Culture medium capable of reducing content of heavy metals in soil and preparation method and application of culture medium

Abstract

The invention provides a culture medium capable of reducing soil heavy metal content and a preparation method and application thereof, and belongs to the technical field of culture mediums. The invention discloses a composite culture medium with termitomyces albuminosus residues as a core raw material, efficient resource utilization of agricultural waste is achieved, the termitomyces albuminosus residues are mainly formed by fermenting saw dust, wheat bran, cotton seed hulls, wheat straw and the like and contain rich organic matter such as cellulose, hemicellulose and lignin, and the termitomyces albuminosus residues are rich in organic matter such as calcium carbonate and calcium carbonate. The organic matters can generate various active functional groups in the decomposition process, such as hydroxyl, carboxyl, amino and the like. The functional groups can be subjected to complexation, ion exchange and other reactions with heavy metal ions, so that adsorption and immobilization of the heavy metal ions are realized. The termitomyces albuminosus residues are returned to the field for use, so that the yield, quality and soil fertility of cucumbers, muskmelons, lettuces, pakchoi, green peppers, pears and other melons, fruits and vegetables can be improved, the soil safety is improved, and the dual goals of agricultural waste resource utilization and soil pollution treatment are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of cultivation substrates, and in particular to a cultivation substrate capable of reducing the heavy metal content in soil, and a preparation method and application thereof. Background Art

[0002] As a core component of terrestrial ecosystems, soils support approximately 95% of global food production and play an irreplaceable role in carbon and nitrogen cycles, groundwater purification, and habitat maintenance. However, with the increasing use of industrial activities such as mining, smelting, and chemical processing, as well as inappropriate agricultural inputs, soils face the severe challenge of multiple pollution sources, including heavy metals and organic pollutants. This has led to increasingly severe problems, including physical structural damage, imbalanced chemical properties, and a sharp decline in biodiversity.

[0003] Heavy metal pollution in soil has become a global ecological challenge due to its hidden, long-term, and irreversible nature. Heavy metal pollutants, such as cadmium, lead, mercury, and arsenic, have half-lives in soil of decades or even centuries. Heavy metals such as lead, cadmium, mercury, and chromium are difficult to degrade, easily accumulate, and are highly toxic. When heavy metal levels in soil exceed standards, they disrupt the structure of soil microbial communities, inhibit soil enzyme activity, and reduce the soil's biological activity and self-purification capacity. Furthermore, heavy metals can be absorbed through plant roots and enter the food chain, accumulating in plants and animals, ultimately harming human health and causing various diseases. Furthermore, the acidic soil environment further exacerbates the activity and bioavailability of cadmium, leading to frequent cadmium-exceeding standards in agricultural products. This, transmitted through the food chain, poses a potential threat to human health, necessitating the urgent need for efficient soil remediation and pollution prevention and control technologies.

[0004] Therefore, reducing soil pollution has become an urgent need to safeguard ecological and environmental safety and human health. Clean soil is the foundation of sustainable agricultural development and key to maintaining ecological balance. Reducing soil pollution helps restore soil ecological functions, improves agricultural product quality, and reduces environmental pollution risks, which is of great significance to achieving the development goal of harmonious coexistence between man and nature.

[0005] Mushroom residue is the waste compost left after edible fungi cultivation. It is rich in organic matter, bacterial proteins, enzymes, and trace elements. Its comprehensive utilization can not only address environmental pollution issues but also bring significant ecological and economic benefits. As an edible fungus with high economic value, Albizia albuminosa produces a large amount of mushroom residue during its cultivation. Currently, this residue is mostly discarded or simply composted, which not only wastes resources but also has potential adverse impacts on the environment. Albizia albuminosa residue is primarily fermented from sawdust, wheat bran, cottonseed hulls, and wheat straw. It is rich in organic matter such as cellulose, hemicellulose, and lignin. These organic substances produce various active functional groups such as hydroxyl, carboxyl, and amino groups during decomposition. The rational utilization of mushroom residue can transform waste products of the edible fungi industry into valuable resources, address the pollution problem of waste accumulation, achieve resource recycling, and achieve both economic and environmental benefits.

[0006] Therefore, whether fungal residue can be used to reduce heavy metal pollution in soil is crucial to improving soil fertility and increasing crop yields. Summary of the Invention

[0007] The purpose of the present invention is to provide a cultivation matrix that can reduce the heavy metal content in the soil, as well as its preparation method and application. The crop cultivation matrix prepared from the residue of Alpinia albuminosa has the synergistic benefits of repairing heavy metal pollution, improving soil fertility and promoting crop yield, providing an integrated solution for the resource utilization of residue and green agriculture.

[0008] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions: The invention provides a cultivation matrix capable of reducing the heavy metal content in soil. The cultivation matrix comprises albuminus residue and soil.

[0009] Preferably, the addition ratio of the Alstonia albuminosa residue and soil is 2~4:1~2.

[0010] Preferably, the raw materials of the Alstonia albuminosa residue include sawdust, wheat bran, cottonseed hulls, and wheat straw.

[0011] The present invention also provides a method for preparing the above-mentioned cultivation substrate capable of reducing the heavy metal content in soil, comprising the following steps: Impurities in the residue of the Alstonia albuminosa are removed and the residue is crushed, the moisture content of the residue is adjusted, and then the residue is mixed with soil to obtain a cultivation medium.

[0012] Preferably, when adjusting the moisture content of the Albizia albuminosa residue, the moisture content is controlled to be 10-35%.

[0013] The present invention also provides an application of the above-mentioned cultivation medium capable of reducing the heavy metal content in soil in plant cultivation.

[0014] The beneficial effects of the present invention compared with the prior art are: (1) The present invention discloses a composite cultivation matrix with the residue of Alstonia albuminosa as the core raw material, which realizes the efficient resource utilization of agricultural waste. The residue is mainly fermented from sawdust, wheat bran, cottonseed hulls, wheat straw, etc., and contains rich organic matter such as cellulose, hemicellulose, lignin, etc. These organic matter will produce various active functional groups such as hydroxyl, carboxyl, amino, etc. during the decomposition process. These functional groups can react with heavy metal ions through complexation, ion exchange, etc., thereby achieving the adsorption and fixation of heavy metal ions. Returning the residue of Alstonia albuminosa to the field can improve the yield, quality and soil fertility of fruits and vegetables such as cucumbers, melons, lettuce, Chinese cabbage, green peppers, and pears, improve soil safety, and achieve the dual goals of resource utilization of agricultural waste and soil pollution control.

[0015] (2) The present invention mixes the residue of Alpinia arborescens with soil in proportion, and produces a highly stable matrix through crushing, screening, homogenization and mixing processes. The matrix is ​​rich in active ingredients such as humic acid and amino acids. Based on the synergistic effect of humic acid and amino acids, the matrix can simultaneously optimize the soil pH to 6.0-7.5, improve the aggregate structure and enhance the water and fertilizer retention capacity. At the same time, it innovatively adopts an organic chelation mechanism to passivate soil heavy metals. Through the chelation and fixation of active substances in the residue with soil cadmium ions, the migration capacity of cadmium in the soil-plant system is reduced. Field experiments show that the application of this cultivation matrix to crops such as cucumbers, tomatoes, and peppers increases yield by 16.7%-22.5%, increases soil organic matter content, and decreases cadmium content, forming a synergistic benefit of "soil improvement-pollution remediation-crop quality improvement and yield increase", providing an innovative solution for green agriculture that combines ecological safety with economic benefits. DETAILED DESCRIPTION

[0016] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0017] It should be understood that the terms described herein are intended only to describe particular embodiments and are not intended to limit the present invention. In addition, for numerical ranges herein, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Each smaller range between any intermediate value within a stated value or stated range and any other stated value or intermediate value within the stated range is also encompassed by the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded within the scope.

[0018] Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of any conflict with any incorporated document, the contents of this specification shall prevail.

[0019] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments described herein without departing from the scope or spirit of the invention. Other embodiments will be apparent to those skilled in the art from the description of the invention. The description and examples are intended to be exemplary only.

[0020] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0021] The present invention also provides a method for preparing the above-mentioned cultivation medium, comprising the following steps: Impurities in the residue of the Alstonia albuminosa are removed and the residue is crushed, the moisture content of the residue is adjusted, and then the residue is mixed with soil to obtain a cultivation medium.

[0022] Preferably, the nutritional content of the Albizia albuminosa residue is: 5-15g potassium salt, 8-25g nitrogen, 3-9g phosphorus, and 300-717g biological organic matter per kilogram of residue.

[0023] Preferably, the Alstonia albuminosa residue is prepared by fermenting a mixture of sawdust, wheat bran, cottonseed hulls and wheat straw in a mass ratio of 3:2:2:3.

[0024] Preferably, the particle size of the crushed Albizia albuminosa residue is less than 1 cm.

[0025] Preferably, the water content is less than or equal to 30%.

[0026] Preferably, the mass ratio of the Alstonia albuminosa residue to soil is 2-4:1-2.

[0027] Example 1 Example 1 of the present invention provides a method for preparing a cultivation substrate that can reduce the heavy metal content in soil, and the specific steps are as follows: (1) Take the residue made by fermenting a mixture of sawdust, wheat bran, cottonseed hulls and wheat straw in a mass ratio of 3:2:2:3 after the cultivation of Alstonia albuminosa, and remove impurities such as plastic bags and stones to ensure the purity of the residue.

[0028] (2) The collected residue of Alternaria albuminosa was crushed to a particle size of less than 1 cm for subsequent mixing. The crushed residue was then dried to control its moisture content at 30%.

[0029] (3) The preliminarily treated residue of Alternaria japonica was mixed with soil in a mass ratio of 3:1 to obtain a cultivation medium that can reduce the content of heavy metals in the soil.

[0030] Example 2 Example 2 of the present invention provides a method for preparing a cultivation substrate that can reduce the heavy metal content in soil, and the specific steps are as follows: (1) Take the residue made by fermenting a mixture of sawdust, wheat bran, cottonseed hulls and wheat straw in a mass ratio of 3:2:2:3 after the cultivation of Alstonia albuminosa, and remove impurities such as plastic bags and stones to ensure the purity of the residue.

[0031] (2) The collected residue of Alternaria albuminosa was crushed to a particle size of less than 1 cm for subsequent mixing. The crushed residue was then dried to control its moisture content to 20%.

[0032] (3) The preliminarily treated residue of Alternaria japonica was homogenized and mixed with soil in a mass ratio of 4:1 to obtain a cultivation medium that can reduce the content of heavy metals in the soil.

[0033] Example 3 Example 3 of the present invention provides a method for preparing a cultivation substrate that can reduce the heavy metal content in soil, and the specific steps are as follows: (1) Take the residue made by fermenting a mixture of sawdust, wheat bran, cottonseed hulls and wheat straw in a mass ratio of 3:2:2:3 after the cultivation of Alstonia albuminosa, and remove impurities such as plastic bags and stones to ensure the purity of the residue.

[0034] (2) The collected residue of Alternaria albuminosa was crushed to a particle size of less than 1 cm for subsequent mixing. The crushed residue was then dried to control its moisture content to 10%.

[0035] (3) The preliminarily treated residue of Alternaria japonica was mixed with soil in a mass ratio of 2:1 to obtain a cultivation medium that can reduce the content of heavy metals in the soil.

[0036] Example 4 Example 4 of the present invention provides a method for preparing a cultivation substrate that can reduce the heavy metal content in soil, and the specific steps are as follows: (1) Take the residue made by fermenting a mixture of sawdust, wheat bran, cottonseed hulls and wheat straw in a mass ratio of 3:2:2:3 after the cultivation of Alstonia albuminosa, and remove impurities such as plastic bags and stones to ensure the purity of the residue.

[0037] (2) The collected residue of Alternaria albuminosa was crushed to a particle size of less than 1 cm for subsequent mixing. The crushed residue was then dried to control its moisture content at 25%.

[0038] (3) The preliminarily treated residue of Alternaria japonica was mixed with soil in a mass ratio of 1:1 to obtain a cultivation medium that can reduce the content of heavy metals in the soil.

[0039] Test Example 1 Test Example 1 of the present invention tested the planting effect of the cultivation medium prepared in Example 1 that can reduce the heavy metal content in the soil. The specific steps are as follows: The animals were grouped according to the experimental group (the cultivation medium of Example 1), the blank control group (conventional soil), and the albuminus slag control group.

[0040] All three groups planted cucumbers, tomatoes, and peppers, and tested the physical and chemical properties of the soil and the vegetable yields. The results are shown in Tables 1 to 3.

[0041]

[0042] As shown in Table 1, the cultivation matrix prepared with the residue of Alstonia albuminosa as a soil conditioner is rich in active ingredients such as humic acid and amino acids, which can quickly improve soil nutrients. Moreover, based on the synergistic effect of humic acid and amino acids, the matrix can also simultaneously optimize the soil pH to 6.0-7.5, enhance fertilizer retention capacity, and is particularly suitable for improving acidic and barren soils, improving soil safety, and achieving the dual goals of agricultural waste resource utilization and soil pollution control.

[0043]

[0044] According to the analysis of the cadmium content records in different planting areas in Table 2, it was found that the addition of albuminus residue significantly reduced the cadmium content in the pepper and tomato soils, and also had a certain reducing effect on the cucumber soil. This shows that the addition of albuminus residue matrix not only diluted the cadmium in the soil, but also significantly reduced the effectiveness of cadmium by increasing pH, increasing organic matter and promoting microbial activity, thereby showing a lower cadmium content in the test and achieving adsorption and fixation of heavy metal ions.

[0045]

[0046] As shown in Table 3, the cadmium contents of cucumbers, tomatoes, and peppers all met national standards, with no cadmium detected in cucumbers. The yield increase was significant (16.7%-22.5%), which was directly related to the nutrient supply and soil improvement effects of the Alstonia albuminosa residue. In addition, the Alstonia albuminosa residue can synergistically reduce the bioavailability of cadmium by regulating pH, providing organic matter, and a high-potassium environment, thereby achieving a synergistic benefit of "soil improvement—pollution remediation—crop quality improvement and yield increase," providing an innovative solution for green agriculture that combines ecological safety with economic benefits.

[0047] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A cultivation medium capable of reducing the content of heavy metals in soil, characterized in that: The cultivation matrix comprises Alstonia albuminosa residue and soil.

2. The cultivation medium capable of reducing the heavy metal content in soil according to claim 1, characterized in that: The addition ratio of the described Alstonia albuminosa residue and soil is 2-4:1-2.

3. The cultivation medium capable of reducing the heavy metal content in soil according to claim 1, characterized in that: The raw materials of the albuminus slag include sawdust, wheat bran, cottonseed hulls and wheat straw.

4. A method for preparing a cultivation medium capable of reducing the heavy metal content in soil according to any one of claims 1 to 3, characterized in that: The steps include: Impurities in the residue of the Alstonia albuminosa are removed and the residue is crushed, the moisture content of the residue is adjusted, and then the residue is mixed with soil to obtain a cultivation medium.

5. The method for preparing a cultivation medium capable of reducing heavy metal content in soil according to claim 4, characterized in that: When adjusting the moisture content of the albuminus slag, the moisture content is controlled to be 10-35%.

6. Use of a cultivation substrate capable of reducing the content of heavy metals in soil according to any one of claims 1 to 3 or a cultivation substrate prepared by the method for preparing the cultivation substrate capable of reducing the content of heavy metals in soil according to any one of claims 4 to 5 in plant cultivation.

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