Functional seedling substrate based on reed whole-plant tissue pretreatment and sectional fermentation and preparation method of functional seedling substrate

Abstract

The invention discloses a functional seedling substrate based on reed whole plant tissue pretreatment and sectional fermentation and a preparation method thereof, and relates to the technical field of seedling substrates. The functional seedling culture substrate is prepared by taking reeds as a main raw material, performing crushing, grading sorting and sectional biological fermentation treatment, and then compounding with a water-retaining agent. The prepared functional seedling culture substrate has good water-retaining property, air permeability and nutrient retention capacity, the germination rate and the seedling strengthening index of seeds can be remarkably improved, the trichoderma biological substrate promotes healthy growth of seedlings, the root system is developed, the disease resistance and stress resistance of the seedlings are improved, the survival rate and growth vigor of the seedlings in acidified and salinized soil are improved, and the survival rate of the seedlings in the acidified and salinized soil is increased. High popularization and application values are realized.

Description

Technical Field

[0001] This invention relates to the field of seedling substrate technology, specifically to a functional seedling substrate based on whole-plant tissue pretreatment and segmented fermentation of reeds and its preparation method. Background Technology

[0002] With the transformation of modern agriculture from extensive to intensive and industrialized methods, the quality of seedling substrates, as the starting point of crop production, directly determines the quality of seedlings and the final yield. Peat moss, due to its excellent water retention, air permeability, and stable physicochemical properties, has long been widely used in horticultural seedling substrates. However, peat moss has a long formation cycle, and its large-scale extraction not only damages wetland ecosystems but also causes a decline in biodiversity and an increase in carbon emissions, becoming a prominent problem restricting the sustainable development of the horticultural industry. my country's peat moss resources are relatively scarce, and it currently relies mainly on imports. These imports are not only expensive (unbearable for rice and other field crops), but also cannot meet the needs of my country's agricultural production. Therefore, finding green, low-carbon, and renewable alternatives to peat moss has become a current research hotspot.

[0003] As a widely distributed and diverse emergent aquatic plant of the Poaceae family in my country, reed possesses a strong ability to purify water and conserve wetlands, and its ecological functions are unparalleled by other plants. Its high annual yield, strong renewability, and periodic harvesting not only promote reed growth and increase yield but also prevent reed residue from polluting water bodies. Reed was once not only a good raw material for papermaking but also a common fuel for farmers and a frequently used building material. However, with the closure and elimination of paper mills located in ecologically sensitive areas due to severe pollution from traditional papermaking processes, the issue of high-value utilization of reed resources has become prominent.

[0004] Reed stems contain abundant lignin, cellulose, and hemicellulose, theoretically making them an important biomass source for synthetic substrates and an ideal alternative to peat moss. However, direct utilization of reeds faces several challenges. Firstly, both reeds and leaves are rich in allelochemicals such as polyphenols and organic acids, which, when untreated, significantly inhibit seed germination and seedling root growth. Secondly, the significant differences in lignin, cellulose, and hemicellulose content between reed stems and leaves prevent microorganisms from simultaneously degrading multiple components during traditional composting. Furthermore, the degradation rates, physicochemical properties, and structures of stems and leaf sheaths differ considerably, representing specific requirements for an ideal substrate. Therefore, developing a method for preparing seedling substrates through segmented fermentation of the entire reed plant is of significant theoretical and practical importance. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide a functional seedling substrate based on reed grading and segmented fermentation, and its preparation method.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A method for preparing a functional seedling substrate based on whole-plant tissue pretreatment and segmented fermentation of reeds includes the following steps: (1) Raw material pretreatment: Take the dried whole plant of reeds, crush it, and sieve it through wind separation. It is divided into two components, A and B. Component A mainly includes the lignified part of the stem, and component B mainly includes the leaves, leaf sheaths and inflorescences. (2) Segmented fermentation: Component A treatment: a. Static high-temperature acidification fermentation: Adjust the carbon-nitrogen ratio to 25:1-30:1 with amino acids, add water to adjust the material moisture to 50%-60%, then add cellulase and build up a pile for high-temperature fermentation; b. Mesophilic aerobic fermentation and functionalization: After the temperature of the pile in step a drops to 30-40℃, amino acids are added to acidify and nutrientize the material, and Trichoderma liquid fermentation mycelium is inoculated for aerobic fermentation. Component B treatment: a. Static high-temperature acidification fermentation: Adjust the carbon-nitrogen ratio to 25:1-30:1 with amino acids, add water to adjust the material moisture to 50%-60%, then add cellulase and build up a pile for high-temperature acidification fermentation; b. High-temperature aerobic fermentation: After the temperature of the pile from step a drops to 30-40℃, inoculate with compound microbial fermentation agents to carry out aerobic fermentation; (3) Substrate compounding: The fermented components A, B and water-retaining agent are compounded to obtain the seedling substrate.

[0007] In step (3), the water-retaining agent is prepared as follows: A1: N,N'-methylenebisacrylamide reacts with 1,6-hexanediamine to form a hyperbranched product. A2: Hyperbranched products react with gluconolactone to form a water-retaining agent.

[0008] In step A1, the molar ratio of N,N'-methylenebisacrylamide to 1,6-hexanediamine is 1:(1.4-1.5).

[0009] In step A2, the molar ratio of the hyperbranched product to gluconolactone is 1:(8.05-8.1).

[0010] In step (2), the amino acid is a liquid amino acid.

[0011] In step (2), the aerobic fermentation cycle of component A is 15-20 days, and the aerobic fermentation cycle of component B is 10-15 days.

[0012] In step (2), in the A component treatment, the amount of cellulase added is 0.15%-0.25% of the dry weight of component A; the amount of Trichoderma liquid fermentation mycelium inoculated is 0.5%-1.0% of the dry weight of component A; in the B component treatment, the amount of cellulase added is 0.15%-0.25% of the dry weight of component B; and the amount of compound microbial fermentation agent inoculated is 0.1%-0.3% of the dry weight of component B.

[0013] In step (2), the temperature for aerobic fermentation of component A with Trichoderma is 25-40℃, and the temperature for aerobic fermentation of component B is 60-65℃.

[0014] In step (3), the volume ratio of component A to component B is 1:(3-3.5); the mass-volume ratio of water-retaining agent to component A is (0.3-0.65):1.

[0015] Furthermore, a functional seedling substrate based on whole-plant tissue pretreatment and segmented fermentation of reeds was prepared using the above method.

[0016] Due to the adoption of the above technical solutions, the beneficial effects of the present invention include: 1. This invention employs a static high-temperature fermentation process. By precisely controlling the pile size and covering management, it ensures that the core temperature of the material can effectively rise to above 60°C and be maintained for a sufficient time, thoroughly killing pathogens, weed seeds, and insect eggs. Simultaneously, the acidic environment formed in the subsequent facultative / anaerobic stage effectively promotes the degradation of allelochemicals, fundamentally eliminating the phytotoxicity of the raw materials and ensuring the safety of seedling cultivation.

[0017] 2. The raw materials are graded by physical sieving and fermented differently according to their characteristics (aeration of component A and water retention of component B), and finally compounded as needed; this achieves precise design and flexible control of the physical properties of the substrate, which can meet the personalized needs of different crop seedlings and overcome the defects of uneven product properties in traditional processes.

[0018] 3. This invention is not a simple composting process, but rather involves the targeted inoculation of Trichoderma into component A, which has a high degree of lignification, during the mesophilic aerobic stage. This functional microbial agent can rapidly colonize into a dominant microbial community in the acidic environment established in the early stage. It not only efficiently decomposes lignocellulose and improves the material structure, but its metabolic activities can also secrete growth-promoting substances (such as auxins) and antibacterial substances (such as chitinase), enabling the substrate itself to have the ability to continuously promote growth and inhibit soil-borne diseases, thereby reducing the dependence on chemical pesticides during the seedling stage.

[0019] 4. Adding amino acids at the beginning of fermentation to adjust the carbon-nitrogen ratio provides fast-acting nutrition for fermenting microorganisms and accelerates the fermentation process. On the other hand, it directly integrates organic nutrients into the fermentation process, transforming them into organic forms that are more easily absorbed by plants. This significantly improves the initial nutrient level of the substrate, upgrading it from a simple "support medium" to a "nutrient carrier," laying a solid foundation for cultivating strong seedlings.

[0020] 5. The functional seedling substrate prepared by this invention exhibits high levels of performance in terms of plant germination rate, plant height, stem diameter, aboveground fresh weight, total plant dry weight, and seedling vigor index. The hyperbranched water-retaining agent molecules introduced into this substrate contain abundant hydrophilic functional groups and a three-dimensional network structure, enabling the formation of a stable water absorption and slow-release system within the substrate. This effectively enhances the substrate's water retention, aeration, and nutrient retention capacity, providing a continuous and balanced supply of water and nutrients to seedlings, thereby promoting root growth and aboveground biomass accumulation, and improving the overall growth quality of seedlings. Detailed Implementation

[0021] The following description, in conjunction with specific embodiments, provides further details, but the present invention is not limited to these embodiments.

[0022] Example 1: Preparation of water-retaining agent: S1: Under nitrogen protection and in an ice bath, add 300 ml of anhydrous methanol and 0.1 mol of N,N′-methylenebisacrylamide to the reactor, then add 1.2 ml of... 1,8-Diazabicycloundec-7-ene was stirred for 5 min, and then 60 mL of anhydrous methanol solution containing 0.06 mol of 1,6-hexanediamine was slowly added dropwise over 30 min. After the addition was complete, the reaction was stirred for another 30 min in an ice bath. The temperature was then raised to 30°C and stirred for 4 h. After that, the temperature was raised to 40°C, and then 80 mL of anhydrous methanol solution containing 0.08 mol of 1,6-hexanediamine was slowly added dropwise over 30 min. After the addition was complete, the reaction was stirred for another 12 h at 40°C. After the reaction was complete, the mixture was rotary evaporated at 45°C for 2 h, and then slowly added to 500 mL of anhydrous diethyl ether. The mixture was stirred, and a precipitate was formed. The precipitate was filtered, washed three times with cold diethyl ether (100 mL each time), and dried under vacuum at 50°C for 24 h to obtain the hyperbranched product. The reaction equation is shown below.

[0023] S2: Add 1000 ml DMSO (dimethyl sulfoxide), 0.1 mol hyperbranched product, and 0.805 mol gluconolactone to the reactor, stir, heat to 40 °C, react for 10 h, then cool to room temperature, distill under reduced pressure at 70 °C for 1.5 h, and dry under vacuum at 50 °C for 12 h to obtain the water-retaining agent; the reaction equation is shown below:

[0024] Example 2: Preparation of water-retaining agent: S1: Under nitrogen protection and in an ice bath, 300 ml of anhydrous methanol and 0.1 mol of N,N′-methylenebisacrylamide were added to the reactor, followed by 1.2 ml of 1,8-diazabicycloundec-7-ene. The mixture was stirred for 5 min, and then 60 ml of anhydrous methanol solution containing 0.062 mol of 1,6-hexanediamine was slowly added dropwise over 30 min. After the addition was complete, the mixture was stirred in an ice bath for another 30 min. The temperature was then raised to 30°C and stirred for 4 h. The temperature was then raised to 40°C, and 80 ml of anhydrous methanol solution containing 0.082 mol of 1,6-hexanediamine was slowly added dropwise over 30 min. After the addition was complete, the mixture was stirred at 40°C for another 12 h. After the reaction was completed, the mixture was rotary evaporated at 45°C for 2 h. Then, the mixture was slowly added to 500 ml of anhydrous diethyl ether and stirred. The precipitate was collected, filtered, and washed three times with cold diethyl ether (100 ml each time). The precipitate was dried under vacuum at 50°C for 24 h to obtain the hyperbranched product. S2: Add 1000 ml DMSO, 0.1 mol hyperbranched product and 0.808 mol gluconolactone to the reactor, stir, heat to 45 °C, react for 10 h, cool to room temperature, distill under reduced pressure at 70 °C for 1.5 h, and dry under vacuum at 50 °C for 12 h to obtain the water-retaining agent.

[0025] Example 3: Preparation of water-retaining agent: S1: Under nitrogen protection and in an ice bath, 300 ml of anhydrous methanol and 0.1 mol of N,N′-methylenebisacrylamide were added to the reactor, followed by 1.2 ml of 1,8-diazabicycloundec-7-ene. The mixture was stirred for 5 min, and then 60 ml of anhydrous methanol solution containing 0.065 mol of 1,6-hexanediamine was slowly added dropwise over 30 min. After the addition was complete, the mixture was stirred in an ice bath for another 30 min. The temperature was then raised to 30°C and stirred for 4 h. After that, the temperature was raised to 40°C, and 80 ml of anhydrous methanol solution containing 0.085 mol of 1,6-hexanediamine was slowly added dropwise over 30 min. After the addition was complete, the mixture was stirred at 40°C for another 12 h. After the reaction was completed, the mixture was rotary evaporated at 45°C for 2 h. Then, the mixture was slowly added to 500 ml of anhydrous diethyl ether and stirred. The precipitate was collected, filtered, and washed three times with cold diethyl ether (100 ml each time). The precipitate was dried under vacuum at 50°C for 24 h to obtain the hyperbranched product. S2: Add 1000 ml DMSO, 0.1 mol hyperbranched product and 0.81 mol gluconolactone to the reactor, stir, heat to 50 °C, react for 10 h, cool to room temperature, distill under reduced pressure at 70 °C for 1.5 h, and dry under vacuum at 50 °C for 12 h to obtain the water-retaining agent.

[0026] Example 4: Preparation of functional seedling substrate: (1) Raw material pretreatment: Take 1000 kg of dried reeds, crush them with a pulverizer, and then classify them through a multi-layer screen air classifier to obtain component A, which is mainly composed of the lignified part of the stem, and component B, which is mainly composed of the leaves, leaf sheaths and inflorescence.

[0027] (2) Segmented fermentation: Component A treatment: a. Static high-temperature harmless fermentation: 27 kg of liquid amino acids were used to adjust the carbon-nitrogen ratio of 600 kg of component A from 82:1 to 25:1. Water was sprayed to adjust the moisture content of the material to 50%. Then, 0.9 kg of cellulase was added, and the adjusted component A was built into an independent pile (the pile dimensions are: 2.2 meters wide at the bottom, 1.6 meters high, and 4 meters long, in a trapezoidal shape). After the pile was built, it was immediately covered with a 0.5 mm thick perforated PE breathable membrane, and the sides were pressed tightly with sandbags. A 15 cm gap was left at the bottom for ventilation. Fermentation was then carried out. On the 4th day after the pile was built, the core temperature of the pile rose to 60℃, and the high temperature above 55℃ was maintained for 7 days. On the 32nd day after the pile was built, the pile temperature naturally dropped to 39℃, and the pH value of the material was measured to be 5.5, forming an acidic environment. b. Mesophilic aerobic functional fermentation: After the temperature of the above-mentioned pile naturally drops to 30℃, 18kg of amino acids are added to acidify and nutrientize the material. Then, the pile is turned over, and 3kg of Trichoderma liquid fermentation mycelium is inoculated into component A. After inoculation, the pile is turned over to mix it evenly and aerobic fermentation is carried out. During this stage, the pile temperature is controlled at 40℃, and the fermentation time is 15 days, during which the pile is turned over twice. After the fermentation is completed, the material is dark brown, with a loose structure, and white mycelium can be seen on the surface of the stem fragments. It has no odor but has an earthy mold smell.

[0028] Component B treatment: a. Static high-temperature harmless fermentation: 8 kg of liquid amino acids were used to adjust the carbon-nitrogen ratio of 400 kg of component B from 35:1 to 25:1. Water was sprayed to adjust the moisture content of the material to 50%. Then, 0.6 kg of cellulase was added, and the adjusted component B was built into an independent pile (the pile dimensions are: 2.2 meters wide at the bottom, 1.6 meters high, and 4 meters long, in a trapezoidal shape). After the pile was built, it was immediately covered with a 0.5 mm thick perforated PE breathable membrane, and the sides were pressed tightly with sandbags. A 15 cm gap was left at the bottom for ventilation. Fermentation was then carried out. On the 4th day after the pile was built, the core temperature of the pile rose to 60℃, and the high temperature above 55℃ was maintained for 7 days. On the 32nd day after the pile was built, the pile temperature naturally dropped to 39℃, and the pH value of the material was measured to be 5.5, forming an acidic environment. b. Mesophilic aerobic functional fermentation: After the temperature of the above-mentioned pile naturally drops to 30℃, the pile is turned over, and 0.4kg of compound microbial fermentation agent is inoculated into component B. After inoculation, the pile is turned over to make it evenly mixed and aerobic fermentation is carried out. During this stage, the pile temperature is controlled at 65℃, and the fermentation time is 10 days, during which the pile is turned over twice. After the fermentation is completed, the material is dark brown, loose in structure, odorless, and has a musty earthy smell.

[0029] (3) Substrate preparation: Take 0.40m of fermented component A. 3 Component B 1.2m 3 0.12 kg of water-retaining agent (prepared in Example 1) was mixed and stirred at 200 rpm for 20 min to obtain a functional seedling substrate with a total porosity of 70% and an air-permeable porosity to water-holding porosity ratio of 1:1.2.

[0030] Example 5: Preparation of functional seedling substrate: (1) Raw material pretreatment: Take 1000 kg of dried reeds, crush them with a pulverizer, and then classify them through a multi-layer screen air classifier to obtain component A, which is mainly composed of the lignified part of the stem, and component B, which is mainly composed of the leaves, leaf sheaths and inflorescence.

[0031] (2) Segmented fermentation: a. Static high-temperature harmless fermentation: 23 kg of liquid amino acids were used to adjust the carbon-nitrogen ratio of 600 kg of component A from 82:1 to 28:1. Water was sprayed to adjust the moisture content of both materials to 55%. Then, 1.2 kg of cellulase was added, and the adjusted component A was built into an independent pile (the pile dimensions are: 2.2 meters wide at the bottom, 1.6 meters high, and 4 meters long, in a trapezoidal shape). After the pile was built, it was immediately covered with a 0.5 mm thick perforated PE breathable membrane, and the sides were pressed tightly with sandbags. A 15 cm gap was left at the bottom for ventilation. Fermentation was then carried out. On the 4th day after the pile was built, the core temperature of the pile rose to 65℃, and the high temperature above 55℃ was maintained for 8 days. On the 32nd day after the pile was built, the pile temperature naturally dropped to 39℃, and the pH value of the material was measured to be 6.0, forming an acidic environment. b. Mesophilic aerobic functional fermentation: After the temperature of the above-mentioned pile naturally drops to 35℃, 15kg of amino acids are added to acidify and nutrientize the material. Then, the pile is turned over, and 4.8kg of Trichoderma liquid fermentation mycelium is inoculated into component A. After inoculation, the pile is turned over to mix it evenly and aerobic fermentation is carried out. During this stage, the pile temperature is controlled at 30℃, and the fermentation time is 18 days, during which the pile is turned over twice. After the fermentation is completed, the material is dark brown, with a loose structure, and white mycelium can be seen on the surface of the stem fragments. It has no odor but has an earthy mold smell.

[0032] Component B treatment: a. Static high-temperature harmless fermentation: 5 kg of liquid amino acids were used to adjust the carbon-nitrogen ratio of 400 kg of component B from 35:1 to 28:1. Water was sprayed to adjust the moisture content of the material to 55%. Then, 0.8 kg of cellulase was added, and the adjusted component B was built into an independent pile (the pile dimensions were: 2.2 meters wide at the bottom, 1.6 meters high, and 4 meters long, in a trapezoidal shape). After the pile was built, it was immediately covered with a 0.5 mm thick perforated PE breathable membrane, and the sides were pressed tightly with sandbags, leaving a 15 cm gap at the bottom for ventilation. Fermentation was then carried out. On the 4th day after the pile was built, the core temperature of the pile rose to 60℃, and the high temperature above 55℃ was maintained for 7 days. On the 32nd day after the pile was built, the pile temperature naturally dropped to 39℃, and the pH value of the material was measured to be 5.5, forming an acidic environment. b. Mesophilic aerobic functional fermentation: After the temperature of the above-mentioned pile naturally drops to 30℃, the pile is turned over, and 0.8kg of compound microbial fermentation agent is inoculated into component B. After inoculation, the pile is turned over to make it evenly mixed and aerobic fermentation is carried out. During this stage, the pile temperature is controlled at 62℃, and the fermentation time is 12 days, during which the pile is turned over twice. After the fermentation is completed, the material is dark brown, loose in structure, odorless, and has a musty earthy smell.

[0033] (3) Substrate preparation: Take 0.40m of fermented component A. 3 Component B 1.28m 3 It was mixed with 0.2 kg of water-retaining agent (prepared in Example 2), stirred at 200 rpm for 20 min to obtain a functional seedling substrate with a total porosity of 75% and an air-permeable porosity to water-holding porosity ratio of 1:1.3.

[0034] Example 6: Preparation of functional seedling substrate: (1) Raw material pretreatment: Take 1000 kg of dried reeds, crush them with a pulverizer, and then classify them through a multi-layer screen air classifier to obtain component A, which is mainly composed of the lignified part of the stem, and component B, which is mainly composed of the leaves, leaf sheaths and inflorescence.

[0035] (2) Segmented fermentation: a. Static high-temperature harmless fermentation: 20 kg of liquid amino acids were used to adjust the carbon-nitrogen ratio of 600 kg of component A from 82:1 to 30:1. Water was sprayed to adjust the moisture content of both materials to 60%. Then, 1.5 kg of cellulase was added. The adjusted components A and B were built into separate piles (pile dimensions: 2.2 m wide at the bottom, 1.6 m high, 4 m long, trapezoidal). After building the piles, they were immediately covered with a 0.5 mm thick perforated PE breathable membrane, and the sides were sealed with sandbags. A 15 cm gap was left at the bottom for ventilation. Fermentation was then carried out. On the 4th day after building the piles, the core temperature of the piles rose to 68℃ and remained above 55℃ for 10 days. On the 32nd day after building the piles, the pile temperature naturally dropped to 39℃, and the pH value of the material was measured to be 6.5, forming an acidic environment. b. Mesophilic aerobic functional fermentation: After the temperature of the above-mentioned pile naturally drops to 40℃, 13kg of amino acids are added to acidify and nutrientize the material. Then, the pile is turned over, and 6kg of Trichoderma liquid fermentation mycelium is inoculated into component A. After inoculation, the pile is turned over to mix it evenly and aerobic fermentation is carried out. During this stage, the pile temperature is controlled at 25℃, and the fermentation time is 20 days, during which the pile is turned over twice. After the fermentation is completed, the material is dark brown, with a loose structure. White mycelium can be seen on the surface of the stem fragments. It has no odor but has an earthy mold smell.

[0036] Component B treatment: a. Static high-temperature harmless fermentation: 3.5 kg of liquid amino acids were used to adjust the carbon-nitrogen ratio of 400 kg of component B from 35:1 to 30:1. Water was sprayed to adjust the moisture content of the material to 60%. Then, 1.0 kg of cellulase was added, and the adjusted component B was built into an independent pile (the pile dimensions are: 2.2 m wide at the bottom, 1.6 m high, and 4 m long, in a trapezoidal shape). After the pile was built, it was immediately covered with a 0.5 mm thick perforated PE breathable membrane, and the sides were pressed tightly with sandbags. A 15 cm gap was left at the bottom for ventilation. Fermentation was then carried out. On the 4th day after the pile was built, the core temperature of the pile rose to 60℃, and the high temperature above 55℃ was maintained for 7 days. On the 32nd day after the pile was built, the pile temperature naturally dropped to 39℃, and the pH value of the material was measured to be 5.5, forming an acidic environment. b. Mesophilic aerobic functional fermentation: After the temperature of the above-mentioned pile naturally drops to 30℃, the pile is turned over, and 1.2kg of compound microbial fermentation agent is inoculated into component B. After inoculation, the pile is turned over to make it evenly mixed and aerobic fermentation is carried out. During this stage, the pile temperature is controlled at 60℃, and the fermentation time is 15 days, during which the pile is turned over twice. After the fermentation is completed, the material is dark brown, loose in structure, odorless, and has a musty earthy smell.

[0037] (3) Substrate preparation: Take 0.40m of fermented component A. 3 Component B 1.40m 3It was compounded with 0.26 kg of water-retaining agent (prepared in Example 3), stirred at 200 rpm for 20 min to obtain a functional seedling substrate with a total porosity of 78% and an air-permeable porosity to water-retaining porosity ratio of 1:1.5.

[0038] Comparative Example 1 The composition and preparation method of the functional seedling substrate raw materials are basically the same as those in Example 5. The difference is that Trichoderma is not inoculated during the preparation process of step (2).

[0039] Comparative Example 2 The composition and preparation method of the functional seedling substrate raw materials are basically the same as those in Example 5, except that the water-retaining agent is replaced with an equal weight of water-retaining agent prepared by the following method: The preparation method of the water-retaining agent is basically the same as that in Example 2, except that 1,6-hexanediamine in step S1 is replaced with an equimolar amount of ethylenediamine.

[0040] Comparative Example 3 The composition and preparation method of the functional seedling substrate raw materials are basically the same as those in Example 5, except that the water-retaining agent is replaced with an equal weight of water-retaining agent prepared by the following method: The preparation method of the water-retaining agent is basically the same as that in Example 2, except that N,N'-methylenebisacrylamide in step S1 is replaced with an equimolar amount of 1,6-hexanediol diacrylate.

[0041] Comparative Example 4 The composition and preparation method of the functional seedling substrate raw materials are basically the same as those in Example 5, except that the water-retaining agent is replaced with an equal weight of water-retaining agent prepared by the following method: The preparation method of the water-retaining agent is basically the same as that in Example 2, except that gluconolactone in step S2 is replaced with an equimolar amount of 1,4-butyrolactone.

[0042] Comparative Example 5 The composition and preparation method of the functional seedling substrate raw materials are basically the same as those in Example 5, except that the water-retaining agent is replaced with an equal weight of water-retaining agent prepared by the following method: S1: Under nitrogen protection and in an ice bath, add 200 ml of anhydrous methanol and 0.1 mol N,N′-methylenebisacrylamide to the reactor, then add 1.2 ml of 1,8-diazabicycloundec-7-ene. Stir for 5 min, then slowly add 60 ml of anhydrous methanol solution containing 0.062 mol 1,6-hexanediamine dropwise over 30 min. After the addition is complete, continue stirring in an ice bath for 30 min, then raise the temperature to 30°C and stir for 4 h. Then raise the temperature to 40°C and slowly add 80 ml of anhydrous methanol solution containing 0.082 mol 1,6-hexanediamine dropwise over 30 min. After the addition is complete, continue stirring at 40°C for 12 h. At 40°C, slowly add 120 ml of anhydrous methanol solution containing 0.122 mol 1,6-hexanediamine dropwise over 45 min, then add 0.37 ml of the solution as a supplement. After the addition of 1,8-diazabicycloundec-7-ene was complete, the mixture was stirred at 40°C for 18 hours. After the reaction was completed, the mixture was rotary evaporated at 45°C for 2 hours. Then, it was slowly added dropwise to 500 ml of anhydrous diethyl ether and stirred. The precipitate was precipitated, filtered, and washed three times with cold diethyl ether (100 ml each time). The product was dried under vacuum at 50°C for 24 hours to obtain the third-generation hyperbranched product. S2: Add 1000 ml DMSO, 0.1 mol of third-generation hyperbranched product and 0.805 mol of gluconolactone to the reactor, stir, heat to 45 °C, react for 10 h, cool to room temperature, distill under reduced pressure at 80 °C for 2 h, and dry under vacuum at 50 °C for 12 h to obtain the water-retaining agent.

[0043] The specific parameters for grading using the multi-layer screen airflow classifier used in this embodiment and comparative example are as follows: (1) Air classification equipment and parameters: A multi-layer screen air classifier is adopted. The internal dimensions of the air classification chamber are length × width × height = 1200mm × 600mm × 800mm. The upper screen aperture is 1.2cm and the lower screen aperture is 0.4cm. The airflow velocity is 3.5m / s and the feeding speed is 180kg / h. Air classification is carried out under normal temperature (25±5℃) conditions.

[0044] (2) Material characteristics: The core basis for air separation is the difference in density and suspension velocity between components A and B. The specific parameters are: Component A (lignified stems) density 0.45-0.61 g / cm³ 3 Suspension velocity 3.5-5.0 m / s; B component (leaf, leaf sheath, inflorescence) density 0.28-0.35 g / cm³ 3 The suspension speed is 2.5-3.0 m / s.

[0045] The effective viable count of the compound microbial fermentation agent used in the embodiments and comparative examples of this application is 2 × 10⁻⁶. 9CFU / g, of which Bacillus subtilis accounted for 40% of the live bacteria, Bacillus amyloliquefaciens accounted for 25% of the live bacteria, Pseudomonas aeruginosa accounted for 15% of the live bacteria, Saccharomyces cerevisiae accounted for 10% of the live bacteria, and Actinomycetes accounted for 10% of the live bacteria.

[0046] The preparation method of Trichoderma liquid fermentation mycelium used in the embodiments and comparative examples of this application is as follows: (1) Preparation of Trichoderma seed culture: Preparation of solid culture medium: Cut 200g of potatoes into pieces, boil them in water for 30 minutes, take the filtrate, add 20g of glucose and 15g of agar, and make up to 1L with pure water. After sterilization, pour into plates.

[0047] Preparation of liquid culture medium: Cut 2000g of potatoes into pieces, boil them in water, filter them, add 180g of glucose to the filtrate, and make up to 10L with pure water. Dispense the mixture into shake flasks and sterilize them.

[0048] Transfer culture: Use an inoculation loop to pick up a small amount of Trichoderma colonies and inoculate them into solid culture medium. Incubate at 28°C in a biochemical incubator. After the Trichoderma colonies have covered the culture medium, transfer them to Trichoderma liquid culture medium and incubate at 28°C and 170 rpm for 72 hours before use.

[0049] (2) Propagation of Trichoderma strains in fermentation tanks: Preparation of liquid culture medium for fermentation tank: 150 kg potatoes, 15 kg sucrose, 5 kg corn flour, 5 kg ammonium sulfate, 0.5 kg magnesium sulfate, 1 kg potassium dihydrogen phosphate, 5 L edible oil, add water to make up to 1000 L, then sterilize and set aside; take the prepared Trichoderma seed liquid and inoculate it into the fermentation tank at an inoculation rate of 1 wt%, and after culturing for 72 h, Trichoderma liquid fermentation mycelium is obtained; fermentation parameters of the fermentation tank: 30℃, tank pressure 1 kg, aeration rate 85 cubic meters / hour, dissolved oxygen 35%, stirring 80 rpm.

[0050] The Trichoderma used was Trichoderma harzianum, model number NJAU 4742.

[0051] The liquid amino acids used in the embodiments and comparative examples of this application are AAA01L type liquid amino acid fertilizers with a total amino acid content of 30% and pH=5.0±0.5, produced by Suzhou Dora Ecological Agriculture Technology Co., Ltd.; the cellulase is industrial grade solid cellulase (100,000 u / g, CAS number 9012-54-8), produced by Shandong Longda Bioengineering Co., Ltd.

[0052] The functional seedling substrates prepared according to the embodiments of this application and the comparative examples were used to conduct seedling experiments, and the results are shown in Table 1.

[0053] Seedling trials and sample measurements: To verify the substrate performance, seedling trials were conducted using the substrates prepared in the examples and comparative examples of this application. Three replicates were set up for each substrate, with one 50-well seedling tray per group and one tomato seed sown in each well. All treatments were managed under the same temperature, light, water, and fertilizer conditions in the same greenhouse (25±2℃ / 18±2℃ day / night temperature, 16h light). Watering was carried out every 3 days using a metered watering can to ensure that each 50-well seedling tray received 25mL of irrigation each time. Germination rate was recorded on the 7th day after sowing. On the 30th day after sowing, 10 seedlings were randomly selected (30 seedlings / treatment) to measure plant height, stem diameter, above-ground fresh weight, and total dry weight, and the seedling vigor index was calculated.

[0054] The methods for measuring growth indicators are as follows: (1) Germination rate determination: Germination is defined as "the cotyledons are clearly visible and have a normal morphology" on the 7th day after sowing; the germination rate is calculated using the following formula:

[0055] (2) Plant height: Measured from the substrate surface to the top of the main stem with a graduated ruler, accurate to 0.1 cm.

[0056] (3) Stem diameter: Measure the diameter of the main stem with a vernier caliper at a distance of 1 cm from the substrate surface, accurate to 0.01 mm.

[0057] (4) Fresh weight above ground: Cut off the above-ground parts (excluding roots), weigh them with an electronic balance, accurate to 0.01g. Before weighing, lightly brush off the soil adhering to the surface with a paper towel and weigh quickly to reduce moisture evaporation.

[0058] (5) Dry weight of whole plant: Place the whole plant in a sample bag and mark it. First, dry it in a drying oven at 70℃ until constant weight. Take it out, cool it to room temperature, weigh it in a desiccator, and record the dry weight, accurate to 0.001g.

[0059] (6) Seedling Strength Index: Calculated using the following formula:

[0060] Table 1 Performance Indicators of Functional Seedling Substrates

[0061] As can be seen from Table 1, the functional seedling substrates prepared in Examples 4-6 of this application all exhibited high levels in terms of growth indicators such as germination rate, plant height, stem diameter, aboveground fresh weight, total plant dry weight, and seedling vigor index.

[0062] The water-retaining agent prepared in this invention possesses a hyperbranched three-dimensional network structure and incorporates a large number of hydrophilic functional groups (-OH, -CONH-). The three-dimensional hyperbranched structure of the water-retaining agent contains a large number of hydroxyl groups. When the substrate moisture decreases, the internal hydrogen bond network rearranges, allowing water to be released gradually, thereby achieving dynamic regulation of root humidity. This ensures a stable water supply for seedlings during germination and early growth stages, significantly improving germination and seedling survival rates. The introduced polyhydroxy structure enhances the hydrophilicity and interfacial compatibility of the water-retaining agent, enabling it to form a dynamically reversible binding network with water through hydrogen bonds. When the roots secrete organic acids or undergo local ionic changes, the stability of the hydrogen bond network is regulated, promoting the release of adsorbed water and continuously providing a suitable moist environment for the roots, enhancing root vitality and nutrient absorption capacity. Simultaneously, the polyhydroxy structure enhances compatibility with fermented organic matter from reeds, promoting the colonization and symbiosis of beneficial microorganisms in the rhizosphere. The amide bond in the water-retaining agent can interact with Ca... 2+ Mg 2+ Nutrient ions form coordination bonds, improving the matrix's ability to retain and slowly release nutrients; at the same time, these polar groups can also form hydrogen bonds with the hydroxyl groups of cellulose, hemicellulose and lignin in the reed matrix, enhancing the matrix's structural stability and aggregation.

[0063] In summary, this water-retaining agent, through its unique hyperbranched three-dimensional network structure and the synergistic effect of multiple functional groups, achieves synergistic regulation of water and nutrients in the seedling substrate, significantly improving the water retention and air permeability of the substrate, and resulting in significant improvements in indicators such as germination rate, plant height, stem diameter, fresh weight, dry weight, and seedling vigor index.

[0064] In Comparative Example 2, the prepared water-retaining agent exhibited higher linearity and flexibility in its molecular structure. The longer carbon chain made it difficult for the amide groups inside the water-retaining agent to form a stable hydrogen bond network, weakening the intermolecular forces and reducing the network cross-linking density, thereby weakening the three-dimensional network structure and water absorption and retention capacity of the system. In the seedling substrate, this structure resulted in decreased water retention and water holding stability, rapid collapse of the substrate pore structure, and uneven aeration, which restricted root development and ultimately reduced indicators such as germination rate, plant height, and seedling vigor index.

[0065] In Comparative Example 3, the 1,4-butyrolactone ring-opening introduces only a single hydroxyl group, lacking the multi-hydroxyl sites provided by gluconolactone, resulting in a significant reduction in the surface polarity of the water-retaining agent. This structure weakens both the hydrogen bonding between the molecule and water molecules and the interaction with multi-hydroxyl substances such as matrix cellulose and lignin, thus significantly reducing the hydrophilicity and interfacial binding capacity of the water-retaining agent. Consequently, both the substrate nutrient retention and water regulation performance are reduced, ultimately affecting the growth quality of seedlings.

[0066] Physicochemical property determination of the substrate: 1 kg of the seedling substrate prepared in Examples 4-6 and Comparative Example 1 was accurately weighed and placed in a dry and clean conical flask. 5 L of distilled water was measured using a graduated cylinder and poured into the conical flask containing the substrate sample. The conical flask was sealed and placed in a shaker, shaken at 150 r / min for 30 min. After shaking, the mixture was filtered, and the supernatant was collected to measure the EC value. The test results are shown in Table 2.

[0067] Table 2 Physicochemical Properties of Functional Seedling Substrates

[0068] Table 2 shows that the EC values ​​of the substrates of this invention are all within the optimal range for seedling cultivation. The slightly acidic environment is conducive to nutrient absorption and the activity of functional microorganisms. The moderate EC value proves that through the addition of amino acids and fermentation transformation, the substrate has become a safe "nutrient carrier," providing a superior chemical environment for seedling growth. The EC value of the substrate in Comparative Example 1 (uninoculated) is too low, indicating incomplete fermentation, insufficient nutrient transformation, and an unsuitable chemical environment, directly leading to its worst seedling performance. The physicochemical properties of the substrates demonstrate that this invention, while achieving harmlessness, successfully constructs a chemical microenvironment superior to that of the uninoculated treatment, which is one of the intrinsic reasons for its significant growth-promoting effect.

[0069] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. However, any modifications, alterations, and variations made by those skilled in the art without departing from the scope of the present invention based on the disclosed technical content are equivalent embodiments of the present invention. Furthermore, any modifications, alterations, and variations made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the present invention.

Claims

1. A method for preparing a functional seedling substrate based on whole-plant tissue pretreatment and segmented fermentation of reed, characterized in that, Includes the following steps: (1) Raw material pretreatment: Take the dried whole plant of reeds, crush it, and sieve it through wind separation. It is divided into two components, A and B. Component A mainly includes the lignified part of the stem, and component B mainly includes the leaves, leaf sheaths and inflorescences. (2) Segmented fermentation: Component A treatment: a. Static high-temperature acidification fermentation: Adjust the carbon-nitrogen ratio to 25:1-30:1 with amino acids, add water to adjust the material moisture to 50%-60%, then add cellulase and build up a pile for high-temperature fermentation; b. Mesophilic aerobic fermentation and functionalization: After the temperature of the pile in step a drops to 30-40℃, amino acids are added to acidify and nutrientize the material, and Trichoderma liquid fermentation mycelium is inoculated for aerobic fermentation. Component B treatment: a. Static high-temperature acidification fermentation: Adjust the carbon-nitrogen ratio to 25:1-30:1 with amino acids, add water to adjust the material moisture to 50%-60%, then add cellulase and build up a pile for high-temperature acidification fermentation; b. High-temperature aerobic fermentation: After the temperature of the pile from step a drops to 30-40℃, inoculate with compound microbial fermentation agents to carry out aerobic fermentation; (3) Substrate compounding: The fermented components A, B and water-retaining agent are compounded to obtain the seedling substrate.

2. The functional seedling substrate based on whole-plant tissue pretreatment and segmented fermentation of reed and its preparation method as described in claim 1, characterized in that, In step (3), the water-retaining agent is prepared as follows: A1: N,N'-methylenebisacrylamide reacts with 1,6-hexanediamine to form a hyperbranched product. A2: Hyperbranched products react with gluconolactone to form a water-retaining agent.

3. The functional seedling substrate based on whole-plant tissue pretreatment and segmented fermentation of reeds and its preparation method according to claim 2, characterized in that, In step A1, the molar ratio of N,N'-methylenebisacrylamide to 1,6-hexanediamine is 1:(1.4-1.5).

4. The functional seedling substrate based on whole-plant tissue pretreatment and segmented fermentation of reeds and its preparation method according to claim 2, characterized in that, In step A2, the molar ratio of the hyperbranched product to gluconolactone is 1:(8.05-8.1).

5. The functional seedling substrate based on whole-plant tissue pretreatment and segmented fermentation of reeds and its preparation method according to claim 1, characterized in that, In step (2), the amino acid is a liquid amino acid.

6. The functional seedling substrate based on whole-plant tissue pretreatment and segmented fermentation of reeds and its preparation method according to claim 1, characterized in that, In step (2), the aerobic fermentation cycle of component A is 15-20 days, and the aerobic fermentation cycle of component B is 10-15 days.

7. The functional seedling substrate based on reed grading and segmented fermentation and its preparation method according to claim 1, characterized in that, In step (2), in the A component treatment, the amount of cellulase added is 0.15%-0.25% of the dry weight of component A; the amount of Trichoderma liquid fermentation mycelium inoculated is 0.5%-1.0% of the dry weight of component A; in the B component treatment, the amount of cellulase added is 0.15%-0.25% of the dry weight of component B; and the amount of compound microbial fermentation agent inoculated is 0.1%-0.3% of the dry weight of component B.

8. The functional seedling substrate based on whole-plant tissue pretreatment and segmented fermentation of reeds and its preparation method according to claim 1, characterized in that, In step (2), the temperature for aerobic fermentation of component A with Trichoderma is 25-40℃, and the temperature for aerobic fermentation of component B is 60-65℃.

9. The functional seedling substrate based on whole-plant tissue pretreatment and segmented fermentation of reeds and its preparation method according to claim 1, characterized in that, In step (3), the volume ratio of component A to component B is 1:(3-3.5); the mass-volume ratio of water-retaining agent to component A is (0.3-0.65):

1.

10. A functional seedling substrate based on whole-plant tissue pretreatment and segmented fermentation of reed, prepared by the method described in any one of claims 1-9.

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