A cultivation substrate, its preparation method and application

Abstract

This invention provides a cultivation substrate, its preparation method, and its application, belonging to the field of tailings utilization technology. The cultivation substrate, by weight, comprises: 1-7 parts of an algae-bacterial symbiosis, 1-12 parts of modified illite tailings, and 1-22 parts of sheep manure; the algae-bacterial symbiosis includes *Chlorella vulgaris* and *Streptomyces flavus*. The cultivation substrate provided by this invention meets the requirements of standard NY / 2118-2012 for vegetable seedling substrates, improving soil physicochemical properties while also promoting plant growth and enhancing plant stress resistance. The cultivation substrate provided by this invention has advantages such as environmental friendliness and sustainable utilization, aligning with the development trend of modern agriculture, and providing a new direction for the resource utilization of illite tailings; it also achieves efficient recycling of mine tailings and agricultural waste, providing an innovative path for green agricultural development and resource utilization.

Description

Technical Field

[0001] This invention belongs to the field of tailings utilization technology, specifically relating to a cultivation substrate, its preparation method, and its application. Background Technology

[0002] Illite tailings are a large amount of solid waste generated during the mining and processing of illite. However, tailings storage not only occupies land but can also cause environmental pollution. Therefore, realizing their resource utilization is of great significance for reducing solid waste accumulation and environmental burden. However, current technologies for utilizing illite tailings are relatively lacking, and technologies for the comprehensive utilization of illite tailings still need to be developed. Summary of the Invention

[0003] The purpose of this invention is to provide a cultivation substrate that uses illite tailings as one of the main raw materials, which can not only reduce the environmental burden, but also improve the soil and promote plant growth.

[0004] The objective of this invention is achieved through the following technical solution:

[0005] This invention provides a cultivation substrate, comprising, by weight:

[0006] 1-7 parts of algae-bacteria symbiosis, 1-12 parts of modified illite tailings, and 1-22 parts of sheep manure;

[0007] The algae-bacterial symbiosis includes Chlorella and Streptomyces flavus.

[0008] Preferably, the method for preparing the algae-bacteria symbiont includes:

[0009] After inoculating Chlorella and Streptomyces flavus into a culture medium and co-amplifying them, the algae-bacterium symbiosis was obtained.

[0010] Preferably, the Chlorella includes Chlorella FACHB-28; the Streptomyces flavus includes Streptomyces flavus with accession number CGMCC4.6556.

[0011] Preferably, during inoculation, the volume ratio of Chlorella algae solution to Streptomyces flavus bacterial solution is (3-5):1; the density of Chlorella in the Chlorella algae solution is 1×10⁻⁶. 6 The bacterial count of *Streptomyces flavus* in the bacterial culture was 2 × 10⁶ cells / mL. 8 CFU / mL.

[0012] Preferably, the amplification culture is carried out under light for 12-14 hours / day, with a light intensity of 5000-5500 Lux, a temperature of 25-28°C, and a duration of 10-12 days.

[0013] Preferably, the method for preparing the modified illite tailings includes:

[0014] The illite tailings were crushed, dried, and then calcined in stages to obtain the modified illite tailings.

[0015] The segmented calcination includes a first calcination and a second calcination;

[0016] The temperature of the first calcination is 150–250°C; the time of the first calcination is 1–3 hours.

[0017] The second calcination temperature is 400–500℃; the second calcination time is 1.5–3 hours.

[0018] Preferably, the drying temperature is ≤40°C.

[0019] This invention provides a method for preparing the cultivation substrate described in the above technical solution, comprising the following steps:

[0020] The cultivation substrate is obtained by mixing algae-bacteria symbiosis, modified illite tailings and sheep manure and then fermenting the mixture.

[0021] Preferably, the fermentation temperature is 25–40°C and the time is 10–15 days.

[0022] This invention provides the application of the cultivation substrate described in the above technical solution or the cultivation substrate prepared by the preparation method described in the above technical solution in any one or more of the following aspects (1) to (4):

[0023] (1) Improve the soil;

[0024] (2) Promotes seed germination and increases seed germination rate;

[0025] (3) Improve plant stress resistance;

[0026] (4) Promote plant growth.

[0027] The beneficial effects of this invention are:

[0028] This invention provides a cultivation substrate, comprising, by weight: 1-7 parts of an algae-bacterial symbiosis, 1-12 parts of modified illite tailings, and 1-22 parts of sheep manure; the algae-bacterial symbiosis includes Chlorella vulgaris and Streptomyces flavus. The sheep manure in the cultivation substrate replenishes organic matter in the soil and provides nutritional support for the growth of the algae-bacterial symbiosis; the Chlorella vulgaris and Streptomyces flavus in the algae-bacterial symbiosis, through synergistic action, secrete bioactive substances, improve the soil microecological environment, and activate minerals such as potassium, calcium, iron, magnesium, and sodium in illite tailings, increasing the number of microorganisms and improving soil quality, while simultaneously realizing the resource utilization and high-value utilization of illite tailings; the modified illite tailings can achieve slow release of mineral nutrients, water retention and aeration, pH adjustment, and enhanced stability of the cultivation substrate. The cultivation substrate provided by this invention meets the requirements of standard NY / 2118-2012 for vegetable cultivation substrates. While improving soil physicochemical properties, it also promotes plant growth and enhances plant stress resistance. In summary, the cultivation substrate provided by this invention has advantages such as environmental friendliness and sustainable utilization, aligning with the development trend of modern agriculture. It also provides a new direction for the resource utilization of illite tailings; furthermore, it achieves efficient recycling of mine tailings and agricultural waste, providing an innovative path for green agricultural development and resource utilization. Detailed Implementation

[0029] This invention provides a cultivation substrate, comprising, by weight:

[0030] 1-7 parts of algae-bacteria symbiosis, 1-12 parts of modified illite tailings, and 1-22 parts of sheep manure;

[0031] The algae-bacterial symbiosis includes Chlorella and Streptomyces flavus.

[0032] In this invention, the cultivation substrate comprises 1 to 7 parts by weight of an algae-bacterial symbiotic. As an optional embodiment of this invention, the algae-bacterial symbiotic can be 1, 2, 3, 4, 5, 6, or 7 parts. In this invention, the algae-bacterial symbiotic includes *Chlorella vulgaris* and *Streptomyces flavus*. As an optional embodiment of this invention, the *Chlorella vulgaris* includes *Chlorella vulgaris* FACHB-28; the *Streptomyces flavus* includes *Streptomyces flavus* with accession number CGMCC 4.6556. The cultivation substrate provided by this invention combines *Chlorella vulgaris* and *Streptomyces flavus*. As a symbiotic organism, both secrete bioactive substances, which synergistically activate minerals such as potassium, calcium, iron, magnesium, and sodium in illite tailings, enhance microbial activity in the cultivation substrate, thereby improving soil carbon sequestration, improving the soil microenvironment, providing the necessary nutrients for plant growth, and thus promoting seed germination and increasing plant resistance.

[0033] This invention does not specifically limit the preparation method of the algae-bacterial symbiont; any conventional preparation method in the art can be used. As an optional embodiment of this invention, the preparation method of the algae-bacterial symbiont includes: inoculating *Chlorella* and *Streptomyces flavus* into a culture medium for co-expansion culture to obtain the algae-bacterial symbiont. In this invention, the culture medium comprises: 1.5 g / L sodium nitrate, 40 mg / L dipotassium hydrogen phosphate trihydrate, 80 mg / L magnesium sulfate heptahydrate, 36 mg / L calcium chloride dihydrate, 20 mg / L sodium carbonate, 1 mg / L disodium EDTA, 0.72 mg / L ferric chloride hexahydrate, 6 mg / L citric acid, 6 mg / L ferric ammonium citrate, 3 mg / L boric acid, 2 mg / L manganese chloride tetrahydrate, 0.2 mg / L zinc sulfate heptahydrate, 0.08 mg / L copper sulfate pentahydrate, and 0.05 mg / L cobalt nitrate hexahydrate. As an optional embodiment of the present invention, the pH of the culture medium can be 6.5–7.5, or 6.5, 6.6, 6.7, 6.8, 6.9, 7.0, 7.1, 7.2, 7.3, 7.4, or 7.5. As an optional embodiment of the present invention, during inoculation, the volume ratio of *Chlorella vulgaris* algal solution to *Streptomyces flavus* bacterial solution can be (3–5):1, or 3:1, 4:1, or 5:1; the density of *Chlorella vulgaris* in the algal solution is 1 × 10⁻⁶. 6 The bacterial count of *Streptomyces flavus* in the bacterial culture was 2 × 10⁶ cells / mL. 8 CFU / mL. As an optional embodiment of the present invention, the photoperiod of the amplification culture is 12–14 h / d, which can be 12, 13, or 14 h / d; the light intensity of the amplification culture is 5000–5500 Lux, which can be 5000, 5100, 5200, 5300, 5400, or 5500 Lux; the temperature of the amplification culture is 25–28°C, which can also be 26°C; and the amplification culture time is 10–12 days, which can be 10, 11, or 12 days. During the amplification culture, it is preferable to shake the flask three times a day, more preferably once each in the morning, noon, and evening, to provide dissolved oxygen for the culture of *Chlorella vulgaris* and *Streptomyces flavus*. After the amplification culture is completed, the present invention obtains an algae-bacterium symbiosis.

[0034] In this invention, based on the mass fraction of the algae-bacterial symbiosis, the cultivation substrate includes 1 to 12 parts of modified illite tailings. As an optional embodiment of this invention, the modified illite tailings can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12 parts. This invention does not specifically limit the preparation method of the modified illite tailings; any conventional preparation method in the art can be used. The modified illite tailings have the functions of slow-release mineral nutrients (releasing elements such as potassium, magnesium, and silicon), optimizing soil physical structure, and regulating soil pH stability. Using it as a component of the cultivation substrate is environmentally friendly and long-lasting, possessing the dual value of efficient agricultural production and ecological restoration of mining areas.

[0035] As an optional embodiment of the present invention, the preparation method of the modified illite tailings includes: crushing and drying the illite tailings, followed by segmented calcination to obtain the modified illite tailings; the segmented calcination includes a first calcination and a second calcination; the temperature of the first calcination can be 150-250℃; the time of the first calcination can be 1-3 hours; the temperature of the second calcination can be 400-500℃; and the time of the second calcination can be 1.5-3 hours. The present invention does not specifically limit the source of the illite tailings; products from conventional sources in the art can be used. In this embodiment, illite tailings purchased from Inner Mongolia, whose main component is aluminum silicate hydrate, and which also contains quartz, feldspar, and a small amount of clay minerals, are used as an example to specifically illustrate the technical solution of the present invention. After obtaining the illite tailings, the present invention preferably crushes the illite tailings. The present invention does not specifically limit the crushing method; conventional crushing methods in the art can be used. After obtaining the pulverized illite tailings, the present invention preferably sieves the obtained illite tailings; the sieve aperture can be 60 mesh. The present invention preferably washes and then dries the sieved illite tailings. The present invention does not specifically limit the washing method; any conventional washing method in the art can be used. As an optional embodiment of the present invention, the washing method can be to wash away surface impurities of the illite tailings with ultrapure water. As an optional embodiment of the present invention, the drying method includes baking; the drying temperature can be ≤40℃, or 30~40℃, or 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, or 40℃; the drying time can be 24 hours. The drying process of the illite tailings in the present invention needs to be carried out at a temperature below 40℃. Excessively high drying temperatures will affect the physical structure, chemical composition, and stability of the illite tailings, impacting subsequent use.

[0036] After drying, the present invention performs segmented calcination on the dried illite tailings. As an optional embodiment of the present invention, the segmented calcination includes a first calcination and a second calcination; the temperature of the first calcination can be 150–250°C, or 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, or 250°C; the time of the first calcination can be 1–3 hours, or 1, 2, or 3 hours; the temperature of the second calcination can be 400–500°C, or 400, 410, 420, 430, 440, 450, 460, 470, 480, 490, or 500°C; the time of the second calcination can be 1.5–3 hours, or 1.5, 2, 2.5, or 3 hours. The first calcination of the illite tailings in this invention mainly removes surface adsorbed water and organic impurities; it can cause some interlayer cations (such as K+) in the illite tailings to migrate and form defect sites, increasing the specific surface area. The second calcination of the illite tailings in this invention mainly decomposes the carbonate minerals in the illite tailings, and can also remove hydroxyl groups from the illite tailings to induce lattice distortion and generate active Al-OH / Si-OH groups. After the segmented calcination is completed, the modified illite tailings are obtained. The main purpose of the modification of illite tailings by the above method in this invention is: (1) Physical modification: increase porosity (from the original 4.7% to 12.3%), enhance the water retention and air permeability of the matrix (2) Chemical modification: increase CEC (cation exchange capacity) from 12.4 cmol / kg to 18.6 cmol / kg, promote the slow release of nutrients (3) Passivation of toxic substances: convert heavy metals Cd and Pb from the exchangeable state to the residue state.

[0037] In this invention, based on the mass fraction of the algae-bacterial symbiont, the cultivation substrate comprises 1 to 22 parts of sheep manure. As an optional embodiment of this invention, the sheep manure can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, or 22 parts. This invention does not specifically limit the source of the sheep manure; any source conventional in the art can be used. The sheep manure particles in the cultivation substrate provided by this invention are fine and rich in nutrients, providing nutritional support for the growth of the algae-bacterial symbiont while also replenishing the soil with organic matter, thereby improving soil nutrients.

[0038] The cultivation substrate provided by this invention meets the requirements of standard NY / 2118-2012 for vegetable seedling substrates. It can improve the physical and chemical properties of the soil, and also promote plant growth and enhance plant stress resistance.

[0039] This invention provides a method for preparing the cultivation substrate described in the above-mentioned technical solution, comprising the following steps: mixing algae-bacterial symbiosis, modified illite tailings, and sheep manure evenly, followed by fermentation to obtain the cultivation substrate. This invention does not specifically limit the mixing method; any conventional mixing method in the art can be used. After mixing, this invention preferably obtains a mixed system. After obtaining the mixed system, this invention preferably adjusts the initial moisture content of the mixed system. As an optional embodiment of this invention, the initial moisture content can be 50%–55%, or 50%, 51%, 52%, 53%, 54%, or 55%. This invention does not specifically limit the method for adjusting the initial moisture content; any conventional method in the art can be used. In an optional embodiment of this invention, the method for adjusting the initial moisture content includes: if the moisture content is too high, drying can be performed using a drying auxiliary device; if the moisture content is too low, water can be added to adjust it; the drying auxiliary device includes a dryer. As an optional embodiment of the present invention, the fermentation temperature can be 25–40°C, or 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, or 40°C; the fermentation time can be 10–15 days, or 10, 11, 12, 13, 14, or 15 days. As an optional embodiment of the present invention, the compost is turned during the fermentation process; the turning can be done every two days starting from the 5th day. After fermentation is completed, the present invention yields a cultivation substrate.

[0040] This invention, through fermentation, allows the algae-bacterial symbiotic to humify organic matter in sheep manure, such as cellulose and lignin, generating humic acid. This improves the aggregate structure of the cultivation substrate. Simultaneously, fermentation activates and modifies minerals such as potassium, calcium, iron, magnesium, and sodium in illite tailings, transforming insoluble substances into forms easily absorbed and utilized by plants. Furthermore, the algae-bacterial symbiotic can act as a microbial agent to enhance microbial activity in the cultivation substrate. The cultivation substrate obtained through fermentation in this invention has a high degree of humification, high nutrient content, and high microbial activity. Adding it to soil helps improve soil aggregate structure, increase soil nutrients, and improve soil physicochemical properties. Moreover, the nutrients in the cultivation substrate are more easily absorbed and utilized by plants, thus promoting plant growth.

[0041] The bulk density of the cultivation substrate provided by this invention is 0.3–0.5 g / cm³. 3The total porosity is 65%–75%, the aeration porosity is 20%–25%, the water-holding porosity is 50%–62%, the air-to-water volume ratio is 1:(2–3), the relative moisture content is 20%–25%, the cation exchange capacity is 20–30 cmol / kg, the particle size is 10–15 mm, the pH is 6–7, the electrical conductivity is 0.1–0.2 mS / cm, the organic matter content is 60%–70%, the hydrolyzable nitrogen is 78–100 mg / kg, the available phosphorus is 13–50 mg / kg, and the available potassium is 150–200 mg / kg. The mass ratio of nitrate nitrogen to ammonium nitrogen is (4–6):1, the exchangeable calcium is 80–120 mg / kg, and the exchangeable magnesium is 30–80 mg / kg. All the above indicators meet the requirements of standard NY / 2118-2012 for vegetable cultivation substrates.

[0042] This invention provides the application of the cultivation substrate described in the above-described technical solution or the cultivation substrate prepared by the preparation method described in the above-described technical solution in any one or more of the following aspects (1) to (4):

[0043] (1) Improve the soil;

[0044] (2) Promotes seed germination and increases seed germination rate;

[0045] (3) Improve plant stress resistance;

[0046] (4) Promote plant growth.

[0047] The cultivation substrate provided by this invention can improve soil. The results of the embodiments of this invention show that the cultivation substrate can improve the physical and chemical properties of soil, thereby promoting plant growth and increasing the germination rate of plant seeds.

[0048] The cultivation substrate provided by this invention can promote seed germination. The results of the embodiments of this invention show that the cultivation substrate can promote seed germination and increase the seed germination rate. As an optional embodiment of this invention, the seeds include vegetable seeds; the vegetable seeds include rapeseed.

[0049] The cultivation substrate provided by this invention can improve plant stress resistance. In this invention, the stress resistance includes drought resistance and / or salt tolerance. As an optional embodiment of this invention, the plant includes vegetables; the vegetable includes bok choy.

[0050] The cultivation substrate provided by this invention can promote plant growth. This promotion of plant growth includes increasing plant height, fresh weight, and leaf chlorophyll content, or two or more of these. As an optional embodiment of this invention, the plant includes vegetables; the vegetables include bok choy.

[0051] To further illustrate the present invention, the technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0052] The raw materials used in the following technical solutions:

[0053] The illite tailings used in this invention were purchased commercially from Inner Mongolia. The main component is aluminum silicate hydrate, and it also contains quartz, feldspar, and a small amount of clay minerals. The heavy metal content of the illite tailings meets the national standards for heavy metal risk control in agricultural land soil (GB15618-2018). Specifically, mercury is 0.0815 mg / kg, arsenic is 1.58 mg / kg, lead is 16.89 mg / kg, cadmium is 16.89 mg / kg, and chromium is 29.270 mg / kg. The physicochemical properties of the illite tailings are as follows: total nitrogen content is 0.12 g / kg, total phosphorus content is 0.15 g / kg, total potassium content is 25.45 g / kg, available nitrogen content is 41.1 mg / kg, available phosphorus content is 0.78 mg / kg, available potassium content is 177.5 mg / kg, organic matter content is 1.7 g / kg, and pH value is 9.08.

[0054] The sheep manure used in this invention is purchased from ordinary commercial sources.

[0055] The culture medium used in this invention for algae-bacteria symbiosis consists of the following components: 1.5 g / L sodium nitrate, 40 mg / L dipotassium hydrogen phosphate trihydrate, 80 mg / L magnesium sulfate heptahydrate, 36 mg / L calcium chloride dihydrate, 20 mg / L sodium carbonate, 1 mg / L disodium EDTA, 0.72 mg / L ferric chloride hexahydrate, 6 mg / L citric acid, 6 mg / L ferric ammonium citrate, 3 mg / L boric acid, 2 mg / L manganese chloride tetrahydrate, 0.2 mg / L zinc sulfate heptahydrate, 0.08 mg / L copper sulfate pentahydrate, and 0.05 mg / L cobalt nitrate hexahydrate.

[0056] Example 1

[0057] A cultivation substrate, by weight, comprises: 1 part algae-bacterial symbiosis, 1 part modified illite tailings, and 2 parts sheep manure. The algae-bacterial symbiosis includes Chlorella vulgaris and Streptomyces flavus.

[0058] 1. The preparation method of algae-bacteria symbiont is as follows:

[0059] The Chlorella sp. FACHB-28 strain was purchased from the Freshwater Algae Culture Collection of the Chinese Academy of Sciences.

[0060] Streptomyces microflavus was purchased from the China General Microbiological Culture Collection Center, with accession number CGMCC 4.6556;

[0061] Take 150 mL of algae-bacterial symbiotic culture medium and place it in a 250 mL Erlenmeyer flask, then sterilize it at 120 °C for 2 hours. After the culture medium cools, adjust the pH to 6.5, then inoculate 60 mL of Chlorella algae solution and 20 mL of Streptomyces flavus bacterial solution in a sterile operating table. The density of Chlorella in the algae solution is 1 × 10⁻⁶. 6 The density of *Streptomyces flavus* in the bacterial culture was 2 × 10⁶ / mL. 8 Cells / mL. After inoculation, algae-bacterial amplification culture was carried out. During the algae-bacterial amplification culture, a light duration of 12 hours per day and a light intensity of 5000 Lux were ensured, and the flasks were shaken once each in the morning, noon and evening (to provide dissolved oxygen). The culture was carried out for 12 days at a temperature of 26℃ to obtain the algae-bacterial symbiosis.

[0062] 2. The preparation method of modified illite tailings is as follows:

[0063] Natural illite tailings were crushed and ground, then passed through a 60-mesh nylon sieve. After washing away surface impurities with ultrapure water, the tailings were dried in an oven at 40°C for 24 hours. Then, they were calcined at high temperature in two stages: first at 200°C for 2 hours, and then at 450°C for 2 hours, to obtain modified illite tailings.

[0064] 3. The preparation method of the cultivation substrate is as follows:

[0065] By weight, 1 part algae-bacterial symbiosis, 1 part modified illite tailings and 2 parts sheep manure are mixed to obtain a mixed system. The initial moisture content of the mixed system is adjusted to 50% to 55%, and fermented at 25℃ for 10 days. The mixture is turned over every two days from day 5 to day 10 of fermentation to obtain the cultivation substrate.

[0066] The bulk density of the cultivation substrate prepared by this invention is 0.34 g / cm³. 3 The total porosity is 75%, aeration porosity is 25%, water-holding porosity is 62%, air-to-water volume ratio is 1:3, relative moisture content is 20%, cation exchange capacity is 26 kmol / kg, particle size is 14 mm, pH is 6.7, electrical conductivity is 0.13 mS / cm, organic matter content is 63%, hydrolyzable nitrogen is 78 mg / kg, available phosphorus is 13 mg / kg, and available potassium is 150 mg / kg. The mass ratio of nitrate nitrogen to ammonium nitrogen is 5:1, exchangeable calcium is 103 mg / kg, and exchangeable magnesium is 73 mg / kg. All the above indicators meet the requirements of standard NY / 2118-2012 for vegetable cultivation substrates.

[0067] Example 2

[0068] A cultivation substrate, by weight, consists of: 1 part algae-bacterial symbiosis, 2 parts modified illite tailings, and 2 parts sheep manure.

[0069] 1. The preparation method of algae-bacteria symbiont is as follows:

[0070] The sources of Chlorella and Streptomyces flavus are the same as in Example 1.

[0071] Take 150 mL of algae-bacterial symbiotic culture medium and place it in a 250 mL Erlenmeyer flask, then sterilize it at 120 °C for 2 hours. After the culture medium cools, adjust the pH to 7.0, then inoculate 60 mL of Chlorella algae solution and 20 mL of Streptomyces flavus bacterial solution in a sterile operating table. The density of Chlorella in the Chlorella algae solution is 1 × 10⁻⁶. 6 The density of *Streptomyces flavus* in the bacterial culture was 2 × 10⁶ cells / mL. 8 Cells / mL. After inoculation, algae-bacterial amplification culture was carried out. During the algae-bacterial amplification culture, a 12-hour light period and a light intensity of 5200 Lux were ensured per day, and the flasks were shaken once each in the morning, noon and evening (to provide dissolved oxygen). The culture was carried out for 12 days at a temperature of 26℃ to obtain the algae-bacterial symbiont.

[0072] 2. The preparation method of modified illite tailings is the same as in Example 1.

[0073] 3. The preparation method of the cultivation substrate is as follows:

[0074] By weight, 1 part algae-bacterial symbiosis, 2 parts modified illite tailings and 2 parts sheep manure were mixed to obtain a mixed system. The initial moisture content of the mixed system was adjusted to 50% to 55%, and fermented at 25°C for 15 days. The mixture was turned over every two days from day 5 to day 15 of fermentation to obtain the cultivation substrate.

[0075] Example 3

[0076] A cultivation substrate, by weight, consists of: 1 part algae-bacteria symbiosis, 2 parts modified illite tailings, and 4 parts sheep manure.

[0077] 1. The preparation method of algae-bacteria symbiont is as follows:

[0078] The sources of Chlorella and Streptomyces flavus are the same as in Example 1.

[0079] Take 150 mL of algae-bacterial symbiotic culture medium and place it in a 250 mL Erlenmeyer flask, then sterilize it at 120 °C for 2 hours. After the culture medium cools, adjust the pH to 7.5, then inoculate 60 mL of Chlorella algae solution and 20 mL of Streptomyces flavus bacterial solution in a sterile operating table. The density of Chlorella in the Chlorella algae solution is 1 × 10⁻⁶. 6The density of *Streptomyces flavus* in the bacterial culture was 2 × 10⁶ cells / mL. 8 Cells / mL. After inoculation, algae-bacteria amplification culture was carried out. During the algae-bacteria amplification culture, a 12-hour light period and a light intensity of 5400 Lux were ensured per day, and the flasks were shaken once each in the morning, noon and evening (to provide dissolved oxygen). The culture was carried out for 12 days at a temperature of 26℃ to obtain the algae-bacteria symbiont.

[0080] 2. The preparation method of modified illite tailings is the same as in Example 1.

[0081] 3. The preparation method of the cultivation substrate is as follows:

[0082] By weight, 1 part algae-bacterial symbiosis, 2 parts modified illite tailings and 4 parts sheep manure were mixed to obtain a mixed system. The initial moisture content of the mixed system was adjusted to 50% to 55%, and fermented at 35℃ for 10 days. The mixture was turned over every two days from day 5 to day 10 of fermentation to obtain the cultivation substrate.

[0083] Comparative Example 1

[0084] A cultivation substrate, with the same composition and preparation method as in Example 2, the only difference being that when preparing the algae-bacterial symbiosis, 20 mL of Streptomyces flavus is replaced with 10 mL of Streptomyces flavus.

[0085] Comparative Example 2

[0086] A cultivation substrate, with the same composition and preparation method as in Example 2, except that in the preparation of the algae-bacteria symbiosis, Chlorella was replaced with an equal amount of Spirulina (purchased from the Freshwater Algae Culture Collection, Chinese Academy of Sciences, catalog number FACHB-971), and the density of Spirulina was 1×10⁻⁶. 6 per mL.

[0087] Comparative Example 3

[0088] A cultivation substrate, with the same composition and preparation method as in Example 2, except that the modified illite tailings are replaced with illite tailings that have only been washed. The specific preparation steps are as follows: take natural illite tailings, crush and grind them, pass them through a 60-mesh nylon sieve, wash away surface impurities with ultrapure water, and dry them in an oven at 50°C for 24 hours. After drying, the modified illite tailings are directly used to replace the modified illite tailings in the preparation of the cultivation substrate.

[0089] Comparative Example 4

[0090] A cultivation substrate, with the same composition and preparation method as in Example 2, except that in the modified illite tailings preparation method: natural illite tailings powder is ground and passed through a 60-mesh nylon sieve, and then surface impurities are washed away with ultrapure water and dried in an oven at 50°C for 24 hours; after drying, it is calcined at high temperature in two stages, first at 200°C for 2 hours, and then at 450°C for 2 hours, to obtain modified illite tailings.

[0091] Comparative Example 5

[0092] A cultivation substrate composed solely of sheep manure.

[0093] No other materials are added to the sheep manure. The sheep manure is composted and fermented at 25℃ for 15 days.

[0094] Comparative Example 6

[0095] A cultivation substrate, by weight, consists of only 2 parts sheep manure and 1 part algae-bacteria symbiotic, and the preparation method of the algae-bacteria symbiotic is the same as in Example 2.

[0096] Methods for preparing cultivation substrate:

[0097] Sheep manure and algae-bacteria symbiosis are mixed to obtain a mixed system. The initial moisture content of the mixed system is adjusted to 50% to 55%, and fermented at 25℃ for 15 days. The mixture is turned over every two days from day 5 to day 15 of fermentation to obtain the cultivation substrate.

[0098] Comparative Example 7

[0099] A cultivation substrate composed solely of modified illite tailings, the preparation method of which is the same as in Example 2.

[0100] Comparative Example 8

[0101] The composition and preparation method of a cultivation substrate are the same as in Example 1, the only difference being that sheep manure is replaced with chicken manure in Comparative Example 9.

[0102] A cultivation substrate composition and preparation method are the same as in Example 1, the only difference being that sheep manure is replaced with cow manure.

[0103] Comparative Example 10

[0104] Same as Example 2, except that the calcination at 450°C is replaced with calcination at 600°C, and the calcination time is 2 hours.

[0105] Comparative Example 11

[0106] Same as Example 2, except that the calcination at 450°C is replaced with calcination at 300°C, and the calcination time is 2 hours.

[0107] Comparative Example 12

[0108] Same as Example 2, except that the calcination at 200°C is omitted, and calcination is carried out directly at 450°C for 2 hours.

[0109] Comparative Example 13

[0110] Same as Example 2, except that the calcination at 450°C is omitted, and calcination is only carried out at 200°C for 2 hours.

[0111] Application Example 1

[0112] The cultivation substrates prepared in Examples 1-3 and Comparative Examples 1-13 were applied to a rapeseed seed germination experiment, and were divided into four groups: control group 1, experimental group 1, experimental group 2, experimental group 3, control group 1, control group 2, control group 3, control group 4, control group 5, control group 6, control group 7, control group 8, control group 9, control group 10, control group 11, control group 12, and control group 13. All groups used the same management method, with the following differences:

[0113] Blank group 1: No cultivation substrate added; Experimental group 1: Cultivation substrate prepared in Example 1 applied; Experimental group 2: Cultivation substrate prepared in Example 2 applied; Experimental group 3: Cultivation substrate prepared in Example 3 applied; Control group 1: Cultivation substrate prepared in Comparative Example 1 applied; Control group 2: Cultivation substrate prepared in Comparative Example 2 applied; Control group 3: Cultivation substrate prepared in Comparative Example 3 applied; Control group 4: Cultivation substrate prepared in Comparative Example 4 applied; Control group 5: Cultivation substrate prepared in Comparative Example 5 applied; Control group 6: Cultivation substrate prepared in Comparative Example 6 applied; and so on; Control group 13: Cultivation substrate prepared in Comparative Example 13 applied.

[0114] Except for the blank group 1, all experimental groups were given 50g of cultivation substrate per 100g of soil, i.e., 50g / 100g soil. After application, the soil and cultivation substrate were mixed evenly. The cultivation substrate was applied before sowing the rapeseed seeds.

[0115] Take 100g of soil with different cultivation substrates and place them in 9mm petri dishes. Disinfect rapeseed seeds with 0.5% sodium hypochlorite solution for 30 minutes, rinse three times with distilled water, and then evenly apply them into the petri dishes, with 50 seeds in each petri dish. Place the petri dishes in a constant temperature incubator at 20℃, with 12 hours of light and 12 hours of darkness. Water the soil daily to keep it moist and record the number of germinations.

[0116] The number of seeds germinated daily in each experimental group is shown in Table 1. The germination rate of rapeseed seeds in each experimental group 10 days after planting is shown in Table 2.

[0117] Table 1. Daily seed germination count for each experimental group

[0118]

[0119]

[0120] Table 2 Germination rate of each experimental group 10 days after rapeseed planting.

[0121] Group Germination rate (%) Blank Group 1 78 Experiment 1 Group 96 Experiment 2 group 98 Experimental Group 3 94 Control Group 1 80 Control group 2 86 Control group 3 80 Control group 4 88 Control group 5 80 Control group 6 84 7 control groups 82 8 control groups 78 9 control groups 80 10 control groups 84 11 control groups 80 12 control groups 78 13 control groups 82

[0122] As can be seen from Tables 1-2, the cultivation substrates provided in Examples 1-3 and Comparative Examples 1-13 all improved the germination rate of rapeseed seeds compared with the control group. The effects of Examples 1-3 were more significant than those of Comparative Examples 1-13.

[0123] Application Example 2: The Promoting Effect of Cultivation Substrate on Plant Growth

[0124] The cultivation substrates prepared in Examples 1-3 and Comparative Examples 1-13 were applied to a rapeseed growth experiment, and were divided into four groups: control group 1, experimental group 1, experimental group 2, experimental group 3, control group 1, control group 2, control group 3, control group 4, control group 5, control group 6, control group 7, control group 8, control group 9, control group 10, control group 11, control group 12, and control group 13. All groups used the same management model, with the following differences:

[0125] Blank group 1: No cultivation substrate added; Experimental group 1: Cultivation substrate prepared in Example 1 applied; Experimental group 2: Cultivation substrate prepared in Example 2 applied; Experimental group 3: Cultivation substrate prepared in Example 3 applied; Control group 1: Cultivation substrate prepared in Comparative Example 1 applied; Control group 2: Cultivation substrate prepared in Comparative Example 2 applied; Control group 3: Cultivation substrate prepared in Comparative Example 3 applied; Control group 4: Cultivation substrate prepared in Comparative Example 4 applied; Control group 5: Cultivation substrate prepared in Comparative Example 5 applied; Control group 6: Cultivation substrate prepared in Comparative Example 6 applied; and so on; Control group 13: Cultivation substrate prepared in Comparative Example 13 applied.

[0126] Except for the blank group 1, all experimental groups were given 50g of cultivation substrate per 100g of soil, i.e., 50g / 100g soil. After application, the soil and cultivation substrate were mixed evenly. The cultivation substrate was applied before sowing the rapeseed seeds.

[0127] 1000g of soil with different cultivation substrates was placed in flowerpots with an inner diameter of 13cm and an inner height of 12cm. Rapeseed seeds were disinfected with 0.5% sodium hypochlorite solution for 30 minutes, rinsed three times with distilled water, and then evenly distributed into the flowerpots, with 10 seeds in each flowerpot. The flowerpots were placed in a constant temperature incubator at 20℃, with 12 hours of light and 12 hours of darkness. The soil was kept moist by watering every day. The rapeseed was harvested on the 30th day, and the plant height, fresh weight, and chlorophyll content of the leaves were measured.

[0128] Table 3 shows the plant height, fresh weight, and leaf chlorophyll content of rapeseed after harvest in each experimental group.

[0129] Table 3. Plant height, fresh weight, and leaf chlorophyll content (mean) of rapeseed after harvest in each experimental group.

[0130]

[0131]

[0132] As shown in Table 3, the cultivation substrate prepared by the present invention can more significantly promote the growth of rapeseed and increase the plant height, fresh weight and chlorophyll content of leaves.

[0133] Application Example 3: Experiment on the effect of cultivation substrate on plant stress resistance, drought resistance

[0134] The cultivation substrates prepared in Examples 1-3 and Comparative Examples 1-13 were applied to a rapeseed growth experiment, and were divided into four groups: control group 1, experimental group 1, experimental group 2, experimental group 3, control group 1, control group 2, control group 3, control group 4, control group 5, control group 6, control group 7, control group 8, control group 9, control group 10, control group 11, control group 12, and control group 13. All groups used the same management model, with the following differences:

[0135] Blank group 1: No cultivation substrate added; Experimental group 1: Cultivation substrate prepared in Example 1 applied; Experimental group 2: Cultivation substrate prepared in Example 2 applied; Experimental group 3: Cultivation substrate prepared in Example 3 applied; Control group 1: Cultivation substrate prepared in Comparative Example 1 applied; Control group 2: Cultivation substrate prepared in Comparative Example 2 applied; Control group 3: Cultivation substrate prepared in Comparative Example 3 applied; Control group 4: Cultivation substrate prepared in Comparative Example 4 applied; Control group 5: Cultivation substrate prepared in Comparative Example 5 applied; Control group 6: Cultivation substrate prepared in Comparative Example 6 applied; and so on; Control group 13: Cultivation substrate prepared in Comparative Example 13 applied.

[0136] Except for the blank group 1, all experimental groups were given 50g of cultivation substrate per 100g of soil, i.e., 50g / 100g of soil. The cultivation substrate was applied before sowing the rapeseed seeds.

[0137] 1000g of soil with different cultivation substrates was placed in flowerpots with an inner diameter of 13cm and an inner height of 12cm. Rapeseed seeds were disinfected with 0.5% sodium hypochlorite solution for 30 minutes, rinsed three times with distilled water, and then evenly distributed into the flowerpots, 10 seeds per pot. The flowerpots were placed in a constant temperature incubator at 20℃, with 12 hours of light followed by 12 hours of darkness. For the drought-resistant treatment group, the soil was kept moist by watering daily until the 10th day after sowing. After all the rapeseed had germinated on the 10th day, watering was stopped, and the plants were allowed to dry naturally for two weeks before re-watering. Harvesting was carried out on the 30th day. The survival rate, plant height, and fresh weight of the rapeseed were measured.

[0138] Table 4 shows the survival rate, plant height, and fresh weight of rapeseed after harvest in the drought-resistant treatment group.

[0139] Table 4. Survival rate, plant height, and fresh weight (mean) of rapeseed after harvest in the drought-resistant treatment group.

[0140]

[0141]

[0142] As shown in Table 4, the cultivation substrate provided by the present invention can significantly improve the drought resistance of rapeseed, promote the growth of rapeseed under drought conditions, improve the survival rate of rapeseed under drought conditions, and also increase the plant height and fresh weight of rapeseed.

[0143] Application Example 4: Experiment on the effect of cultivation substrate on plant stress resistance, salt tolerance

[0144] The experimental groups and methods were the same as in Application Example 3, except that the salt-tolerant treatment group was irrigated with a 200mM NaCl aqueous solution every 3 days after sowing to keep the soil moist, and the rapeseed was harvested on the 30th day. The survival rate, plant height and fresh weight of the rapeseed were measured.

[0145] Table 5 shows the survival rate, plant height, and fresh weight of the rapeseed after harvest in the salt-tolerant treatment group.

[0146] Table 5. Survival rate, plant height, and fresh (mean) of rapeseed after harvest in the salt-tolerant treatment groups.

[0147]

[0148]

[0149] As shown in Table 5, the cultivation substrate provided by the present invention can significantly improve the salt tolerance of rapeseed, improve the physical and chemical properties of the soil, and thus promote the growth of rapeseed under high salt conditions. While improving the survival rate of rapeseed under high salt conditions, it can also increase the plant height and fresh weight of rapeseed.

[0150] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. People can obtain other embodiments based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A cultivation substrate, characterized in that, By weight, it includes: 1-7 parts of algae-bacteria symbiosis, 1-12 parts of modified illite tailings, and 1-22 parts of sheep manure; The algae-bacterial symbiosis includes Chlorella vulgaris and Streptomyces flavus; The method for preparing the algae-bacterial symbiont includes: After inoculating Chlorella and Streptomyces flavus into a culture medium and co-amplifying them, the algae-bacterium symbiosis was obtained. The Chlorella includes Chlorella FACHB-28; the Streptomyces flavus includes Streptomyces flavus with accession number CGMCC 4.6556; When inoculation is performed, the volume ratio of Chlorella algal liquid and Streptomyces microflavus liquid is (3-5):1; the density of Chlorella in the Chlorella algal liquid is 1×10 6 / mL, and the bacterial activity of Streptomyces microflavus in the Streptomyces microflavus liquid is 2×10 8 CFU / mL. The amplification culture was carried out under light for 12-14 hours per day, with a light intensity of 5000-5500 Lux, a temperature of 25-28°C, and a duration of 10-12 days. The method for preparing the modified illite tailings includes: The illite tailings were crushed, dried, and then calcined in stages to obtain the modified illite tailings. The segmented calcination includes a first calcination and a second calcination; The temperature of the first calcination is 150~250℃; the time of the first calcination is 1~3h; The second calcination temperature is 400~500℃; the second calcination time is 1.5~3h.

2. The growing medium according to claim 1, characterized in that, The drying temperature is ≤40℃.

3. A method of preparing a growing medium according to claim 1 or 2, characterised in that, Includes the following steps: The cultivation substrate is obtained by mixing algae-bacteria symbiosis, modified illite tailings and sheep manure and then fermenting the mixture.

4. The preparation method according to claim 3, characterized in that, The fermentation temperature is 25–40°C, and the time is 10–15 days.

5. The application of the cultivation substrate according to claim 1 or 2 or the cultivation substrate prepared by the preparation method according to claim 3 or 4 in any one or more of the following aspects (1) to (4): (1) Improve the soil; (2) Promotes seed germination and increases seed germination rate; (3) Improve plant stress resistance; (4) Promote plant growth.

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