A method for applying active microalgae organic fertilizer

Abstract

The application discloses a kind of active microalgae organic fertilizer application methods, comprising the following steps: in microalgae liquid or microalgae and the mixed liquid of bacteria is added water-absorbing adhesive material, stirring is set time, so that water-absorbing adhesive material adheres microalgae or microalgae and bacteria mixture;Seed is filled in soil, and is watered, then the area close to seed is covered with water-absorbing adhesive material of adhered microalgae or microalgae and bacteria mixture, while 30%-60% of water-absorbing adhesive material is buried in soil, other parts are exposed to air.Using this method can maintain the high activity growth advantage of microalgae, so that it continuously plays the functions of bacteria regulation, fertilizer slow release, moisture retention and the like.

Description

Technical Field

[0001] This invention belongs to the field of organic fertilizer application technology, specifically relating to a method for applying active microalgae organic fertilizer. Background Technology

[0002] The statements herein provide only background information in relation to this invention and do not necessarily constitute prior art.

[0003] Fertilizer application is a common way to address nitrogen and phosphorus deficiency in soil. However, the amount of fertilizer used is difficult to control precisely, and over-fertilization is quite common, resulting in resource waste. Secondly, fertilizers are easily lost. Nitrogen and phosphorus nutrients in fertilizers have high solubility in soil and are easily washed away by rainwater or irrigation water, leading to poor fertilization effects. Furthermore, the lost fertilizer entering rivers and other water bodies can contribute to eutrophication. Finally, long-term application of fertilizers can damage soil aggregate structure, leading to soil compaction, increased aeration and permeability, and consequently affecting the activity of soil microorganisms, reducing the decomposition and accumulation of organic matter.

[0004] Microalgae fertilizers are environmentally friendly, improving crop productivity and reducing pollution from synthetic fertilizers. Among various types of biofertilizers, formulations based on photosynthetic organisms (including eukaryotic microalgae, anaerobic phototrophs, and cyanobacteria) are becoming increasingly important due to their efficient soil fertility maintenance and plant growth-promoting effects. Studies have shown that microalgae can enhance plant immunity; for example, cyanobacteria can produce hydrolytic enzymes and bactericidal substances (such as benzoic acid), which can disrupt cell membranes, inhibit protein synthesis, and have antagonistic effects against various plant pathogens. Secondly, microalgae contain various types of organic matter and polysaccharides, which can promote soil particle aggregation, form a good soil structure, increase soil porosity and aeration, and polysaccharides can also form a protective film on the surface of soil particles, reducing water evaporation and thus improving soil water retention capacity. In addition, the release of extracellular polymeric substances (EPS) from microalgae provides microorganisms with abundant carbon and nitrogen sources and other prebiotics, regulating the composition of bacterial communities and phosphorus-solubilizing and nitrogen-fixing functions to promote plant growth.

[0005] Microalgae fertilizer products are mainly in the form of dried algae powder. Generally, the dried algae powder is mixed with the soil before crop planting and used as a base fertilizer. Because microalgae lose some of their biological activity during the drying process, they lack microbial activity in the soil, and their nutrient release effect may not be as good as that of fresh algae liquid. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the purpose of this invention is to provide a method for applying active microalgae organic fertilizer. This method maintains the high activity and growth advantage of microalgae, allowing them to continuously exert their functions such as bacterial regulation, slow-release of nutrients, and moisture retention.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0008] A method for applying active microalgae organic fertilizer includes the following steps:

[0009] Add a water-absorbing adhesive to the microalgae solution or a mixture of microalgae and bacteria, stir for a set time, and allow the water-absorbing adhesive to adhere to the microalgae or the mixture of microalgae and bacteria.

[0010] Bury the seeds in the soil and water them. Then cover the area near the seeds with a water-absorbing material that attaches microalgae or a mixture of microalgae and bacteria, burying 30%-60% of the material in the soil while leaving the rest exposed to the air.

[0011] Microalgae need to be exposed to light in the top layer of soil to continue growing; when microalgae are placed near seeds, they can easily provide nutrients to the seeds.

[0012] In some embodiments, the microalgae are Chlorella, Scenedesmus, Haematococcus pluvialis, or Dunaliella salina.

[0013] In some embodiments, the bacteria are rhizobia, nitrogen-fixing bacteria, phosphate-solubilizing bacteria, mycorrhizal fungi, plant hormone-producing bacteria, biocontrol bacteria, ACC deaminase bacteria, or bacteria that promote the decomposition of organic matter.

[0014] In some embodiments, the method further includes the step of culturing and expanding the microalgae in a culture medium, wherein the culture medium is a microalgae culture medium rich in nitrogen and phosphorus.

[0015] Preferably, during the microalgae propagation process, the nitrogen source of the culture medium is KNO3, the phosphorus source is NaH2PO4, the nitrogen concentration is 30-60 mg / L, and the phosphorus concentration is 3-8 mg / L.

[0016] Preferably, the microalgae propagation time is 3-5 days, the propagation water temperature is above 20℃, and the algae are stirred regularly or irregularly.

[0017] In some embodiments, the absorbent adhesive material is cotton fiber, viscose fiber, bamboo fiber, lyocell, or polyvinyl alcohol fiber (PVA).

[0018] Preferably, the absorbent material is in the form of strips, with 40-200 strips per strip, each strip being 2-5cm long.

[0019] For further optimization, 40-60 shares are grouped into one unit.

[0020] Preferably, each seed is applied with 3-5 strands of absorbent attachment material consisting of attached microalgae or a mixture of microalgae and bacteria.

[0021] In some embodiments, a water-absorbing adhesive material is added to the culture medium, and the mixture is stirred for 10-30 minutes.

[0022] The beneficial effects achieved by one or more embodiments of the present invention described above are as follows:

[0023] After seeds are sown in the soil, the soil is covered and watered. Then, cotton threads that absorb microalgae (or algae-bacteria) are placed on the surface, with some threads buried in the soil and others exposed to the air. This process allows the microalgae to maximize their exposure to sunlight, while the cotton threads continuously absorb and store water from the soil or rainfall, serving as a source of water and nutrients for the algae. The above-ground portion creates a unique microenvironment, continuously supplying carbon dioxide and light, ensuring the microalgae's sustained growth. The photosynthesis of the microalgae also increases carbon sequestration. Some microalgae enter the soil surface with the cotton threads, remaining active and coexisting with bacteria, while others die, releasing organic matter, nitrogen, and phosphorus. The microalgae on the cotton threads (outside the soil) continue to grow, continuously converting chemical fertilizers into slow-release biological fertilizers, preventing runoff loss and river pollution.

[0024] Using microalgae fertilizers can also improve the utilization rate of carbon dioxide in the air, reduce the application of organic fertilizers and nitrogen and phosphorus fertilizers, alleviate the problem of large-scale loss of fertilizers in a short period of time, and is more environmentally friendly and economical. It enhances the stability of the soil ecosystem; the symbiotic relationship between microalgae and soil microorganisms helps to build a more stable and healthy soil ecosystem, improving the soil's resilience and self-repair capabilities. When large amounts of nitrogen and phosphorus pollution sources enter the soil, active microalgae can act as a biological barrier, quickly fixing nitrogen and phosphorus in the water and soil, and subsequently releasing them slowly into the soil, playing a buffering role. Active microalgae are rich in water and sugars, providing a water- and fertilizer-rich microenvironment for bacteria, and working together with functional bacteria to achieve better plant growth promotion and soil fertilization. Microalgae sugars also serve as a way to retain water in arid soils.

[0025] The production end produces microalgae concentrate, and the user end expands the culture and applies it as an attachment. This model avoids the cost of transporting and storing large amounts of liquid fertilizer. The active attached microalgae has efficient water and nutrient locking and anti-loss functions, strong slow-release effect, and more efficient and long-lasting fertilization function, which has good prospects for promotion. Attached Figure Description

[0026] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0027] Figure 1 This is a schematic diagram of the method for applying active microalgae organic fertilizer according to an embodiment of the present invention; wherein, 1-active microalgae; 2-plant seeds; 3-soil; 4-hydrophilic and non-toxic material; 5-sunlight; 6-plant seedlings.

[0028] Figure 2The effect of Chlorella exocrine secretions (EPS) on wheat stem length, root length, and dry weight is shown. *DW represents the blank control group; B indicates the presence of bacteria.

[0029] Figure 3 A comparative diagram showing the effects of Chlorella exocrine secretions on wheat photosynthesis;

[0030] Figure 4 A comparative graph showing the effects of microalgae survival on wheat stem length (a) and root length (b) in the presence of bacteria;

[0031] Figure 5 This is a comparative graph showing the effect of microalgal survival on wheat photosynthesis in the presence of bacteria. MA represents active microalgae, and IPS represents microalgal endosperm, i.e., cell disruption and inactive microalgae. Detailed Implementation

[0032] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0033] The present invention will be further described below with reference to the embodiments.

[0034] Example 1

[0035] 1) Microalgae and wheat species

[0036] The microalgae used in this experiment was Chlorella vulgaris FACHB-415, which was purchased from the Freshwater Algae Culture Collection of the Chinese Academy of Sciences.

[0037] The wheat variety used in this experiment was Lumai 15 (TAL Yangmai (No.1BI / 757318)FI / / 104-14). Wheat seeds of similar size and shape with plump grains were selected for the study.

[0038] 2) Microalgae culture

[0039] The algal culture was placed in a biochemical incubator (HYG-A double-layer full-temperature shaker; Peiying, Suzhou, China) and cultured on BG11 medium at a temperature of 25±0.5℃ and a rotation speed of 120RPM. An LED lamp (220V, 16W; Philips, Netherlands) was used as the light source with a light intensity of 4000 lux and a photoperiod of 12h:12h.

[0040] Chlorella cell density reaches 10 7At a concentration of cells / mL, the sample was centrifuged at 17217g for 10 minutes to obtain the supernatant (EPS) and lower precipitate of Chlorella. The lower precipitate was washed three times with distilled water and dissolved in distilled water. Under aseptic conditions, the concentrated algal solution was dispensed into 50mL vials for later use.

[0041] 3) Microalgae attachment

[0042] Preparation of microalgae attachment materials: cotton strips, 50 strands per strip, each strip 5cm long, 2500 strips per package.

[0043] Preparation of culture medium powder for microalgae propagation: Prepare a culture medium powder with nitrogen and phosphorus concentrations suitable for microalgae, N:P 8:1, TN 40mg (KNO3), TP 5mg (NaH2PO4), and 1 part of A5 reagent.

[0044] The formula for reagent A5 is: boric acid 2.86 g / L, manganese chloride 1.81 g / L, zinc sulfate 0.222 g / L, copper sulfate 0.079 g / L, sodium molybdate 0.39 g / L, and cobalt nitrate 0.0494 g / L.

[0045] Preliminary Preparations - Rough-Scale Microalgae Expansion and Attachment: Prepare microalgae liquid culture medium yourself. Add 1L of tap water to each portion of culture medium powder, pour in the microalgae concentrate, and then place it indoors / outdoors for expansion for 5 days until the Chlorella cell density reaches 102. 7 cells / mL. It is recommended to culture under strong light or indoor light conditions, with a water temperature above 20.0℃, and to stir regularly / irregularly.

[0046] Before harvesting, add cotton threads and stir continuously for 20 minutes until the white threads turn light green, indicating that microalgae and microalgae culture solution have adhered.

[0047] 4) Wheat seed culture

[0048] Wheat seeds were cleaned and disinfected by soaking in a 75% alcohol solution for 8 minutes, and then rinsed 3 times with sterile distilled water.

[0049] Indoor potted plants, plant growing room, 25℃, light-dark ratio 16:8 (16 hours of light, 8 hours of darkness), magnesium lamp, light intensity 10000Lx.

[0050] The wheat seeds were divided into three groups of 20 seeds each.

[0051] Group 1: Three cotton lines of microalgae and microalgae culture solution prepared in step (3) are buried above each seed. 50% of the cotton lines are buried in the soil and 50% are exposed to light.

[0052] The second group: three cotton lines of microalgae and microalgae culture solution prepared in step (3) are buried above each seed, and 100% of the cotton lines are buried in the soil.

[0053] The third group was a blank control group, with no microalgae added.

[0054] After two weeks of cultivation, relevant measurements of the wheat plants were taken.

[0055] After the addition of fresh Chlorella, the stem length, root length and dry weight of the wheat plants in the second group were significantly increased by 20%, 25% and 15% respectively compared with the group without Chlorella (P<0.05).

[0056] The stem length, root length, and dry weight of wheat plants in the first group were significantly increased by 30%, 33%, and 27%, respectively, compared with the group without Chlorella (P<0.05).

[0057] This indicates that the addition of fresh Chlorella significantly improved wheat growth indicators and promoted wheat growth and development to a certain extent. Furthermore, when using the application method of this invention—that is, burying half of the cotton thread with attached Chlorella in the soil and exposing the other half to sunlight—the wheat plants grew even better.

[0058] 5) To further investigate the activity of Chlorella and the growth-promoting mechanism of different components on plants, the effects of microalgal extracellular secretions (EPS) and intracellular contents (IPS) on plants were analyzed. The supernatant, i.e., EPS solution, was obtained by filtering the microalgal culture medium after 5 days of amplification.

[0059] A solution with the same N and P concentrations as the Chlorella supernatant (TN = 62.85 mg / L, TP = 1.68 mg / L, named NP group) was prepared as a control to investigate the role of extracellular secretion of organic matter by Chlorella.

[0060] In the experimental group, 15 mL of EPS solution and two seeds were added to each test tube and cultured for 7 days at 25°C with a light-dark ratio of 16:8 (16 hours of light and 8 hours of darkness) under a magnesium lamp with a light intensity of 10000 Lx; 6 parallel groups were set up.

[0061] In the control group, 15 mL of NP group solution and two seeds were added to each test tube and cultured for 7 days at 25°C with a light-dark ratio of 16:8 under a magnesium lamp at a light intensity of 10000 Lx. Six parallel groups were set up. Both groups simulated natural conditions and no environmental bacterial control was performed, meaning that bacteria were present in both groups (represented by the letter B in the figure).

[0062] like Figure 2 , Figure 3 As shown, the root length, stem length, and dry weight of wheat treated with microalgae EPS solution were 13.55 cm, 10.95 cm, and 1.4 × 10⁻⁶ cm, respectively. -2Compared with wheat cultured with N and P solutions, the growth rate of microalgae EPS increased significantly by 42.21%, 22.07%, and 24.78% (p<0.05), respectively. The photosynthetic parameter Y(II) increased by 57.56%, and the Fv / Fm ratio also increased slightly (p<0.05). Hormone indicators IAA, GA, and CTK increased by 15.66%, 54.08%, and 75.12%, respectively. This indicates that microalgae EPS has a good promoting effect on plant growth.

[0063] Chlorella cells that have undergone cell disruption treatment (IPS group) were compared with live microalgae that have not undergone disruption treatment (MA group) to explore the difference in the effects of continuous release of EPS or one-time release of cell contents (IPS) by Chlorella, and to demonstrate the influence of microalgae activity on plant growth.

[0064] IPS group: The microalgae solution after 5 days of amplification was ultrasonically disrupted to obtain liquid; 15 ml of liquid was added to a test tube, along with two wheat seeds, and cultured for 7 days at 25°C with a light-dark ratio of 16:8 (16 hours of light and 8 hours of darkness) under a magnesium lamp with a light intensity of 10000 Lx. Six parallel groups were used.

[0065] MA group: Take 15ml of fresh microalgae solution after 5 days of amplification, add it to a test tube, add two wheat seeds, and culture for 7 days at 25℃ with a light-dark ratio of 16:8 (16 hours of light and 8 hours of darkness), using a magnesium lamp with a light intensity of 10000Lx, in 6 parallel groups.

[0066] Experimental results showed that wheat grew better under uncontrolled microalgae conditions than under uncontrolled IPS microalgae conditions, with root length, stem length, and dry weight of 13.43 cm, 13.50 cm, and 1.35 × 10⁻⁶ cm, respectively. -2 g( Figure 4 Compared with the Chlorella IPS group, the chlorophyll content increased by 20.99%, 27.97%, and 35.18%, respectively (p<0.05). The chlorophyll fluorescence indices Fv / Fm and Y(II) increased by 3.51% and 26.67%, respectively. Figure 5 The contents of plant-related growth hormone indicators IAA, GA, and CTK also increased significantly by 17.34%, 72.50%, and 48.47%, respectively (p<0.05). This indicates that the material exchange and metabolic processes between active algae and bacteria play an important role in the growth and development of wheat, and have a good growth-promoting effect, meaning that active algae are superior to inactive algae.

[0067] 6) To investigate the retention of Chlorella activity, the number of live Chlorella in the MA group solution after wheat culture in step 5) was counted using the BG11 agar plate counting method after the experiment.

[0068] The results showed that after wheat culture, the number of live algae in the hydroponic solution of the MA group could reach 10.7 The concentration of cfu / mL remained similar to that at the initial stage of the experiment, indicating that Chlorella can maintain good activity in the algae-bacterial symbiotic system, thereby continuously releasing EPS into the environment. During the cultivation process, both the live microalgae and rhizosphere bacteria produced plant hormones, polysaccharides, and other active substances beneficial to plant growth. The two played a synergistic role in wheat growth, significantly improving the growth effect of wheat.

[0069] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for applying active microalgae organic fertilizer, characterized in that: Includes the following steps: Add a water-absorbing adhesive to the microalgae solution or a mixture of microalgae and bacteria, stir for a set time, and allow the water-absorbing adhesive to adhere to the microalgae or the mixture of microalgae and bacteria. The seeds are buried in the soil and watered. Then, the area near the seeds is covered with a water-absorbing material that attaches microalgae or a mixture of microalgae and bacteria, with 30%-60% of the material buried in the soil and the rest exposed to the air. The absorbent material is cotton fiber, viscose fiber, bamboo fiber, lyocell, or polyvinyl alcohol fiber (PVA). The absorbent material is in the form of strips, with 40-200 strips per strip, each strip being 2-5 cm long.

2. The method for applying active microalgae organic fertilizer according to claim 1, characterized in that: The microalgae are Chlorella, Scenedesmus, Haematococcus pluvialis, or Dunaliella salina.

3. The method for applying active microalgae organic fertilizer according to claim 1, characterized in that: The bacteria are rhizobia, nitrogen-fixing bacteria, phosphate-solubilizing bacteria, mycorrhizal fungi, plant hormone-producing bacteria, biocontrol bacteria, ACC deaminase bacteria, or bacteria that promote the decomposition of organic matter.

4. The method for applying active microalgae organic fertilizer according to claim 1, characterized in that: It also includes the steps of culturing and expanding microalgae in a culture medium rich in nitrogen and phosphorus.

5. The method for applying active microalgae organic fertilizer according to claim 4, characterized in that: During the microalgae propagation process, the nitrogen source of the culture medium is KNO3, and the phosphorus source is NaH2PO4. The concentration of KNO3 is 30-60 mg / L, and the concentration of NaH2PO4 is 3-8 mg / L.

6. The method for applying active microalgae organic fertilizer according to claim 4, characterized in that: The microalgae propagation time is 3-5 days, the water temperature for propagation is above 20℃, and it should be stirred regularly or irregularly.

7. The method for applying active microalgae organic fertilizer according to claim 1, characterized in that: Add a water-absorbing adhesive to the culture medium and stir for 10-30 minutes.

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