Granular material prepared based on biomass leavening and mineral substances and application of granular material as culture medium

Abstract

The invention belongs to the technical field of culture substrates, and particularly relates to a granular material prepared on the basis of biomass leavening and mineral substances and application of the granular material as a culture substrate. The granular material provided by the invention comprises the following raw materials: mineral powder, a biomass fermentation product, a polysaccharide-acid compound and a binder, the polysaccharide-acid compound is composed of chitosan and potassium humate, the polysaccharide-acid compound is loaded on mineral powder by adopting a vacuum negative pressure impregnation method, and finally the granular material is prepared. The granular material is stable in structure and high in moisture and fertilizer retention capacity, has biological activity and is environmentally friendly.

Description

Technical Field

[0001] This invention belongs to the field of cultivation substrate technology, and more specifically relates to a granular material prepared based on biomass fermentation products and minerals and its use as a cultivation substrate. Background Technology

[0002] With the rapid development of modern agriculture and horticulture, the demand for efficient, environmentally friendly, and sustainable cultivation substrates is increasing. Traditional cultivation substrates often use non-renewable resources or high-cost mineral materials such as peat, vermiculite, and perlite. This not only consumes a lot of resources but also easily leads to soil compaction and ecological imbalance with long-term use. Furthermore, some substrates have poor water and fertilizer retention capacity and insufficient aeration, making it difficult to meet the needs of healthy crop root growth.

[0003] In recent years, the resource utilization of agricultural waste and organic biomass has become a research hotspot. Biomass fermentation products (such as straw, livestock manure, and kitchen waste) can be converted into stable products rich in organic matter and humic acid after anaerobic or aerobic fermentation, possessing excellent capabilities in improving soil structure and providing slow-release nutrients. However, when fermentation products are used alone as cultivation substrates, they often suffer from low mechanical strength, easy decomposition, unstable structure, and high salinity, limiting their application in large-scale planting.

[0004] On the other hand, mineral materials such as bentonite, diatomaceous earth, zeolite, and phosphate rock powder are widely used to improve the physicochemical properties of matrices due to their excellent ion exchange capacity, adsorption performance, and structural stability. However, these materials usually lack organic nutrients, and their effects are limited when used alone.

[0005] Therefore, how to scientifically combine biomass fermentation products with functional minerals and prepare them through reasonable processes into novel cultivation substrates with excellent physical structure (such as granularity and porosity), good water retention and air permeability, stable slow-release nutrient capacity, and environmentally friendly characteristics has become an urgent technical problem to be solved in the field of green agricultural materials. Currently, there is a lack of a composite granular substrate material that can simultaneously achieve resource recycling, controllable production costs, stable performance, and applicability to the cultivation of various plants. This invention is proposed against this background, aiming to provide a granular cultivation substrate based on the synergistic effect of biomass fermentation products and minerals, its preparation method, and its applications. Summary of the Invention

[0006] The purpose of this invention is to provide a granular material prepared based on biomass fermentation products and minerals and its use as a cultivation substrate, in order to solve the problems existing in the prior art.

[0007] To achieve the above objectives, the present invention provides the following solution: One of the technical solutions of this invention: provides a granular material based on biomass fermentation products and minerals, wherein the raw materials, by mass, include: 20-50 parts mineral powder, 40-70 parts biomass fermentation product, 3-10 parts polysaccharide-acid complex and 2-6 parts binder; The polysaccharide-acid complex is composed of chitosan and potassium humate.

[0008] Furthermore, the mass ratio of chitosan to potassium humate in the polysaccharide-acid complex is 1:2-2:1.

[0009] Furthermore, the binder comprises plant-derived colloids and / or modified starch.

[0010] Optionally, the plant-derived colloid includes gum arabic and / or xanthan gum.

[0011] Optionally, the modified starch includes oxidized starch and / or cross-linked starch.

[0012] Furthermore, the preparation steps of the mineral powder include: grinding the mineral to 200-400 mesh, activating it with 0.5 mol / L hydrochloric acid solution for 1-2 hours, washing it with water until neutral, and drying it at 80-100 ℃ to obtain the mineral powder.

[0013] Optionally, the mineral includes at least one of bentonite, diatomite, zeolite, and attapulgite.

[0014] Furthermore, the preparation steps of the biomass fermentation product include: mixing straw and poultry and livestock manure at a dry weight ratio of 1:1-3, adjusting the moisture content to 50-60%, and carrying out aerobic fermentation treatment at 55-70℃ for 7-14 days. The material that passes through a 10-mesh sieve is then the biomass fermentation product.

[0015] The second technical solution of the present invention provides a method for preparing the above-mentioned granular material based on biomass fermentation products and minerals, the steps of which include: The polysaccharide-acid complex was mixed with water to prepare a composite solution with a concentration of 2 wt%. The mineral powder was immersed in the composite solution using a vacuum negative pressure impregnation method, and then dried at 40-50℃ to obtain modified mineral composite powder. The modified mineral composite powder, biomass fermentation product, and binder are mixed evenly, granulated, and dried to obtain the granular material.

[0016] Furthermore, the vacuum negative pressure impregnation method uses a pressure of -0.08 MPa and a time of 10-20 min.

[0017] Furthermore, the granulation is carried out under spray wetting conditions.

[0018] Furthermore, the drying process involves circulating air drying at 40-60°C until the moisture content is no higher than 15%.

[0019] The third technical solution of the present invention provides an application of the above-mentioned granular material based on biomass fermentation products and minerals in the preparation of cultivation substrate.

[0020] The fourth technical solution of the present invention provides a cultivation substrate, the components of which include the above-mentioned granular materials based on biomass fermentation products and minerals.

[0021] The present invention discloses the following technical effects: This invention combines the synergistic effects of high specific surface area minerals, functional organic ferments, and specific functional components to construct a novel composite cultivation substrate that is structurally stable, has strong water and fertilizer retention capacity, is biologically active, and is environmentally friendly.

[0022] This invention achieves effective regulation and functional utilization of pore structure through mineral activation and polysaccharide-acid complex impregnation processes, enhancing water retention and pollutant fixation capabilities. It solves the problem of stable colonization of microorganisms in artificial substrates through a triple strategy of fermentation material carrying microbial communities, mineral framework fixation, adsorption, and binder fixation. Simultaneously, it establishes a synergistic system for slow nutrient release and supply: slow mineralization of organic matter provides long-lasting nitrogen and carbon sources, mineral ion exchange releases cations such as potassium, calcium, and magnesium, and polysaccharide-acid complex degradation releases small-molecule carbon sources to drive microbial activity, forming a three-in-one nutrient supply network of "organic-inorganic-biological". Detailed Implementation

[0023] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0024] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0025] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0026] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be readily apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0027] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0028] Unless otherwise specified, all raw materials and reagents involved in the specific embodiments of this invention are commercially available products.

[0029] Unless otherwise specified, room temperature and normal temperature in the specific embodiments of this invention refer to 20-30℃.

[0030] It should be noted that any aspects not described in detail in this invention are conventional practices in the field and are not the focus of this invention.

[0031] Unless otherwise specified, the term "parts" in the specific embodiments of this invention refers to "parts by mass".

[0032] Unless otherwise specified, the straw mentioned in the specific embodiments of the present invention refers to "corn straw" and the poultry and livestock manure refers to "cow manure".

[0033] In some specific embodiments, the present invention provides a method for preparing granular materials based on biomass fermentation products and minerals, the steps of which include: S1. Grind the minerals (at least one of bentonite, diatomite, zeolite and attapulgite) to 200-400 mesh, activate them with 0.5 mol / L hydrochloric acid solution for 1-2 hours, wash them with water until neutral, and dry them at 80-100 ℃ to obtain mineral powder. S2. Mix 3-10 parts of polysaccharide-acid complex (chitosan and potassium humate in a mass ratio of 1:2-2:1) with water to prepare a composite solution with a concentration of 2wt%. S3. Immerse 20-50 parts of mineral powder in the composite solution, perform vacuum negative pressure impregnation treatment for 10-20 minutes under -0.08MPa conditions, and then dry at 40-50℃ to obtain modified mineral composite powder. S4. Mix straw and poultry and livestock manure at a dry weight ratio of 1:1-3, adjust the moisture content to between 50-60%, control the temperature between 55-70℃ and carry out aerobic fermentation for 7-14 days. The material that passes through a 10-mesh sieve is the biomass fermentation product. S5. Mix the modified mineral composite powder obtained in step S3, 40-70 parts of biomass fermentation product and 2-6 parts of binder evenly, granulate under spray wetting conditions, and then dry with circulating air at 40-60℃ until the moisture content is not higher than 15% to obtain granular material. The binder includes plant-derived colloids and / or modified starch, the plant-derived colloids including gum arabic and / or xanthan gum, and the modified starch including oxidized starch and / or cross-linked starch.

[0034] Minerals are physically ground and chemically activated to remove impurities and increase pore permeability, resulting in mineral powders with excellent specific surface area (≥80 m²). 2 With a porosity of 2-50 nm, it possesses excellent adsorption and ion exchange capabilities, thereby improving the material's water and fertilizer retention capacity, regulating pH, and can also be used to chelate heavy metal ions (such as Cd). 2+ Pb 2+ And so on), and provide a spatial basis for the subsequent loading of materials.

[0035] The raw materials for preparing biomass fermentation products in this invention are straw and livestock and poultry manure. High-temperature aerobic fermentation is carried out under controlled temperature and humidity conditions to achieve thorough decomposition. The resulting biomass fermentation products are rich in stable humus and beneficial microbial communities (including Bacillus, Actinomyces, phosphate-solubilizing bacteria, etc.). This fermentation product not only provides a slow-release nitrogen and carbon source, but also serves as a "seed bank" for rhizosphere microbial colonization.

[0036] The polysaccharide-acid complex provided by this invention is a composite system of soluble natural polysaccharides and potassium humate. Its molecular size is smaller than that of mineral pores, and it can enter the internal pores of minerals through a vacuum impregnation process, thereby improving the water-holding capacity of minerals and slowly releasing carbon sources during degradation, supporting the growth and metabolism of beneficial microorganisms, and enhancing the stability of the rhizosphere microecology.

[0037] This invention uses plant-derived colloids or modified starch with good thermal stability as binders, which have both bonding and shaping functions as well as three-dimensional structural support functions. During granulation and drying, a network skeleton structure is formed, which significantly improves the compressive strength of the particles and the structural durability under repeated wet and dry cycles.

[0038] Example 1 The preparation steps of granular materials based on biomass fermentation products and minerals include: S1. Grind the mineral (zeolite) to 400 mesh, activate it with 0.5 mol / L hydrochloric acid solution for 1 hour, wash it with water until neutral, and dry it at 80 ℃ to obtain mineral powder. S2. Mix 10 parts of polysaccharide-acid complex (chitosan and potassium humate in a mass ratio of 1:1) with water to prepare a composite solution with a concentration of 2wt%. S3. Immerse 40 parts of mineral powder in the composite solution and perform vacuum negative pressure impregnation treatment for 10 min under -0.08 MPa conditions, followed by drying treatment at 50℃ to obtain modified mineral composite powder. S4. Mix straw and poultry manure at a dry weight ratio of 1:1, adjust the moisture content to between 50-60%, control the temperature between 55-70℃ and carry out aerobic fermentation for 14 days. The material that passes through a 10-mesh sieve is the biomass fermentation product. S5. Mix the modified mineral composite powder obtained in step S3, 60 parts of the biomass fermentation product in step S4 and 5 parts of binder (cross-linked starch) evenly, granulate under spray wetting conditions (between 3-5 mm), and then dry in circulating air at 60°C until the moisture content is not higher than 15% to obtain granular material.

[0039] Example 2 A method for preparing granular materials based on biomass fermentation products and minerals, comprising the following steps: S1. Grind the mineral (attapulgite) to 200 mesh, activate it with 0.5 mol / L hydrochloric acid solution for 2 hours, wash it with water until neutral, and dry it at 100 ℃ to obtain mineral powder. S2. Mix 3 parts of polysaccharide-acid complex (chitosan and potassium humate in a mass ratio of 2:1) with water to prepare a composite solution with a concentration of 2wt%. S3. Immerse 20 mineral powders in a composite solution and perform vacuum negative pressure impregnation treatment for 10 min under -0.08 MPa conditions, followed by drying treatment at 50℃ to obtain modified mineral composite powder. S4. Mix straw and poultry manure at a dry weight ratio of 1:1, adjust the moisture content to between 50-60%, control the temperature between 55-70℃ and carry out aerobic fermentation for 14 days. The material that passes through a 10-mesh sieve is the biomass fermentation product. S5. Mix the modified mineral composite powder obtained in step S3, 40 parts of the biomass fermentation product in step S4 and 2 parts of binder (xanthan gum) evenly, granulate under spray wetting conditions (between 3-5 mm), and then dry in circulating air at 60°C until the moisture content is not higher than 15% to obtain granular material.

[0040] Example 3 A method for preparing granular materials based on biomass fermentation products and minerals, comprising the following steps: S1. Grind the mineral (bentonite) to 200 mesh, activate it with 0.5 mol / L hydrochloric acid solution for 1 hour, wash it with water until neutral, and dry it at 80 ℃ to obtain mineral powder. S2. Mix 5 parts of polysaccharide-acid complex (chitosan and potassium humate in a mass ratio of 1:1) with water to prepare a composite solution with a concentration of 2wt%. S3. Immerse 50 parts of mineral powder in the composite solution and perform vacuum negative pressure impregnation treatment for 10 min under -0.08 MPa conditions, followed by drying treatment at 50℃ to obtain modified mineral composite powder. S4. Mix straw and poultry manure at a dry weight ratio of 1:1, adjust the moisture content to between 50-60%, control the temperature between 55-70℃ and carry out aerobic fermentation for 14 days, then crush and pass through a 10-mesh sieve to obtain biomass fermentation product. S5. Mix the modified mineral composite powder obtained in step S3, 70 parts of the biomass fermentation product in step S4 and 6 parts of binder (gum arabic) evenly, granulate under spray wetting conditions (between 3-5 mm), and then dry in circulating air at 60°C until the moisture content is not higher than 15% to obtain granular material.

[0041] Comparative Example 1 The preparation steps of particulate materials include: S1. Grind the mineral (zeolite) to 400 mesh, activate it with 0.5 mol / L hydrochloric acid solution for 1 hour, wash it with water until neutral, and dry it at 80 ℃ to obtain mineral powder. S2. Mix straw and poultry manure at a dry weight ratio of 1:1, adjust the moisture content to between 50-60%, control the temperature between 55-70℃ and carry out aerobic fermentation for 14 days. The material that passes through a 10-mesh sieve is the biomass fermentation product. S3. Mix 40 parts of mineral powder, 10 parts of polysaccharide-acid complex (chitosan and potassium humate in a mass ratio of 1:1), 60 parts of biomass fermentation product from step S2, and 5 parts of binder (cross-linked starch) evenly, granulate under spray wetting conditions (between 3-5 mm), and then dry with circulating air at 60°C until the moisture content is not higher than 15% to obtain granular material.

[0042] Test case The particulate materials prepared in Examples 1-3 and Comparative Example 1 were tested as follows (using conventional methods), and the results are shown in Table 1.

[0043] bulk density (g / cm³) 3 (1) Graduated cylinder method: Take a certain volume of particles, weigh them, and calculate their dry mass. Total porosity (%): Calculated using Archimedes' principle, based on the saturated water absorption mass and buoyancy of the particles; Water holding capacity (g water / 100g dry material): Saturated water absorption rate method, the particles are weighed after being soaked to saturation, and the water absorption is calculated; Compressive strength (N / particle): Particle strength tester, a single particle is subjected to uniform pressure until it breaks, and the peak force is recorded; Structural durability (integrity retention rate after 5 wet-dry cycles): In the wet-dry cycle experiment, the particles were repeatedly switched between dry and saturated water absorption states, and the damage was observed and recorded.

[0044] Table 1 Table 1 shows that in Examples 1-3, due to vacuum negative pressure impregnation modification, the internal pores of the minerals were functionalized, forming a richer pore structure. Therefore, the total porosity and water holding capacity were superior. In contrast, the minerals in Comparative Example 1 (unmodified) failed to effectively contribute to the pores, resulting in higher bulk density and the lowest porosity and water holding capacity. Compressive strength and structural durability are closely related to the use of binders and the uniformity of the internal structure of the particles. Examples 3 (using gum arabic), 2 (using xanthan gum), and 1 (using cross-linked starch) showed excellent performance. Comparative Example 1, due to the simple mixing of all raw materials, had a loose structure and thus the worst mechanical properties. Comparative Example 1 directly mixed the polysaccharide-humic acid complex instead of preloading it into the mineral pores. This may have resulted in it mainly acting as a surface binder during granulation and drying, making it difficult to fully utilize its functions within the mineral pores, such as enhancing water holding capacity and regulating nutrient release.

[0045] To further verify the application of the granular material prepared in this invention as a cultivation substrate in seedling cultivation, a seedling cultivation scheme with tomato as a representative crop is provided to verify the effect of the substrate. The composition of the substrate is shown in Table 2.

[0046] Table 2 Select a 50-well tray and fill each of the four substrate formulations (T1, T2, T3, CK) into the tray, gently compacting them so that the substrate surface is about 0.5 cm below the tray opening. Repeat each formulation in 30 trays.

[0047] Tomato variety: Jinpeng No. 9.

[0048] Sow one seed per hole, at a depth of about 0.5-1 cm.

[0049] After sowing, place the seeds in a greenhouse, maintaining a daytime temperature of 25-28℃ and a nighttime temperature of 15-18℃. Keep the substrate moist before emergence, and after emergence, manage water according to the principle of "watering when dry." Do not apply additional fertilizer during the entire seedling period.

[0050] After sowing, the number of seedlings for each treatment was recorded daily, and the seedling emergence rate was calculated after the seedling emergence stabilized.

[0051] When the seedlings have grown to 4-5 true leaves and are ready for transplanting (approximately 40 days after sowing), 10 seedlings are randomly selected from each treatment, and the following indicators are measured: Growth indicators: plant height, stem diameter; Root system indicators: Root system total length, total root volume, and number of root tips were analyzed using a root scanner; Seedling Strength Index: This is a comprehensive evaluation index, calculated as: (stem diameter / plant height + underground dry weight / above-ground dry weight) × total plant dry weight; the higher the seedling strength index, the better the seedling quality and the stronger the resistance.

[0052] Transplant each group of seedlings, along with the substrate, to the field. Observe regularly after transplanting, record the seedling establishment status, and the survival rate 15 days after transplanting.

[0053] The results are shown in Table 3.

[0054] Table 3 Table 3 shows that there was no significant difference in germination rate among the treatments, indicating that the granular material provided by this invention does not inhibit seed germination when used as a substrate and has basic safety. Treatments T1 and T3 were significantly superior to the CK control group in total root length and seedling vigor index, demonstrating that a good pore structure and abundant nutrients jointly promote root health and development, thereby cultivating stronger seedlings. The high survival rate of the experimental groups (especially T3) is attributed to the good structural stability of the granules. During transplanting, the roots can combine with the substrate to form a strong root ball, which is not easily broken, greatly reducing root damage and thus resulting in a high survival rate.

[0055] The above tomato seedling experiments demonstrate that the granular material of this invention, whether used alone or in combination with coconut coir, peat, etc., exhibits excellent substrate effects in tomato seedling cultivation, especially in promoting root development, cultivating strong seedlings, and improving transplant survival rate.

[0056] This further demonstrates that the granular material provided by this invention has a positive promoting effect on seedling cultivation due to its stable structure, strong water and fertilizer retention capacity, and biological activity. Minerals provide physical support, fermentation products and polysaccharide-acid complexes coordinate the supply of nutrients and water, and beneficial microorganisms promote rhizosphere health.

[0057] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0058] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A granular material based on biomass fermentation products and minerals, characterized in that, By weight, the raw materials include: 20-50 parts mineral powder, 40-70 parts biomass fermentation product, 3-10 parts polysaccharide-acid complex and 2-6 parts binder; The polysaccharide-acid complex is composed of chitosan and potassium humate.

2. The granular material as described in claim 1, characterized in that, The mass ratio of chitosan to potassium humate in the polysaccharide-acid complex is 1:2-2:1; And / or, the binder comprises plant-derived colloids and / or modified starch.

3. The granular material as described in claim 2, characterized in that, The plant-derived colloids include gum arabic and / or xanthan gum; And / or, the modified starch includes oxidized starch and / or cross-linked starch.

4. The granular material as described in claim 1, characterized in that, The preparation steps of the mineral powder include: grinding the mineral to 200-400 mesh, activating it with 0.5 mol / L hydrochloric acid solution for 1-2 hours, washing it with water until neutral, and drying it at 80-100℃ to obtain the mineral powder; the mineral includes at least one of bentonite, diatomite, zeolite and attapulgite.

5. The granular material as described in claim 1, characterized in that, The preparation steps of the biomass fermentation product include: mixing straw and poultry and livestock manure at a dry weight ratio of 1:1-3, adjusting the moisture content to 50-60%, and carrying out aerobic fermentation treatment at 55-70℃ for 7-14 days. The material that passes through a 10-mesh sieve after being crushed is the biomass fermentation product.

6. A method for preparing granular materials based on biomass fermentation products and minerals as described in any one of claims 1-5, characterized in that the steps include... include: The polysaccharide-acid complex was mixed with water to prepare a composite solution with a concentration of 2 wt%. The mineral powder was immersed in the composite solution using a vacuum negative pressure impregnation method, and then dried at 40-50℃ to obtain modified mineral composite powder. The modified mineral composite powder, biomass fermentation product, and binder are mixed evenly, granulated, and dried to obtain the granular material.

7. The preparation method according to claim 6, characterized in that, The vacuum negative pressure impregnation method uses a pressure of -0.08 MPa and a time of 10-20 min.

8. The preparation method according to claim 6, characterized in that, The granulation is performed under spray wetting conditions; And / or, the drying is performed by circulating air drying at 40-60°C until the moisture content is not higher than 15%.

9. The use of the granular material based on biomass fermentation products and minerals as described in any one of claims 1-5 in the preparation of cultivation substrates.

10. A cultivation substrate, characterized in that, The components include the granular material based on biomass fermentation products and minerals as described in any one of claims 1-5.

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