials evenly at intervals 15 to 20 cm below the seedling rope / seedling curtain or aquaculture cable; replace the second nutrient solution in the plastic vials every 6 to 7 days. Cultivate until the average length of the Sargassum seedlings exceeds 5 cm, and end the cultivation in the low-velocity sea area.

[0049] Table 2

[0050]

[0051] Step S3: Cultivation in high-velocity sea areas: selecting the Sargassum seedlings with a length exceeding 5 cm from the low-velocity sea area, transferring them to the high-velocity sea area, and cultivating them by the longline cultivation method until the average length of the Sargassum seedlings exceeds 10 cm, and terminating the cultivation in the high-velocity sea area. During this period, the third nutrient solution containing the third nutrient component is regularly applied to the high-velocity sea area for sea area cultivation, or the second nutrient solution containing the second nutrient component is regularly applied to the high-velocity sea area according to the method of applying the second nutrient solution for sea area cultivation.

[0052] Furthermore, the high-flow sea area is a sea area with unobstructed water exchange, an average water flow velocity not exceeding 3 to 5 m / s, a water depth not exceeding 10 m, a water transparency not less than 1 m, and excellent water quality.

[0053] Furthermore, the third nutrient component and the content of each component in the third nutrient solution are shown in Table 3 below; the preparation method of the third nutrient solution is: add the third nutrient component in Table 3 to 30 to 32 L of precipitated and filtered seawater to fully dissolve.

[0054] Furthermore, the method for applying the third nutrient solution is as follows: prepare several plastic bottles with a capacity of more than 600 ml, and pierce 80 to 100 small holes on the plastic bottles with a small needle; quickly dispense the second nutrient solution into the plastic bottles and seal them, each of the plastic bottles containing 500 to 600 ml of the second nutrient solution; weight the plastic bottles with heavy objects such as small stones, and then hang the bottles at even intervals 15 to 20 cm below the seedling rope / seedling curtain or breeding cable; the second nutrient solution in the plastic bottles is replaced every 6 to 7 days.

[0055] Table 3

[0056]

[0057] Or step S3: secondary cultivation in low-flow sea area: regularly apply the third nutrient solution containing the third nutrient component to the low-flow sea area in step S2 according to the third nutrient solution application method to carry out sea area cultivation until the average length of the Sargassum seedlings exceeds 10 cm.

[0058] Example 1

[0059] The preparation method of the first nutrient solution of this embodiment is: add the first nutrient component in Table 1 into 10L sterile seawater, and store it in a refrigerator at 2-8°C after it is fully dissolved.

[0060] The method for preparing the second nutrient solution of this embodiment is: adding the second nutrient component in Table 2 to 30 L of seawater after sedimentation and filtration to fully dissolve.

[0061] The preparation method of the third nutrient solution of this embodiment is: add the third nutrient component in Table 3 into 30L of seawater after sedimentation and filtration to fully dissolve.

[0062] The Sargassum in this embodiment is Sargassum wei'sii, the seedling pond is a cement pond of 3×6×1.5m, and the culture water depth is 0.6m; a fertilization method for promoting the growth of Sargassum seedlings in this embodiment includes the following steps:

[0063] Step S1: Cultivation in a nursery pond: Select the one-month-old Sargassum wei'sii seedlings and place them in the nursery pond for 24 days under light-shading and aeration. The water depth is 60 cm and the aeration rate is 20 L / min / m 3 , and at the same time, a sunshade net is set up for the nursery pool so that the internal light intensity does not exceed 20000lx; the first nutrient solution containing the first nutrient component is regularly applied to the nursery pool, and the application frequency of the first nutrient solution is gradually increased in stages, and water is changed and algae are cleaned. The specific process is as follows:

[0064] (1) Day 1 to Day 7: Apply the first nutrient solution once at 8:00 a.m. every day; specifically, take 1.5 L of the prepared first nutrient solution, dilute it 5 times with sterile seawater, and evenly sprinkle it on the nursery pond; change the water in the nursery pond at 20:00 p.m. every day, and the amount of water changed is 1 / 2 of the water body; during this period, clean up the growing algae such as Enteromorpha in time.

[0065] (2) Days 7 to 14: Apply the first nutrient solution once at 8:00 a.m. and 14:00 p.m. every day; take 1.5 L of the prepared first nutrient solution, dilute it 5 times with sterile seawater, and evenly sprinkle it in the nursery pond; change the water in the nursery pond at 21:00 p.m. every day, and the amount of water changed is 1 / 2 of the water body.

[0066] (3) Days 14 to 24: Apply the first nutrient solution once at 8:00 a.m., 12:00 p.m., and 16:00 p.m. every day; Take 1.5 L of the prepared first nutrient solution, dilute it 5 times with the sterile seawater, and evenly sprinkle it in the nursery pond; Change the water in the nursery pond at 21:00 p.m. every day, and the amount of water changed is 1 / 2 of the water body.

[0067] (4) The cultivation in the nursery pond is terminated. The average length of the Sargassum weiyi seedlings after the cultivation in the nursery pond is 3.5 cm.

[0068] Step S2: Cultivation in low-velocity sea area: selecting the Sargassum wei'sii seedlings with a length of more than 3 cm from the nursery pond, transferring them to a low-velocity sea area in Baisha Town, Xuwen County, Zhanjiang City, and cultivating them by longline cultivation for 30 days, wherein the average water flow velocity in the low-velocity sea area is 2 m / s, the average water depth is 4 m, and the water transparency is 3 m; regularly applying the second nutrient solution containing the second nutrient component to the low-velocity sea area for sea area cultivation, and the application method is as follows: preparing 32 plastic vials with a capacity of more than 600 ml, and piercing 80 small holes on the plastic vials with a small needle; quickly dispensing the second nutrient solution into the plastic vials and sealing them, wherein each of the plastic vials contains 500 ml of the second nutrient solution; the plastic vials are weighted with heavy objects such as small stones, and then evenly tied to the seedling rope / seedling curtain or the culture cable 15 cm below; the second nutrient solution in the plastic vials is replaced once every 7 days; during this period, the attached Enteromorpha, Ulva, silt, etc. are cleaned up in time. The average length of the Sargassum wei'sii seedlings after the cultivation in the low-flow sea area exceeds 5.2 cm.

[0069] Step S3: Cultivation in high-velocity sea area: selecting the Sargassum wei'sii seedlings with a length of more than 5 cm from the low-velocity sea area, transferring them to a high-velocity sea area in Baisha Town, Xuwen County, Zhanjiang City, and cultivating them by longline cultivation for 35 days, wherein the water velocity in the high-velocity sea area is 4.2 m / s, the average water depth is 8 m, and the water transparency is 3 m; regularly applying the third nutrient solution containing the third nutrient component to the high-velocity sea area for sea area cultivation, and the application method is as follows: preparing 33 plastic vials with a capacity of more than 600 ml, and piercing 80 small holes on the plastic vials with a small needle; quickly dispensing the third nutrient solution into the plastic vials and sealing them, each of the plastic vials containing 500 ml of the third nutrient solution; the plastic vials are weighted with heavy objects such as small stones, and then evenly tied to the seedling rope / seedling curtain or aquaculture cable 15 cm below; the third nutrient solution in the plastic vials is replaced once every 7 days. During this period, the attached Enteromorpha, Ulva, silt, etc. are cleaned in time. The average length of the Sargassum wei's seedlings after the high-velocity sea area cultivation is more than 11.3 cm, the body is strong, the rhizoids have strong fixation, and good stress resistance, and can be transferred to the traditional cultivation sea area for cultivation.

[0070] Example 2

[0071] The preparation method of the first nutrient solution of this embodiment is: add the first nutrient component in Table 1 into 11 L of sterile seawater, and store it in a refrigerator at 2-8° C. after it is fully dissolved.

[0072] The method for preparing the second nutrient solution of this embodiment is: adding the second nutrient component in Table 2 to 30 L of seawater after sedimentation and filtration to fully dissolve.

[0073] The preparation method of the third nutrient solution of this embodiment is: add the third nutrient component in Table 3 into 30L of seawater after sedimentation and filtration to fully dissolve.

[0074] The Sargassum in this embodiment is Sargassum mossoni, and the nursery pond is a cement pond of 3×6×1.2 m. A fertilization method for promoting the growth of Sargassum seedlings in this embodiment includes the following steps:

[0075] Step S1: Cultivation in a nursery pond: 1.5-month-old Sargassum mossoni seedlings were selected and placed in the nursery pond for 24 days under light-shading and aeration conditions. The water depth was 60 cm and the aeration rate was 28 L / min / m 3 , and at the same time, a sunshade net is set up for the nursery pool so that the internal light intensity does not exceed 20000lx; the first nutrient solution containing the first nutrient component is regularly applied to the nursery pool, and the application frequency of the first nutrient solution is gradually increased in stages, and water is changed and algae are cleaned. The specific process is as follows:

[0076] (1) Days 1 to 7: Apply the first nutrient solution once at 8:00 a.m. every day; specifically, take 1 L of the prepared first nutrient solution, dilute it 5 times with the sterile seawater, and evenly sprinkle it on the nursery pond; change the water in the nursery pond at 20:00 p.m. every day, and the amount of water changed is 1 / 2 of the water body; during this period, clean up the growing algae such as Enteromorpha in time.

[0077] (2) Days 7 to 14: Apply the first nutrient solution once at 8:00 a.m. and 14:00 p.m. every day; dilute 2 L of the prepared first nutrient solution 5 times with sterile seawater and evenly sprinkle it in the nursery pond; change the water in the nursery pond at 21:00 p.m. every day, with the amount of water changed being 1 / 2 of the water body.

[0078] (3) Days 14 to 24: Apply the first nutrient solution once at 8:00 a.m., 12:00 p.m., and 16:00 p.m. every day; Take 2 L of the prepared first nutrient solution, dilute it 5 times with the sterile seawater, and evenly sprinkle it in the nursery pond; Change the water in the nursery pond at 22:00 every night, and the amount of water changed is 1 / 2 of the water body.

[0079] (4) The cultivation in the nursery pond is terminated. The average length of the Sargassum mossoni seedlings after the cultivation in the nursery pond is 3.6 cm.

[0080] Step S2: Cultivation in low-velocity sea area: Select the Sargassum wei's seedlings with a length of more than 3 cm from the nursery pond and transfer them to a low-velocity sea area in Liusha Bay, Leizhou City, and cultivate them by longline cultivation for 33 days. The average water velocity in the low-velocity sea area is 1.6 m / s, the average water depth is 4 m, and the water transparency is 2 m. The second nutrient solution containing the second nutrient component is regularly applied to the low-velocity sea area for sea area cultivation. The application method is the same as step S2 in Example 1. During the period, the attached Enteromorpha, Ulva, silt, etc. are cleaned up in time. The average length of the Sargassum wei's seedlings after the low-velocity sea area cultivation is more than 5.4 cm.

[0081] Step S3: Cultivation in high-velocity sea area: The Sargassum sargassum seedlings with a length of more than 5 cm are selected from the low-velocity sea area and transferred to a high-velocity sea area in Caotan Town, Suixi County, Zhanjiang City, and cultivated for 38 days by longline cultivation. The water velocity in the high-velocity sea area is 3.2 m / s, the average water depth is 8 m, and the water transparency is 3 m; the third nutrient solution containing the third nutrient component is regularly applied to the high-velocity sea area for sea area cultivation, and the specific application method is the same as step S3 described in Example 1. During the period, the attached Enteromorpha, Ulva, silt, etc. are cleaned up in time. At this time, the average length of the Sargassum sargassum seedlings that have finished the high-velocity sea area cultivation is more than 12.1 cm, the body is strong, the rhizoid fixation is strong, and the stress resistance is good, and it can be transferred to the traditional cultivation sea area for cultivation.

[0082] Example 3

[0083] The configuration method of the first nutrient solution, the second nutrient solution, and the third nutrient solution of this embodiment is the same as that of Embodiment 1.

[0084] The type of Sargassum in this embodiment is the same as that in Example 1. The fertilization method for growing Sargassum seedlings in this embodiment is different from that in Example 1 in that it does not include a high-velocity sea area cultivation stage.

[0085] A fertilization method for promoting the growth of Sargassum seedlings in this embodiment includes the following steps:

[0086] Step S1 is the same as in Example 1;

[0087] Step S2 is the same as in Example 1;

[0088] Step S3: Secondary cultivation in low-velocity sea area: The third nutrient solution containing the third nutrient component is regularly applied to the low-velocity sea area in step S2 for sea area cultivation for 38 days, and the application method is the same as step S3 in Example 1; during the period, the attached Enteromorpha, Ulva, silt, etc. are cleaned in time. The average length of the Sargassum wei's seedlings after the secondary cultivation in the low-velocity sea area exceeds 10.1 cm, and the body is strong, and can be transferred to the traditional cultivation sea area for cultivation.

[0089] Example 4

[0090] The configuration method of the first nutrient solution and the second nutrient solution in this embodiment is the same as that in Embodiment 1.

[0091] The type of Sargassum in this embodiment is the same as that in Embodiment 1. The fertilization method for growing Sargassum seedlings in this embodiment is different from that in Embodiment 1 in that: Step 3 does not apply the third nutrient solution to the high flow rate sea area.

[0092] A fertilization method for promoting the growth of Sargassum seedlings in this embodiment includes the following steps:

[0093] Step S1 is the same as in Example 1;

[0094] Step S2 is the same as in Example 1;

[0095] Step S3: Cultivation in high-velocity sea area: Select the Sargassum wei's seedlings with a length of more than 5 cm from the low-velocity sea area and transfer them to the high-velocity sea area similar to Example 1 for cultivation by longline cultivation for 40 days; regularly apply the second nutrient solution containing the second nutrient component to the high-velocity sea area for sea area cultivation, and the application method is the same as step S3 in Example 1; during the period, the attached Enteromorpha, Ulva, silt, etc. are cleaned up in time. The average length of the Sargassum wei's seedlings after the high-velocity sea area cultivation is more than 10.6 cm, the body is strong, the rhizoid fixation is strong, and the stress resistance is good, and it can be transferred to the traditional cultivation sea area for cultivation.

[0096] Comparative Example 1

[0097] The existing method for cultivating Sargassum seedlings mainly comprises the following steps:

[0098] Step S1: collecting algae;

[0099] Step S2: allowing the Sargassum seedlings to be fixed to the seedling curtain and cultured in the nursery pond for 1-1.5 months;

[0100] Step S3: transferring the Sargassum seedlings from step S2 to sea for cultivation.

[0101] The bottleneck of the existing Sargassum seedling cultivation method is that the survival rate of Sargassum seedlings is low, and the seedlings almost stop growing after growing to 2 cm in the nursery pond for 1-1.5 months. Generally, they are transferred to the sea for cultivation after being cultivated to 5 cm. However, the cost of pond cultivation is relatively high at this time. In addition, due to the static water cultivation in the pond, the Sargassum seedlings that have finished the nursery pond cultivation have poor root fixation. Most of them will die under the scouring of wind and waves when directly transferred to the sea. Therefore, the seedling detachment rate and mortality rate are high, which often leads to seedling failure.

[0102] The cultivation effects of the fertilization methods for the growth of Sargassum seedlings in Examples 1 to 4 and Comparative Example 1 are shown in Table 4 below (the average length of the Sargassum seedlings exceeding 10 cm is considered to be the end of the dormancy period):

[0103] Table 4

[0104]

[0105] The fertilization method for growing Sargassum seedlings in Example 1 can make the average length of Sargassum wei's seedlings reach 11.3 cm in only 89 days, shortening the dormancy period to within 3 months; the cultivation rate is as high as 67.7%, significantly reducing the risk of high seedling shedding rate and high mortality rate during the dormancy period.

[0106] The fertilization method for growing Sargassum seedlings of Example 2 can make the average length of Sargassum mossoni seedlings reach 12.1 cm in only 95 days, shortening the dormancy period to about 3 months; the cultivation rate is as high as 65.1%, significantly reducing the risk of high seedling drop rate and high mortality rate during Sargassum mossoni seedling cultivation.

[0107] The fertilization method for growing Sargassum seedlings in Example 3 can make the average length of the Sargassum seedlings reach 10.6 cm in only 95 days, shortening the dormancy period to about 3 months; the cultivation rate is as high as 39.2%; the Sargassum seedlings cultivated in this example are not further intensively cultivated in high-velocity sea areas, so the Sargassum seedlings in this example are not as strong as the seedlings of the same period in Example 1, especially the average length is small, the adhesivity of the rhizoids is insufficient, so the seedling shedding rate on the seedling rope / seedling curtain and the culture rope is higher than that in Example 1, and the final cultivation rate is also lower than that in Example 1. However, compared with the existing fertilization method for growing Sargassum seedlings, this example still has significant improvements in shortening the dormancy period of seedlings and improving the cultivation rate.

[0108] The fertilization method for growing Sargassum seedlings in Example 4 can make the average length of Sargassum wei's seedlings reach 10.1 cm in only 97 days, shortening the dormancy period to about 3 months; the cultivation rate is as high as 52.1%; the Sargassum wei's seedlings cultivated in this example show a certain lack of fertility in the later stage, especially the vitamins and some plant growth hormones (gibberellins, brassinolide) in the second nutrient solution have limited effects on the growth promotion of seedlings, and more of the basic nutrition is insufficient. Therefore, the Sargassum wei's seedlings cultivated in this example are not as long as the average length of the seedlings of the same period in Example 1, the dormancy period is longer, and the cultivation rate is slightly lower. However, compared with the existing fertilization method for growing Sargassum seedlings, this example still has significant improvements in shortening the dormancy period of seedlings and increasing the cultivation rate.

[0109] Compared with the prior art, the fertilization method for promoting the growth of Sargassum seedlings of the present invention is based on the principle of culturing in three stages: culturing in a nursery pond, culturing in a low-velocity sea area, and culturing in a high-velocity sea area / secondary culturing in a low-velocity sea area, and adjusting and utilizing appropriate nutritional stimulation of substances such as plant growth hormones, so as to prompt the seedlings to break the summer dormancy period, accelerate growth, and enhance stress resistance, thereby achieving the purpose of improving the survival rate. The fertilization method for promoting the growth of Sargassum seedlings of the present invention can shorten the dormancy period of Sargassum seedlings to about 3 months, improve the cultivation rate of seedlings, and obtain high-quality seedlings with strong physique, strong rhizoid fixation ability, and strong stress resistance, greatly reducing the mortality rate and high seedling drop rate of seedlings caused by weak physique during the long dormancy period. The final cultivation rate is high, effectively solving the problems of high seedling drop rate and high mortality rate encountered in the existing Sargassum seedling cultivation technology, and has broad application prospects.

[0110] The above-mentioned embodiments only express several implementation methods of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, and the present invention is also intended to include these modifications and modifications.

Claims

1. A fertilization method for promoting the growth of Sargassum seedlings, characterized in that: The following steps are involved: Step S1: Cultivation in a nursery pond: placing Sargassum seedlings that are about to enter a dormant period in a nursery pond for shading and aeration cultivation, and periodically applying a first nutrient solution containing a first nutrient component to the nursery pond and gradually increasing the frequency of application; the first nutrient component includes 0.21-0.5 g / L basic nutrients, 8.5-22 mg / L trace elements, 0.68-1.75 mg / L vitamins, and 0.10-0.24 mg / L plant growth hormones; Step S2: Cultivation in low-velocity sea area: selecting the Sargassum seedlings with a length of more than 3 cm from the nursery pond, transferring them to a low-velocity sea area for cultivation, and regularly applying a second nutrient solution containing a second nutrient component to the low-velocity sea area for sea area cultivation; the second nutrient component includes 0.35-0.83 g / L basic nutrients, 10-46 mg / L trace elements, 0.8-2.8 mg / L vitamins and 0.0125-0.0233 mg / L plant growth hormones; Step S3: Cultivation in a high-velocity sea area: selecting the Sargassum seedlings with a length exceeding 5 cm from the low-velocity sea area and transferring them to a high-velocity sea area for cultivation until the average length of the Sargassum seedlings exceeds 10 cm, during which a third nutrient solution containing a third nutrient component is regularly applied to the high-velocity sea area for sea area cultivation; the third nutrient component includes basic nutrients, trace elements and plant growth hormones; or the second nutrient solution containing the second nutrient component is regularly applied to the high-velocity sea area for sea area cultivation; Or step S3: secondary cultivation in a low-flow sea area: regularly applying the third nutrient solution containing the third nutrient component to the low-flow sea area in step S2 for sea area cultivation until the average length of the Sargassum seedlings exceeds 10 cm; The third nutrient component consists of 0.63-1.13 g / L basic nutrients, 33.13-74.33 mg / L trace elements and 0.0063-0.0133 mg / L plant growth hormone.

2. The fertilization method for promoting the growth of Sargassum seedlings according to claim 1, characterized in that: The plant growth hormone in the first nutrient component includes 0.01-0.02 mg / L6-BA cytokinin, 0.01-0.02 mg / LGA3 gibberellin and 0.1-0.2 mg / L brassinolide; the plant growth hormone in the second nutrient component includes 0.0063-0.01 mg / L6-BA cytokinin and 0.0063-0.013 mg / LGA3 gibberellin; the plant growth hormone in the third nutrient component is 0.0063-0.0133 mg / L6-BA cytokinin.

3. The fertilization method for promoting the growth of Sargassum seedlings according to claim 1, characterized in that: The basic nutrients include KNO3, KH2PO4, MgSO4·7H2O, and NaNO3; the trace elements include FeSO4·7H2O, ZnSO4·7H2O, CuSO4·5H2O, MnSO4·7H2O, H3BO3, and Na2MoO4·10H2O; and the vitamins include vitamin B1, vitamin B12, vitamin C, and vitamin E.

4. The fertilization method for promoting the growth of Sargassum seedlings according to claim 1, characterized in that: The first nutrient solution is prepared by adding the first nutrient component to sterile seawater and fully dissolving it, and then refrigerating it for storage; the second nutrient solution is prepared by adding the second nutrient component to the precipitated and filtered seawater and fully dissolving it; the third nutrient solution is prepared by adding the third nutrient component to the precipitated and filtered seawater and fully dissolving it.

5. The fertilization method for promoting the growth of Sargassum seedlings according to claim 1, characterized in that: The specific method of gradually increasing the application frequency in the seedling cultivation pool in step S1 is: (1) Phase 1: Apply the first nutrient solution once a day; (2) Second stage: applying the first nutrient solution twice a day; the interval between the two applications is 5 to 6 hours; (3) The third stage: applying the first nutrient solution three times a day; the interval between each application is 3.5 to 4 hours; The first stage, the second stage and the third stage are divided by time according to the growth status of the Sargassum seedlings and other algae in the nursery pond.

6. The fertilization method for promoting the growth of Sargassum seedlings according to claim 1, characterized in that: The low-flow sea area culture in step S2 and the high-flow sea area culture in step S3 are both cultured using the longline cultivation method.

7. The fertilization method for promoting the growth of Sargassum seedlings according to claim 6, characterized in that: The method for applying the second / third nutrient solution is specifically as follows: prepare a number of small bottles, each of which is provided with a number of small holes; quickly dispense the second / third nutrient solution into the small bottles and seal them; weight the small bottles with heavy objects, and then hang the bottles under the seedling rope or seedling curtain or breeding cable at even intervals; and regularly replace the second / third nutrient solution in the small bottles.

8. The fertilization method for promoting the growth of Sargassum seedlings according to claim 1, characterized in that: The nursery pond should be covered with a sunshade net to keep the light intensity no more than 20,000 lx; ​​the aeration volume should be kept no less than 10 L / min / m 3 Aeration culture.

9. The fertilization method for promoting the growth of Sargassum seedlings according to claim 1, characterized in that: The low-flow sea area is a sea area with smooth water exchange, an average water flow velocity not exceeding 3m / s, a water depth not exceeding 10m, a water transparency not less than 1m, and excellent water quality.

10. The fertilization method for promoting the growth of Sargassum seedlings according to claim 1, characterized in that: The high-flow sea area is a sea area with smooth water exchange, an average water flow velocity of 3 to 5 m / s, a water depth not exceeding 10 m, a water transparency of not less than 1 m, and excellent water quality.

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