A method of fertilization for promoting the growth of sargassum seedlings

Abstract

The present application relates to a kind of fertilization methods for promoting growth of sargassum thalli, comprising the following steps: step S1: the sargassum thalli to be in dormancy period is set in the seedling pond, light is shielded, aeration culture, first nutrient solution is applied to the seedling pond and gradually improves application frequency;Step S2: select qualified sargassum thalli and transfer to low flow rate sea area culture, regularly apply second nutrient solution;Step S3: select qualified sargassum thalli and transfer to high flow rate sea area culture until the average length of the sargassum thalli exceeds 10cm, apply third nutrient solution or second nutrient solution culture;Or step S3: apply third nutrient solution to low flow rate sea area in step S2 culture until the average length of the sargassum thalli exceeds 10cm.The present application relates to a kind of fertilization methods for promoting growth of sargassum thalli, which can effectively improve the growth rate and stress resistance of seedlings, shorten the dormancy period and improve the survival rate of seedlings.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of seaweed cultivation, in particular to a fertilization method for promoting the growth of Sargassum natans seedlings. BACKGROUND

[0002] Sargassum, classified as Phaeophyta, Fucales, Sargassaceae and Sargassum, is a large alga with important economic value, which not only plays an important role in the ecosystem, but also has a wide range of applications in industry, agriculture, food, medicine and other fields. Under the dual influence of global climate change and overfishing, the nearshore Sargassum bed tends to be degraded and shrinks, and the Sargassum resource is facing threats. Artificial large-scale cultivation through sexual reproduction has become an effective way to meet the demand for Sargassum resources and protect ecological resources.

[0003] The breeding season of Sargassum usually occurs in the high-temperature period of summer. The seedlings of Sargassum grow to 2cm after 1-1.5 months, and the growth and development speed of the seedlings at this stage is normal, without the need for excessive human intervention. However, after growing to 2cm, the seedlings of Sargassum enter a long slow growth stage (commonly known as the dormancy period), and generally need to go through a 5-7 month dormancy period before growing to more than 5cm, at which time the growth speed will return to normal. During the slow growth stage, especially in early summer, the growth speed of Sargassum will slow down, and then it may enter a dormant state until the environmental conditions improve, such as a decrease in temperature, at which time it will resume growth; for example, the dormancy period of Sargassum thunbergii can last for 6 months, from May to November.

[0004] In addition, due to the long duration of the dormancy period, the seedlings in the dormancy period are weak and small in size, and have poor stress resistance, resulting in a low survival rate of the seedlings. For example, the seedlings covered with mud and sand cannot perform photosynthesis and die, and for example, the seedlings have insufficient anchoring force of the rhizoids and are easily detached from the seedling ropes / seedling curtains during cultivation by the extended rope method on the sea (the seedlings have not yet developed air bladders and cannot float, so the detached seedlings generally sink to the bottom of the water and cannot perform photosynthesis and die). Therefore, the long duration of the dormancy period and the low survival rate of the seedlings are a technical bottleneck for current large-scale artificial cultivation. SUMMARY

[0005] Therefore, the purpose of the present application is to provide a fertilization method for promoting the growth of Sargassum natans seedlings, which can effectively improve the growth speed and stress resistance of the seedlings, shorten the dormancy period and improve the survival rate of the seedlings.

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

[0007] Step S1: seedling pond culture: Sargassum thunbergii seedlings about to enter the dormancy period are set in a seedling pond for light-shielded and aeration culture, during which a first nutrient solution containing first nutrient components is applied to the seedling pond at a gradually increased frequency; the first nutrient components include 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 regulators;

[0008] Step S2: low-flow sea area culture: S. thunbergii seedlings with a length of more than 3 cm are selected from the seedling pond and transferred to a low-flow sea area for culture, during which a second nutrient solution containing second nutrient components is applied to the low-flow sea area for sea area culture; the second nutrient components include 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 regulators;

[0009] Step S3: high-flow sea area culture: S. thunbergii seedlings with a length of more than 5 cm are selected from the low-flow sea area and transferred to a high-flow sea area for culture until the average length of the S. thunbergii seedlings is more than 10 cm, during which a third nutrient solution containing third nutrient components is applied to the high-flow sea area for sea area culture; the third nutrient components include basic nutrients, trace elements and plant growth regulators; or the second nutrient solution containing the second nutrient components is applied to the high-flow sea area for sea area culture;

[0010] or Step S3: secondary low-flow sea area culture: the third nutrient solution containing the third nutrient components is applied to the low-flow sea area in Step S2 for sea area culture until the average length of the S. thunbergii seedlings is more than 10 cm; the third nutrient components consist 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 regulators.

[0011] The present application is a method for promoting the growth of Sargassum thunbergii. The present application is based on the fact that Sargassum thunbergii is a wave-loving plant. In areas with strong wind and waves, the exchange of air and water is usually more frequent, and Sargassum thunbergii grows better. Based on this characteristic of Sargassum thunbergii, the present application divides the cultivation of Sargassum thunbergii seedlings into three stages. The first stage is cultivation in a nursery pond, the second stage is cultivation in an area with low flow rate, and the third stage is cultivation in an area with high flow rate or secondary cultivation in an area with low flow rate. The Sargassum thunbergii seedlings in the first stage are weak and small in size and need to be intensively cultivated in the pond to break their dormancy and make them stronger and increase the anchoring force of their rhizoids. Although the Sargassum thunbergii seedlings in the first stage have undergone some intensive cultivation, their anchoring strength and stress resistance are still not enough to be directly cultivated in an area with high flow rate, so they need to be further intensively cultivated in an area with low flow rate to further strengthen their stress resistance and rhizoid anchoring force. The Sargassum thunbergii seedlings in the third stage, which have undergone further intensive cultivation, can be transferred to an area with high flow rate for further strengthening of their stress resistance and better growth, or they can be further cultivated in an area with low flow rate in the second stage until their average length exceeds 10 cm, considering the economic cost, to avoid cultivation in an area with high flow rate, where the flow rate is higher and the exchange of water is faster, and the concentration of nutrients needs to be further increased to ensure the fertility of the Sargassum thunbergii seedlings. The present application is a method for promoting the growth of Sargassum thunbergii seedlings. During the cultivation of Sargassum thunbergii seedlings in the dormancy period, the present application applies an appropriate amount of nutrients containing plant hormones to break the dormancy of the Sargassum thunbergii seedlings, accelerate their growth, shorten the dormancy period, make them stronger and more robust, and increase their rhizoid anchoring ability, thereby effectively improving their stress resistance and survival rate, which is of great significance for the large-scale artificial cultivation of Sargassum thunbergii.

[0012] Further, the plant growth hormone in the first nutrient component includes 0.01-0.02 mg / L 6-BA cell division factor, 0.01-0.02 mg / L GA3 gibberellin and 0.1-0.2 mg / L brassinolide; the plant growth hormone in the second nutrient component includes 0.0063-0.01 mg / L 6-BA cell division factor and 0.0063-0.013 mg / L GA3 gibberellin; and the plant growth hormone in the third nutrient component is 0.0063-0.0133 mg / L 6-BA cell division factor. The inventor has found that the Sargassum thunbergii seedlings in the culture stage of the seedling tank have entered the dormancy period and need the three kinds of plant growth hormones to achieve a better growth promoting effect. The main function of the gibberellin is to break the dormancy state, and the main functions of the cell division factor and the brassinolide are to promote the growth of the seedlings. The three kinds of plant growth hormones have the best effect. The Sargassum thunbergii seedlings cultured in the low flow area have a length of more than 3 cm. The seedlings in this stage are not sensitive to the stimulation of the brassinolide, and a high concentration of the brassinolide will inhibit the growth of the Sargassum thunbergii. Therefore, the second nutrient component does not contain the brassinolide for environmental protection and economic considerations. The Sargassum thunbergii seedlings cultured in the low flow area have basically broken the dormancy state. The anchoring strength of the rhizoids and the stress resistance of the seedlings are improved, and the survival rate is also significantly increased. The gibberellin has a limited effect on promoting the growth of the Sargassum thunbergii, and only the cell division factor can effectively promote the growth of the seedlings. Therefore, the third nutrient component contains only the cell division factor for environmental protection and economic considerations. The above-mentioned component and concentration range of the plant growth hormone are most beneficial to the growth of the Sargassum thunbergii seedlings.

[0013] Further, the basic nutrient substance includes 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] Further, the configuration method of the first nutrient solution is to add the first nutrient component to the sterile seawater, dissolve it thoroughly and then store it in the refrigerator; the configuration method of the second nutrient solution is to add the second nutrient component to the seawater after precipitation and filtration and dissolve it thoroughly; and the configuration method of the third nutrient solution is to add the third nutrient component to the seawater after precipitation and filtration and dissolve it thoroughly.

[0015] Further, the specific method for gradually increasing the application frequency in the step S1 is as follows:

[0016] (1) The first stage: the first nutrient solution is applied once a day;

[0017] (2) the second stage: the first nutrient solution is applied twice a day; the time interval between the two applications is 5-6 hours;

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

[0019] The first stage, the second stage, and the third stage are divided by time, and the duration is adjusted according to the growth state of the S. thunbergii seedlings and the weeds in the seedling pond.

[0020] In the step S1 seedling pond culture stage, since the seedling pond is a closed breeding space, the utilization of nutrients is more sufficient and effective than in sea area breeding. If the initial fertilization concentration is too high, or the fertilization amount is too large, weeds such as Enteromorpha, Ulva, and Gelidiaceae are likely to breed, and the weeds have strong vitality and can quickly occupy the growth space and nutrients of S. thunbergii, leading to seedling failure. Therefore, in order to strictly prevent the breeding and excessive growth of weeds such as Enteromorpha, Ulva, and Gelidiaceae, the seedling pond culture stage needs to gradually increase the application frequency of the first nutrient solution in stages.

[0021] Further, the low-flow sea area culture of step S2 and the high-flow sea area culture of step S3 are both cultured by the long-line cultivation method.

[0022] Further, the application method of the second nutrient solution is as follows: a plurality of small bottles are prepared, and a plurality of small holes are provided on the small bottles; the second nutrient solution is quickly divided and packaged into the small bottles and covered; the small bottles are counterweighted with weights, and then hung evenly on the seedling ropes / seedling curtains or breeding cables at intervals; and the second nutrient solution in the small bottles is replaced regularly.

[0023] Further, the application method of the third nutrient solution is as follows: a plurality of small bottles are prepared, and a plurality of small holes are provided on the small bottles; the third nutrient solution is quickly divided and packaged into the small bottles and covered; the small bottles are counterweighted with weights, and then hung evenly on the seedling ropes / seedling curtains or breeding cables at intervals; and the third nutrient solution in the small bottles is replaced regularly.

[0024] Further, the seedling pond needs to be covered with a sunshade net to keep the light intensity not more than 20000lx; and the aeration amount is kept not less than 10L / min / m 3 Aeration culture. Ensure water exchange and water flow in the breeding pond to control the breeding and excessive growth of weeds such as Enteromorpha.

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

[0026] Further, the high flow velocity sea area is a sea area with fluent water exchange, an average water flow velocity of 3-5 m / s, a water depth of no more than 10 m, a water quality transparency of no less than 1 m, and excellent water quality.

[0027] For better understanding and implementation, the application will be described in detail below in conjunction with the embodiments. DETAILED DESCRIPTION

[0028] It should be clear that the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

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

[0030] In the description of the present application, it should be understood that the terms "first", "second", "third" and the like are only used to distinguish similar objects, and do not necessarily describe a specific order or sequence, nor can they be understood as indicating or implying relative importance. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0031] In addition, in the description of the present application, "multiple" means two or more, unless otherwise specified. "And / or" describes the association between the associated objects, which means that there can be three relationships, for example, A and / or B can mean that A exists alone, A and B exist together, and B exists alone. The character " / " generally represents that the associated objects before and after are in an "or" relationship.

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

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

[0034] Further, the first nutrient ingredients and the content of each ingredient in the first nutrient solution are shown in Table 1; the content of the first nutrient ingredients in the first nutrient solution in Table 1 is suitable for a seedling pool with a width of 3 m, a length of 6 m, and a culture water depth of 0.6 m; and the configuration method of the first nutrient solution is as follows: the first nutrient ingredients in Table 1 are added to 10-12 L of sterile seawater, and after being fully dissolved, the solution is stored at 2-8 DEG C.

[0035] Further, in order to ensure the water gas exchange and flowability of the water body of the seedling pool, the seedling pool needs to be aerated, and the aeration amount is not less than 10 L / min / m 3 .

[0036] Further, in order to control the breeding and excessive growth of Enteromorpha and other algae, the seedling pool needs to be covered with a shading net to keep the light intensity not more than 20000 lx.

[0037] Further, the step S1 of the fertilization method for promoting the growth of S. thunbergii seedlings further controls the breeding and excessive growth of Enteromorpha and other algae by gradually increasing the application frequency of the first nutrient solution, water replacement, and algae cleaning in stages, and the specific process is as follows:

[0038] (1) First stage: the first nutrient solution is applied once a day in the morning; specifically, 1-2 L of the prepared first nutrient solution is diluted 4-5 times with sterile seawater, and is uniformly sprayed on the seedling pool; 10-12 hours after application, the seedling pool is replaced with water, and the water replacement amount per day is 1 / 2 of the water body; and Enteromorpha and other algae breeding during cultivation is cleaned in time.

[0039] (2) Second stage: the first nutrient solution is applied once in the morning and once in the afternoon each day, and the time interval between the two applications is 5-6 hours; specifically, 1-2 L of the prepared first nutrient solution is diluted 4-5 times with sterile seawater, and is uniformly sprayed on the seedling pool; 6-8 hours after the second application, the seedling pool is replaced with water, and the water replacement amount per day is 1 / 2 of the water body.

[0040] (3) Third stage: the first nutrient solution is applied once in the morning, once at noon, and once in the afternoon each day, and the time interval between each application is 3.5-4 hours; 1-2 L of the prepared first nutrient solution is diluted 4-5 times with sterile seawater, and is uniformly sprayed on the seedling pool; 5-6 hours after the third application, the seedling pool is replaced with water, and the water replacement amount per day is 1 / 2 of the water body.

[0041] (4) When the average length of the S. thunbergii seedlings exceeds 3 cm, the culture in the seedling pool is ended.

[0042] Further, the first stage, the second stage and the third stage are divided by time, and the time length is adjusted according to the growth state of the Sargassum thunbergii seedlings and the weed algae in the seedling culture pond.

[0043] Table 1

[0044]

[0045] Step S2: low-flow sea area culture: the Sargassum thunbergii seedlings with a length of more than 3 cm are selected from the seedling culture pond and transferred to a low-flow sea area for 30-40 days of culture by using the long-line cultivation method, and during the culture, a second nutrient solution containing a second nutrient component is regularly applied to the low-flow sea area for sea area culture.

[0046] Further, the low-flow sea area is a sea area with unobstructed water flow exchange, an average water flow speed of not more than 3 m / s, a water depth of not more than 10 m, a water quality transparency of not less than 1 m, and excellent water quality.

[0047] Further, the second nutrient component and the content of each component in the second nutrient solution are shown in Table 2; and the configuration method of the second nutrient solution is that the second nutrient component in Table 2 is added to 30-32 L of precipitated and filtered seawater for sufficient dissolution.

[0048] Further, the application method of the second nutrient solution is as follows: a plurality of plastic vials with a capacity of more than 600 ml are prepared, and 80-100 small holes are punctured on the plastic vials with a small needle; the second nutrient solution is quickly divided and packaged into the plastic vials and capped, and each plastic vial contains 500-600 ml of the second nutrient solution; the plastic vials are counterweighted with small stones or other weights, and then hung at intervals uniformly at a position of 15-20 cm below the seedling rope / seedling curtain or the culture cable; the second nutrient solution in the plastic vials is replaced once every 6-7 days. The culture is ended when the average length of the Sargassum thunbergii seedlings exceeds 5 cm.

[0049] Table 2

[0050]

[0051] Step S3: high-flow sea area culture: the Sargassum thunbergii seedlings with a length of more than 5 cm are selected from the low-flow sea area and transferred to a high-flow sea area for culture by using the long-line cultivation method until the average length of the Sargassum thunbergii seedlings exceeds 10 cm, and the high-flow sea area culture is ended, during which a third nutrient solution containing a third nutrient component is regularly applied to the high-flow sea area for sea area culture, or during which the second nutrient solution containing the second nutrient component is regularly applied to the high-flow sea area according to the application method of the second nutrient solution.

[0052] Further, the high flow velocity sea area is a sea area with fluent flow exchange, average flow velocity of no more than 3-5 m / s, water depth of no more than 10 m, water quality transparency of no less than 1 m, and excellent water quality.

[0053] Further, the third nutrient component and the content of each component in the third nutrient solution are shown in Table 3; and the preparation method of the third nutrient solution is as follows: the third nutrient component in Table 3 is added into 30-32 L of the precipitated and filtered seawater and dissolved thoroughly.

[0054] Further, the application method of the third nutrient solution is as follows: a plurality of plastic vials with a capacity of more than 600 ml are prepared, and 80-100 small holes are punched on the plastic vials with a small needle; the second nutrient solution is quickly divided and packaged into the plastic vials and capped, each of the plastic vials containing 500-600 ml of the second nutrient solution; the plastic vials are counterweighted with small stones or other weights, and then hung at intervals uniformly at a position of 15-20 cm below the seed rope / seed curtain or the culture cable; the second nutrient solution in the plastic vials is replaced once every 6-7 days.

[0055] Table 3

[0056]

[0057] Or step S3: secondary culture in the low flow velocity sea area: the third nutrient solution containing the third nutrient component is applied to the low flow velocity sea area in step S2 according to the application method of the third nutrient solution to culture the sea area until the average length of the sargassum foenum-graceum seedlings exceeds 10 cm.

[0058] Example 1

[0059] The preparation method of the first nutrient solution in the embodiment is as follows: the first nutrient component in Table 1 is added into 10 L of sterile seawater and dissolved thoroughly, and then stored at 2-8 ℃.

[0060] The preparation method of the second nutrient solution in the embodiment is as follows: the second nutrient component in Table 2 is added into 30 L of precipitated and filtered seawater and dissolved thoroughly.

[0061] The preparation method of the third nutrient solution in the embodiment is as follows: the third nutrient component in Table 3 is added into 30 L of precipitated and filtered seawater and dissolved thoroughly.

[0062] The sargassum foenum-graceum in the embodiment is S. wrightii, the breeding pond is a cement pond with a size of 3×6×1.5 m, and the culture water depth is 0.6 m; the fertilization method for promoting the growth of sargassum foenum-graceum seedlings in the embodiment comprises the following steps:

[0063] Step S1: culture in a seedling pool: select 1-month-old S. wrightii seedlings and place them in the seedling pool for light-shielded and aeration culture for 24 days, with a water depth of 60 cm and an aeration rate of 20 L / min / m 3 Meanwhile, cover the seedling pool with a sunshade net so that the internal light intensity does not exceed 20,000 lx; periodically apply the first nutrient solution containing the first nutrient component to the seedling pool, and gradually increase the application frequency of the first nutrient solution in stages, change the water, and clean the algae, with the specific process being as follows:

[0064] (1) Days 1-7: apply the first nutrient solution once a day at 8:00 in the morning; specifically, take 1.5 L of the prepared first nutrient solution, dilute it 5 times with sterile seawater, and uniformly sprinkle it on the seedling pool; change the water in the seedling pool at 20:00 in the evening every day, with the amount of water changed being 1 / 2 of the water body; and clean the growing Enteromorpha and other algae in a timely manner.

[0065] (2) Days 7-14: apply the first nutrient solution once a day at 8:00 in the morning and at 14:00 in the afternoon; take 1.5 L of the prepared first nutrient solution, dilute it 5 times with sterile seawater, and uniformly sprinkle it on the seedling pool; change the water in the seedling pool at 21:00 in the evening every day, with the amount of water changed being 1 / 2 of the water body.

[0066] (3) Days 14-24: apply the first nutrient solution once a day at 8:00 in the morning, at 12:00 in the noon, and at 16:00 in the afternoon; take 1.5 L of the prepared first nutrient solution, dilute it 5 times with the sterile seawater, and uniformly sprinkle it on the seedling pool; change the water in the seedling pool at 21:00 in the evening every day, with the amount of water changed being 1 / 2 of the water body.

[0067] (4) end the culture in the seedling pool. The average length of the S. wrightii seedlings after ending the culture in the seedling pool is 3.5 cm.

[0068] Step S2: low flow rate sea area culture: the Sargassum wightii seedlings with a length of more than 3 cm are selected from the rearing tank and transferred to a low flow rate sea area in Baisha Town, Xuwen County, Zhanjiang City, and cultured for 30 days by using the extended rope cultivation method, the average water flow rate of the low flow rate sea area is 2 m / s, the average water depth is 4 m, and the water transparency is 3 m; the second nutrient solution containing the second nutrient component is regularly applied to the low flow rate sea area for sea area culture, and the application method is as follows: 32 plastic vials with a capacity of more than 600 ml are prepared, and 80 small holes are punched on the plastic vials with a small needle; the second nutrient solution is quickly divided and packaged into the plastic vials and capped, and each plastic vial contains 500 ml of the second nutrient solution; the plastic vials are counterweighted with small stones and the like, and then uniformly spaced and tied to the lower part of 15 cm of the seedling rope / seedling curtain or the culture cable; the second nutrient solution in the plastic vials is replaced every 7 days; and the attached Enteromorpha, Ulva, silt and the like are cleaned in a timely manner. The average length of the Sargassum wightii seedlings after the low flow rate sea area culture is more than 5.2 cm.

[0069] Step S3: high flow rate sea area culture: the Sargassum wightii seedlings with a length of more than 5 cm are selected from the low flow rate sea area and transferred to a high flow rate sea area in Baisha Town, Xuwen County, Zhanjiang City, and cultured for 35 days by using the extended rope cultivation method, the water flow rate of the high flow rate sea area is 4.2 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 flow rate sea area for sea area culture, and the application method is as follows: 33 plastic vials with a capacity of more than 600 ml are prepared, and 80 small holes are punched on the plastic vials with a small needle; the third nutrient solution is quickly divided and packaged into the plastic vials and capped, and each plastic vial contains 500 ml of the third nutrient solution; the plastic vials are counterweighted with small stones and the like, and then uniformly spaced and tied to the lower part of 15 cm of the seedling rope / seedling curtain or the culture cable; the third nutrient solution in the plastic vials is replaced every 7 days. The attached Enteromorpha, Ulva, silt and the like are cleaned in a timely manner. The average length of the Sargassum wightii seedlings after the high flow rate sea area culture is more than 11.3 cm, the body is robust, the anchoring force of the false root is strong, and the stress resistance is good, and the Sargassum wightii seedlings can be transferred to a traditional cultivation sea area for growing cultivation.

[0070] Example 2

[0071] The configuration method of the first nutrient solution of the embodiment is as follows: the first nutrient components in Table 1 are added to 11 L of sterile seawater, and after being fully dissolved, the solution is stored at 2-8 ℃.

[0072] The configuration method of the second nutrient solution of the embodiment is as follows: the second nutrient components in Table 2 are added to 30 L of seawater filtered by sedimentation, and the solution is fully dissolved.

[0073] The third nutrient solution in the embodiment is prepared by adding the third nutrient components in Table 3 into 30 L of the precipitated filtered seawater and dissolving thoroughly.

[0074] The Sargassum in the embodiment is S. mooreanum, and the seedling pond is a cement pond with a size of 3 x 6 x 1.2 m; the fertilization method for promoting the growth of Sargassum seedlings in the embodiment comprises the following steps:

[0075] Step S1: seedling pond culture: the 1.5-month-old S. mooreanum seedlings are selected and cultured in the seedling pond under shading and aeration for 24 days, the water depth is 60 cm, and the aeration amount is 28 L / min / m 3 Meanwhile, a shading net is covered on the seedling pond to make the internal light intensity not more than 20,000 lx; the first nutrient solution containing the first nutrient components is applied to the seedling pond at regular time intervals, and the application frequency of the first nutrient solution is gradually increased in stages, and the water is changed and the miscellaneous algae are cleaned up, and the specific process is as follows:

[0076] (1) 1-7 days: the first nutrient solution is applied once a day at 8:00 in the morning; specifically, 1 L of the prepared first nutrient solution is diluted 5 times with sterile seawater, and is uniformly sprayed on the seedling pond; the seedling pond is changed with water at 20:00 in the evening every day, and the water changing amount is 1 / 2 of the water body; the growing Enteromorpha and other miscellaneous algae are cleaned up in time.

[0077] (2) 7-14 days: the first nutrient solution is applied once a day at 8:00 in the morning and at 14:00 in the afternoon; 2 L of the prepared first nutrient solution is diluted 5 times with sterile seawater, and is uniformly sprayed on the seedling pond; the seedling pond is changed with water at 21:00 in the evening every day, and the water changing amount is 1 / 2 of the water body.

[0078] (3) 14-24 days: the first nutrient solution is applied once a day at 8:00 in the morning, at 12:00 in the noon and at 16:00 in the afternoon; 2 L of the prepared first nutrient solution is diluted 5 times with sterile seawater, and is uniformly sprayed on the seedling pond; the seedling pond is changed with water at 22:00 in the evening every day, and the water changing amount is 1 / 2 of the water body.

[0079] (4) the seedling pond culture is ended. The average length of the S. mooreanum seedlings after the seedling pond culture is ended is 3.6 cm.

[0080] Step S2: low-flow sea area cultivation: the Sargassum wrightii seedlings with a length of more than 3 cm are selected from the rearing tank and transferred to a low-flow sea area in Liusha Bay, Leizhou City, and cultivated by the long-line cultivation method for 33 days. The average water flow speed of the low-flow 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-flow sea area for sea area cultivation, and the application method is the same as that of step S2 of Example 1. The attached Enteromorpha, Ulva, silt, etc. are cleaned in time during the period. The average length of the Sargassum muticum seedlings after the low-flow sea area cultivation is more than 5.4 cm.

[0081] Step S3: high-flow sea area cultivation: the Sargassum muticum seedlings with a length of more than 5 cm are selected from the low-flow sea area and transferred to a high-flow sea area in Caotan Town, Suixi County, Zhanjiang City, and cultivated by the long-line cultivation method for 38 days. The water flow speed of the high-flow 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-flow sea area for sea area cultivation, and the application method is the same as that of step S3 of Example 1. The attached Enteromorpha, Ulva, silt, etc. are cleaned in time during the period. At this time, the average length of the Sargassum muticum seedlings after the high-flow sea area cultivation is more than 12.1 cm, the body is healthy, the anchoring force of the rhizoids is strong, and the stress resistance is good, which can be transferred to a traditional cultivation sea area for growing cultivation.

[0082] Example 3

[0083] The configuration methods of the first nutrient solution, the second nutrient solution, and the third nutrient solution of the present example are the same as those of Example 1.

[0084] The species of Sargassum of the present example are the same as those of Example 1. The fertilization method for the growth of Sargassum seedlings of the present example is different from that of Example 1 in that the high-flow sea area cultivation stage is not included.

[0085] The fertilization method for promoting the growth of Sargassum seedlings of the present example includes the following steps:

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

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

[0088] Step S3: low-flow sea area secondary cultivation: the third nutrient solution containing the third nutrient component is regularly applied to the low-flow sea area in step S2 for sea area cultivation for 38 days, and the application method is the same as that of step S3 of Example 1. The attached Enteromorpha, Ulva, silt, etc. are cleaned in time during the period. The average length of the Sargassum wrightii seedlings after the low-flow sea area secondary cultivation is more than 10.1 cm, the body is healthy, and it can be transferred to a traditional cultivation sea area for growing cultivation.

[0089] Example 4

[0090] The first nutrient solution and the second nutrient solution of the embodiment are configured in the same way as in Embodiment 1.

[0091] The species of the Sargassum of the embodiment is the same as in Embodiment 1. The fertilization method for the growth of the Sargassum seedlings of the embodiment is different from that of Embodiment 1 in that the step 3 does not apply the third nutrient solution to the high-flow sea area.

[0092] The fertilization method for promoting the growth of the Sargassum seedlings of the embodiment comprises the following steps:

[0093] The step S1 is the same as in Embodiment 1;

[0094] The step S2 is the same as in Embodiment 1;

[0095] Step S3: high-flow sea area cultivation: the S. wightii seedlings with a length of more than 5 cm are selected from the low-flow sea area and transferred to the high-flow sea area in the same way as in Embodiment 1 for cultivation by the long-line cultivation method for 40 days; the second nutrient solution containing the second nutrient component is applied to the high-flow sea area for sea area cultivation, and the application method is the same as that in the step S3 of Embodiment 1; the attached Enteromorpha, Ulva, silt and the like are cleaned in time during the period. The average length of the S. wightii seedlings after the high-flow sea area cultivation is more than 10.6 cm, the body is healthy, the anchoring force of the rhizoids is strong, and the stress resistance is good, which can be transferred to the traditional cultivation sea area for growing cultivation.

[0096] Comparative Example 1 Comparative Example 2

[0097] The existing cultivation method of the Sargassum seedlings mainly comprises the following steps:

[0098] Step S1: collecting seed algae;

[0099] Step S2: anchoring the Sargassum seedlings to the seedling screen in the seedling pond for cultivation for 1-1.5 months;

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

[0101] The bottleneck of the existing cultivation method of the Sargassum seedlings is that the survival rate of the Sargassum seedlings is low, and the seedlings grow to 2 cm after being cultivated in the seedling pond for 1-1.5 months, and then almost stop growing. Generally, the seedlings are transferred to the sea area for cultivation when they grow to 5 cm, but at this time, the cost of cultivation in the pond is relatively high, and because the seedlings are cultivated in the static water in the pond, the anchoring force of the rhizoids of the Sargassum seedlings after the cultivation in the seedling pond is poor, and most of the seedlings are washed away and die under the erosion of the wind and waves after being directly transferred to the sea area, so the seedling loss rate and the mortality rate are high, which often leads to the failure of seedling cultivation.

[0102] The cultivation effects of the fertilization methods for the growth of Sargassum thalli in Examples 1-4 and Comparative Example 1 are shown in Table 4 (the average length of Sargassum thalli over 10 cm is regarded as the end of the dormancy period):

[0103] Table 4

[0104]

[0105] The fertilization method for the growth of Sargassum thalli in Example 1 can make the average length of S. wulfianum thalli reach 11.3 cm in only 89 days, shorten the dormancy period to within 3 months, and the survival rate is as high as 67.7%, which significantly reduces the risk of high thallus shedding rate and high mortality rate during the dormancy period.

[0106] The fertilization method for the growth of Sargassum thalli in Example 2 can make the average length of S. muticum thalli reach 12.1 cm in only 95 days, shorten the dormancy period to about 3 months, and the survival rate is as high as 65.1%, which significantly reduces the risk of high thallus shedding rate and high mortality rate during the dormancy period.

[0107] The fertilization method for the growth of Sargassum thalli in Example 3 can make the average length of S. wulfianum thalli reach 10.6 cm in only 95 days, shorten the dormancy period to about 3 months, and the survival rate is as high as 39.2%. The S. wulfianum thalli cultivated in this example are not as robust as the thalli in Example 1, especially in terms of average length and the adhesion of the false roots, so the thallus shedding rate on the ropes / curtains and the cultivation ropes is higher than that in Example 1, and the final survival rate is also lower than that in Example 1. However, compared with the existing fertilization method for the growth of Sargassum thalli, this example still has significant improvements in shortening the dormancy period and improving the survival rate.

[0108] The fertilization method for the growth of Sargassum thalli in Example 4 can make the average length of S. wulfianum thalli reach 10.1 cm in only 97 days, shorten the dormancy period to about 3 months, and the survival rate is as high as 52.1%. The S. wulfianum thalli cultivated in this example show a certain lack of nutrients in the later period, especially the limited growth-promoting effect of vitamins and some plant hormones (gibberellins and brassinosteroids) in the second nutrient solution, and more basic nutrient deficiencies. Therefore, the S. wulfianum thalli cultivated in this example have a longer dormancy period and a lower survival rate than the thalli in Example 1. However, compared with the existing fertilization method for the growth of Sargassum thalli, this example still has significant improvements in shortening the dormancy period and improving the survival rate.

[0109] Compared with the prior art, the fertilization method for promoting the growth of Sargassum thalli of the present application has the principle of culture through three stages of seedling culture, low-flow sea area culture, high-flow sea area culture / low-flow sea area secondary culture, and adjusting and utilizing suitable nutrient stimulation of plant growth substances and other substances to promote the thalli to break the summer dormancy period, accelerate the growth, and enhance the stress resistance, so as to achieve the purpose of improving the survival rate. The fertilization method for promoting the growth of Sargassum thalli of the present application can shorten the dormancy period of Sargassum thalli to about 3 months, can improve the survival rate of the thalli, and the high-quality seedlings obtained are robust, have strong anchoring ability of false roots, and have strong stress resistance, greatly reducing the mortality and the high risk of seedling loss rate of the thalli caused by small size during the long dormancy period, and finally having high survival rate, effectively solving the problems of high seedling loss rate and high mortality encountered in the existing Sargassum seedling culture technology, and having a wide application prospect.

[0110] The above-described embodiments only express several embodiments of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the scope of the patent. It should be noted that for ordinary skilled persons in the art, several modifications and improvements can be made without departing from the concept of the present application, and the present application also intends to include these modifications and improvements.

Claims

1. A fertilization method for promoting the growth of Sargassum seedlings, characterized by: The following steps are involved: Step S1: Cultivating in a nursery pond: Sargassum seedlings about to enter a dormant period are placed in a nursery pond, shaded, and aerated for cultivation. During this period, a first nutrient solution containing a first nutrient component is regularly applied to the nursery pond, and the application frequency is gradually increased; the first nutrient component includes 0.21-0.5 g / L of basic nutrients, 8.5-22 mg / L of trace elements, 0.68-1.75 mg / L of vitamins, and 0.10-0.24 mg / L of plant growth hormones; the plant growth hormones in the first nutrient component include 0.01-0.02 mg / L of 6-BA cytokinin, 0.01-0.02 mg / L of GA3 gibberellin, and 0.1-0.2 mg / L of brassinolide; Step S2: Cultivating in a low-flow sea area: selecting the Sargassum seedlings longer than 3 cm from the nursery pond, transferring them to a low-flow sea area for cultivation, and regularly applying a second nutrient solution containing a second nutrient component to the low-flow sea area for sea area cultivation; the second nutrient component includes 0.35-0.83 g / L of basic nutrients, 10-46 mg / L of trace elements, 0.8-2.8 mg / L of vitamins, and 0.0125-0.0233 mg / L of plant growth hormones; the plant growth hormones in the second nutrient component include 0.0063-0.01 mg / L of 6-BA cytokinin and 0.0063-0.013 mg / L of GA3 gibberellin; Step S3: Cultivating in a high-flow sea area: selecting the Sargassum seedlings longer than 5 cm from the low-flow sea area, transferring them to a high-flow sea area, and culturing them until the average length of the Sargassum seedlings exceeds 10 cm. During this period, a third nutrient solution containing a third nutrient component is regularly added to the high-flow 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 added to the high-flow 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; the plant growth hormone in the third nutrient component is 0.0063-0.0133 mg / L 6-BA cytokinin; The average water flow velocity in the low-flow sea area does not exceed 3m / s; the average water flow velocity in the high-flow sea area is 3~5m / s.

2. 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.

3. 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 precipitated and filtered seawater and fully dissolving it; the third nutrient solution is prepared by adding the third nutrient component to precipitated and filtered seawater and fully dissolving it.

4. 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 of the seedling cultivation in step S1 is: (1) Phase 1: Apply the first nutrient solution once a day; (2) Second stage: Apply the first nutrient solution twice a day with an interval of 5 to 6 hours between the two applications; (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.

5. 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.

6. The fertilization method for promoting the growth of Sargassum seedlings according to claim 5, characterized in that: The method for applying the second / third nutrient solution is as follows: prepare a plurality of small bottles each provided with a plurality of small holes; quickly dispense the second / third nutrient solution into the small bottles and seal them; weight the small bottles with weights and then hang the bottles evenly spaced under a seedling rope, seedling curtain, or cultivation cable; and regularly replace the second / third nutrient solution in the small bottles.

7. 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 no less than 10 L / min / m 3 Aeration culture.

8. 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, water depth not exceeding 10m, water transparency not less than 1m, and excellent water quality.

9. 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, water depth not exceeding 10m, water transparency not less than 1m, and excellent water quality.

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