Multifunctional soil conditioner for improving saline-alkali soil as well as preparation method and application of multifunctional soil conditioner

Abstract

The invention relates to the technical field of fertilizers, discloses a multifunctional soil conditioner for improving saline-alkali soil as well as a preparation method and application of the multifunctional soil conditioner, and aims at solving the problem that a traditional soil conditioner is single in function. The invention provides a comprehensive soil improvement scheme capable of simultaneously improving soil fertility, structure and microbial environment and supplementing trace elements. The multifunctional soil conditioner for improving the saline-alkali soil has remarkable effects in the aspects of improving soil quality, promoting plant growth and increasing crop yield.

Description

Technical Field

[0001] The invention relates to the technical field of fertilizers, and in particular to a multifunctional soil conditioner for improving saline-alkali land, and a preparation method and application thereof. Background Art

[0002] With the continuous development of agricultural production and changes in the soil environment, the nutrient level and microbial environment of the soil are constantly under pressure. Especially in some areas with poor land, the essential nutrients in the soil are gradually lost, resulting in poor crop growth, increased diseases and reduced yields. In order to improve soil fertility and promote the healthy growth of crops, the development and application of efficient soil conditioners has become an important direction in agricultural research.

[0003] Soil conditioners usually contain organic matter, inorganic matter and probiotics, which improve the soil's physical, chemical and biological properties, thereby increasing its water retention, aeration, fertility and microbial activity. In recent years, natural materials such as biochar, humic acid and probiotics have been widely used in soil improvement and have been valued for their good environmental adaptability and soil remediation effects.

[0004] However, traditional soil conditioners often focus on a single function, such as simply improving soil fertility or improving soil structure, and lack a comprehensive formula. Therefore, there is an urgent need for a multifunctional soil conditioner that can simultaneously solve problems such as insufficient soil fertility, poor soil structure, and low microbial activity to adapt to different soil conditions and crop growth needs. Summary of the invention

[0005] In view of this, the present invention proposes a multifunctional soil conditioner for improving saline-alkali land and a preparation method and application thereof, aiming to solve the problems existing in the current technology.

[0006] The present invention provides a method for preparing a multifunctional soil conditioner for improving saline-alkali land, comprising:

[0007] The biochar, diatomaceous earth, probiotics and chelated calcium magnesium fertilizer are mixed and fermented, and after the fermentation is completed, they are dried and crushed to obtain the multifunctional soil conditioner for improving saline-alkali land;

[0008] The preparation method of the chelated calcium-magnesium fertilizer comprises: mixing and dissolving a calcium source and a magnesium source to obtain a calcium-magnesium solution, adding a chelating agent to the calcium-magnesium solution, heating and stirring to obtain a calcium-magnesium chelate, and adding a plant extract to the calcium-magnesium chelate to obtain the chelated calcium-magnesium fertilizer.

[0009] Preferably, the weight ratio of the biochar, diatomaceous earth, probiotics and chelated calcium magnesium fertilizer is 5-8:2-4:1-2:3-7.

[0010] Preferably, the method for preparing biochar comprises:

[0011] Biomass organic matter, seaweed powder and trace elements are mixed and carbonized to obtain primary charcoal; and humic acid is used to modify the primary charcoal to obtain the biochar.

[0012] Preferably, the primary carbon is modified by humic acid to obtain the biochar, comprising:

[0013] The primary charcoal and humic acid are mixed and stirred at 20-30° C., and the biochar is obtained after natural cooling;

[0014] Wherein, the added amount of the humic acid is 5%-10% of the mass of the primary carbon.

[0015] Preferably, the preparation method of humic acid comprises:

[0016] Wetting the plant waste and mixing it with microorganisms for fermentation, and then obtaining a humic acid solution by soaking and filtering; and drying the humic acid solution to obtain the humic acid;

[0017] The mixed fermentation conditions are 25-35°C and 15-30 days; the microorganisms include yeast and lactic acid bacteria.

[0018] Preferably, the probiotics include Bacillus subtilis, Bacillus licheniformis, rhizobia, lactic acid bacteria and yeast.

[0019] Preferably, the calcium source is lime powder and gypsum;

[0020] And / or, the magnesium source is magnesium sulfate.

[0021] And / or, the chelating agent is EDTA;

[0022] And / or, the plant extract is a tomato extract.

[0023] Preferably, the plant extract is a tomato extract.

[0024] The present invention also provides a multifunctional soil conditioner for improving saline-alkali land, which is prepared according to the preparation method of the multifunctional soil conditioner for improving saline-alkali land.

[0025] The present invention also proposes an application of the multifunctional soil conditioner for improving saline-alkali land, wherein the application comprises at least one of the following:

[0026] A1) Application of the multifunctional soil conditioner for improving saline-alkali land in preparing plant fertilizer;

[0027] A2) Application of the multifunctional soil conditioner for improving saline-alkali land in improving soil properties;

[0028] A3) Application of the multifunctional soil conditioner for improving saline-alkali land in promoting plant growth.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] Improve soil fertility: Through the synergistic effect of biochar, humic acid and chelated calcium-magnesium fertilizer, the organic matter content of the soil is effectively increased and the nutrient supply capacity of the soil is improved. Biochar can improve the water retention and permeability of the soil, humic acid can promote the transformation of minerals and organic matter in the soil, and calcium-magnesium fertilizer provides the key mineral elements required by plants, which improves the fertility of the soil as a whole.

[0031] Improve soil microbial environment: Probiotics in the soil, such as Bacillus subtilis and lactic acid bacteria, increase the number of beneficial microorganisms, inhibit the growth of harmful pathogens, improve the soil microbial community structure, and enhance the biological activity of the soil. This not only helps to improve the health of the soil, but also improves the disease resistance of crops and promotes the development and growth of plant roots.

[0032] Supplement trace elements: By adding trace elements (such as zinc, iron, and copper) in a reasonable ratio, the mineral content in the soil can be improved to make up for the trace element needs of plants during their growth. Trace elements can promote photosynthesis, metabolism, and disease resistance of plants, prevent nutrient deficiency, and improve crop yield and quality.

[0033] Improve crop disease resistance and growth vitality: The synergistic effect of probiotics and trace elements helps plants enhance their resistance to pathogens and reduce the occurrence of diseases. At the same time, trace elements (such as zinc and iron) are essential for plant growth and development, and can promote plant root growth, chlorophyll synthesis and stress resistance, and improve the overall health of crops.

[0034] Environmental friendliness: The soil conditioner of the present invention mainly uses natural materials (such as biochar, seaweed powder, plant waste, etc.) as raw materials, and has good environmental friendliness. The preparation process avoids the use of harmful chemicals, meets the requirements of sustainable development, and can effectively reduce soil pollution and agricultural non-point source pollution.

[0035] Enhance soil structure and water retention capacity: Biochar improves the physical properties of the soil through its porous structure, increases soil permeability and water retention capacity, reduces water evaporation and loss, especially in arid areas, helps improve soil water use efficiency, and supports crop growth under adverse climatic conditions.

[0036] In summary, the soil conditioner of the present invention provides a multifunctional and comprehensive soil improvement solution by rationally mixing multiple beneficial ingredients, combining biochar, humic acid, probiotics, trace elements and chelated calcium and magnesium fertilizers, etc. The soil conditioner can not only improve soil fertility and structure, but also regulate the soil microbial environment, supplement the trace elements required by plants, and improve the growth performance and disease resistance of crops, and has good application prospects. DETAILED DESCRIPTION

[0037] The exemplary embodiments of the present disclosure will be described in more detail below. Although the exemplary embodiments of the present disclosure are shown below, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to be able to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below in conjunction with the embodiments.

[0038] The present invention provides an innovative soil conditioner formulation and preparation method, comprising:

[0039] 1. Humic acid

[0040] 1. Formulation

[0041] Main raw materials: plant waste (straw and leaves in a weight ratio of 2-3:1);

[0042] Auxiliary ingredients: yeast and lactic acid bacteria (0.1-0.3% of the total weight of plant waste);

[0043] Other additives: Mineral powder (calcium and magnesium in a weight ratio of 1:1, with a total weight of 2-3% of the total weight of plant waste).

[0044] 2. Preparation method

[0045] Raw material pretreatment: Cut the plant waste into 5-10cm pieces, pre-wet it, and add water to promote fermentation.

[0046] Fermentation process: Add appropriate amount of yeast and lactic acid bacteria to the fermentation tank to accelerate the production of humic acid. Maintain good fermentation conditions by controlling temperature (25-35℃) and humidity.

[0047] Humic acid extraction: The fermentation cycle is usually 15-30 days, with regular stirring. After fermentation is complete, the humic acid solution is extracted by soaking and filtering.

[0048] Drying treatment: The extracted humic acid solution is spray-dried or freeze-dried to obtain powdered humic acid.

[0049] Preparation and storage: Mix humic acid powder and mineral powder evenly to obtain humic acid, and store it in a sealed container.

[0050] 2. Biochar

[0051] 1. Formulation

[0052] Raw materials: straw, wood chips, bamboo chips (weight ratio 5-7:2-4:0.5-2);

[0053] Auxiliary materials: seaweed powder (3-5% of the total weight of raw materials), trace elements (0.2-0.5% of the total weight of raw materials and seaweed powder, including zinc sulfate, iron sulfate and copper chloride in a weight ratio of 2-3: 3-4: 0.5-0.7);

[0054] Additives: Humic acid (5-8% of the total weight of raw materials and auxiliary materials).

[0055] 2. Preparation method

[0056] Raw material preparation: Cut straw, wood chips and bamboo chips into small pieces of 5-10 cm and mix them with bamboo chips.

[0057] Add auxiliary materials: According to the needs of the target soil, add seaweed powder and trace elements and stir evenly. Seaweed powder is rich in natural minerals, and trace elements have an auxiliary effect on supplementing plant nutrients in the soil.

[0058] High temperature carbonization: The mixed raw materials are placed in a high temperature carbonization furnace and subjected to high temperature carbonization at a temperature of 600-800°C. The process lasts for about 6-8 hours to ensure complete carbonization and the formation of stable biochar.

[0059] Surface modification: Add 5%-10% humic acid to the biochar mass to modify the surface of the carbonized biochar to enhance its adsorption capacity and water retention capacity. The modification temperature is 20-30℃, and light stirring is used to ensure that the humic acid is evenly attached.

[0060] Cooling and crushing: After the prepared biochar is naturally cooled to room temperature, it is crushed and screened into 2-5mm.

[0061] 3. Chelated calcium magnesium fertilizer

[0062] 1. Formulation

[0063] Calcium source: lime powder and gypsum (weight ratio is 2:0.5-1);

[0064] Magnesium source: magnesium sulfate (20%-30% of the total weight of the calcium source);

[0065] Chelating agent: EDTA (ethylenediaminetetraacetic acid, 0.5%-2% of the total weight of the calcium source and the magnesium source);

[0066] Synergist: Plant extract (tomato extract, 0.5%-1% of the total weight of chelated calcium and magnesium fertilizer). Extraction method of tomato extract: Cut tomatoes into small pieces, add them into water, and use an ultrasonic processor to subject them to ultrasonic waves with a wavelength frequency of 25±2kHz to promote cell rupture and release of active ingredients. The extract is filtered and concentrated to obtain a tomato extract, which is then spray-dried to obtain a powdered tomato extract.

[0067] 2. Preparation method

[0068] Dissolution of calcium and magnesium sources: Dissolve lime powder, gypsum and magnesium sulfate in water to prepare calcium and magnesium solution.

[0069] Chelation reaction: Add EDTA to the calcium-magnesium solution, and after heating and stirring, the calcium-magnesium ions and the chelating agent are fully combined to form a stable calcium-magnesium chelate.

[0070] Synergistic treatment: Add plant extracts to calcium-magnesium chelates to obtain chelated calcium-magnesium fertilizers. The addition of plant extracts enhances the absorption efficiency and activity of the fertilizer and reduces fertilizer loss.

[0071] Drying and crushing: The obtained chelated calcium magnesium fertilizer is treated by spray drying to obtain granular fertilizer.

[0072] Packaging and storage: Crush and screen the dried chelated calcium magnesium fertilizer, and then seal and store it.

[0073] Types of Probiotics

[0074] When preparing soil conditioners, the selection of probiotics is crucial to improving the soil microbial environment, including:

[0075] Bacillus subtilis: helps decompose organic matter, promotes the growth of plant roots, and enhances disease resistance.

[0076] Bacillus licheniformis: can promote the degradation of organic fertilizers and provide the nutrients needed by the soil.

[0077] Rhizobium spp.: helps fix nitrogen sources in the atmosphere and increase the nitrogen content in the soil.

[0078] Lactic acid bacteria (Lactobacillus spp.): help inhibit the growth of harmful pathogens and improve the structure of soil microbial communities.

[0079] Yeast (Saccharomyces cerevisiae): Helps break down organic matter and improves soil structure.

[0080] The added amount of probiotics is 0.5% of the total formula weight, and the weight ratio of Bacillus subtilis, Bacillus licheniformis, rhizobium, lactic acid bacteria and yeast is 3-4:2-3:1-1.5:1-1.5:0.5-1.

[0081] 5. Overall preparation process of soil conditioner

[0082] 1. Raw material mixing

[0083] Mix biochar, diatomaceous earth, probiotics and chelated calcium magnesium fertilizer in a weight ratio of 30-40:20-30:0.5:10-20. Biochar increases soil permeability and water retention capacity, humic acid improves soil fertility, diatomaceous earth enhances soil structure, probiotics improve microbial environment, and chelated calcium magnesium fertilizer provides plants with the necessary minerals.

[0084] 2. High temperature fermentation

[0085] The mixture is placed in a fermentation tank and the soil conditioner is activated using high temperature fermentation technology. During the fermentation process, the temperature is maintained between 55-70°C and the humidity is controlled at 60-80%. The fermentation cycle is 10-15 days, during which the soil is regularly turned over to ensure uniform fermentation.

[0086] 3. Drying and crushing

[0087] After fermentation, the soil conditioner is dried naturally or at low temperature to remove excess water. The dried material is crushed into appropriate particle size for better mixing with the soil.

[0088] 4. Packaging and storage

[0089] The final prepared soil conditioner is packaged and stored in a sealed manner to avoid moisture and pollution to ensure its activity and efficacy.

[0090] Through this innovative formula and method, the soil conditioner can provide a comprehensive soil improvement effect, increase soil fertility, improve soil structure, and enhance soil microbial activity, which helps to improve crop yield and quality. The technical solution of the present invention is specifically described below through specific embodiments.

[0091] Example 1

[0092] 1. Humic acid

[0093] 1. Formulation

[0094] Main raw materials: plant waste (wheat straw and mulberry leaves in a weight ratio of 3:1);

[0095] Auxiliary ingredients: yeast and lactic acid bacteria (0.2% of the total weight of plant waste);

[0096] Other additives: Mineral powder (calcium and magnesium in a weight ratio of 1:1, with a total weight of 2% of the total weight of plant waste).

[0097] 2. Preparation method

[0098] Raw material pretreatment: Cut the plant waste into 5-10cm pieces, pre-wet it, and add water to promote fermentation.

[0099] Fermentation process: Add appropriate amount of yeast and lactic acid bacteria to the fermentation tank to accelerate the production of humic acid. Maintain good fermentation conditions by controlling temperature (28±2℃) and humidity.

[0100] Humic acid extraction: The fermentation period is 20 days with regular stirring. After fermentation is complete, the humic acid solution is extracted by soaking and filtering.

[0101] Drying treatment: The extracted humic acid solution is spray-dried or freeze-dried to obtain powdered humic acid.

[0102] Preparation and storage: Mix humic acid powder and mineral powder evenly to obtain humic acid, and store it in a sealed container.

[0103] 2. Biochar

[0104] 1. Formulation

[0105] Raw materials: straw, wood chips, bamboo chips (weight ratio 6:3:0.5);

[0106] Auxiliary materials: seaweed powder (4% of the total weight of raw materials), trace elements (0.3% of the total weight of raw materials and seaweed powder, including zinc sulfate, iron sulfate and copper chloride in a weight ratio of 3:3:0.5);

[0107] Additives: Humic acid (7% of the total weight of raw materials and auxiliary materials).

[0108] 2. Preparation method

[0109] Raw material preparation: Cut the organic matter such as straw, wood chips and bamboo chips into small pieces of 5-10 cm and mix them with bamboo chips.

[0110] Add auxiliary materials: According to the needs of the target soil, add seaweed powder and trace elements and stir evenly. Seaweed powder is rich in natural minerals, and trace elements have an auxiliary effect on supplementing plant nutrients in the soil.

[0111] High temperature carbonization: The mixed raw materials are placed in a high temperature carbonization furnace and subjected to high temperature carbonization at a temperature of 700±20℃. The process lasts for about 7 hours to ensure complete carbonization and the formation of stable biochar.

[0112] Surface modification: Add 8% humic acid to the biochar mass to modify the surface of the carbonized biochar to enhance its adsorption capacity and water retention capacity. The modification temperature is 25±2℃, and light stirring is performed to ensure that the humic acid is evenly attached.

[0113] Cooling and crushing: After the prepared biochar is naturally cooled to room temperature, it is crushed and screened into 2-5mm.

[0114] 3. Chelated calcium magnesium fertilizer

[0115] 1. Formulation

[0116] Calcium source: lime powder and gypsum (weight ratio is 2:0.5);

[0117] Magnesium source: magnesium sulfate (20% of the total weight of calcium source);

[0118] Chelating agent: EDTA (ethylenediaminetetraacetic acid, 0.5% of the total weight of the calcium source and the magnesium source);

[0119] Synergist: Plant extract (tomato extract, 0.7% of the total weight of chelated calcium and magnesium fertilizer). Extraction method of tomato extract: Cut tomatoes into small pieces, add them into water, and use an ultrasonic processor to subject them to ultrasonic waves with a wavelength frequency of 25±2kHz to promote cell rupture and release of active ingredients. The extract is filtered and concentrated to obtain a tomato extract, which is then spray-dried to obtain a powdered tomato extract.

[0120] 2. Preparation method

[0121] Dissolution of calcium and magnesium sources: Dissolve lime powder, gypsum and magnesium sulfate in water to prepare calcium and magnesium solution.

[0122] Chelation reaction: Add EDTA to the calcium-magnesium solution, and after heating and stirring, the calcium-magnesium ions and the chelating agent are fully combined to form a stable calcium-magnesium chelate.

[0123] Synergistic treatment: Add plant extracts to calcium-magnesium chelates to obtain chelated calcium-magnesium fertilizers. The addition of plant extracts enhances the absorption efficiency and activity of the fertilizer and reduces fertilizer loss.

[0124] Drying and crushing: The obtained chelated calcium magnesium fertilizer is treated by spray drying to obtain granular fertilizer.

[0125] Packaging and storage: Crush and screen the dried chelated calcium magnesium fertilizer, and then seal and store it.

[0126] Types of Probiotics

[0127] When preparing soil conditioners, the selection of probiotics is crucial to improving the soil microbial environment, including:

[0128] Bacillus subtilis: helps decompose organic matter, promotes the growth of plant roots, and enhances disease resistance.

[0129] Bacillus licheniformis: can promote the degradation of organic fertilizers and provide the nutrients needed by the soil.

[0130] Rhizobium spp.: helps fix nitrogen sources in the atmosphere and increase the nitrogen content in the soil.

[0131] Lactic acid bacteria (Lactobacillus spp.): help inhibit the growth of harmful pathogens and improve the structure of soil microbial communities.

[0132] Yeast (Saccharomyces cerevisiae): Helps break down organic matter and improves soil structure.

[0133] The added amount of probiotics is 0.5% of the total formula weight, and the weight ratio of Bacillus subtilis, Bacillus licheniformis, rhizobium, lactic acid bacteria and yeast is 3:2:1:1:0.5.

[0134] 5. Overall preparation process of soil conditioner

[0135] 1. Raw material mixing

[0136] Mix biochar, diatomaceous earth, probiotics and chelated calcium magnesium fertilizer in a weight ratio of 7:3:1:5. Biochar increases soil permeability and water retention capacity, humic acid improves soil fertility, diatomaceous earth enhances soil structure, probiotics improve microbial environment, and chelated calcium magnesium fertilizer provides plants with the necessary minerals.

[0137] 2. High temperature fermentation

[0138] The mixture is placed in a fermentation tank and the soil conditioner is activated using high temperature fermentation technology. During the fermentation process, the temperature is maintained between 55-70°C and the humidity is controlled at 60-80%. The fermentation cycle is 10-15 days, during which the soil is regularly turned over to ensure uniform fermentation.

[0139] 3. Drying and crushing

[0140] After fermentation, the soil conditioner is dried naturally or at low temperature to remove excess water. The dried material is crushed into appropriate particle size for better mixing with the soil.

[0141] 4. Packaging and storage

[0142] The final prepared soil conditioner is packaged and stored in a sealed manner to avoid moisture and pollution to ensure its activity and efficacy.

[0143] Through this innovative formula and method, the soil conditioner can provide a comprehensive soil improvement effect, increase soil fertility, improve soil structure, and enhance soil microbial activity, which helps to improve crop yield and quality. The technical solution of the present invention is specifically described below through specific examples. It should be noted that in the actual implementation of the following examples, the middle value of the range value in the above method is taken.

[0144] Example 2

[0145] The implementation method is the same as that of Example 1, except that:

[0146] Raw material mixing: Biochar, diatomaceous earth, probiotics and chelated calcium magnesium fertilizer are accurately mixed in a weight ratio of 8:4:2:3. Probiotics use mixed fermentation culture to ensure their activity and better soil adaptability.

[0147] High temperature fermentation: Ferment the mixture at 43±2℃ for 15 days and keep the humidity at around 60% to promote the growth and decomposition of microorganisms.

[0148] Drying and crushing: After fermentation, low-temperature drying is carried out until the moisture content is less than 15%, and then the material is crushed into 1-3mm particles.

[0149] Packaging and storage: Store in a ventilated and dry environment to ensure the biological activity of probiotics.

[0150] Example 3

[0151] The implementation method is the same as that of Example 1, except that:

[0152] Raw material mixing: biochar, humic acid, diatomaceous earth, probiotics and chelated calcium magnesium fertilizer are mixed in a weight ratio of 5:2:1:7. Probiotics use mixed fermentation culture solution.

[0153] Fermentation treatment: Fermentation is carried out for 10 days at 48±2℃, and the humidity is maintained at about 50% to promote the active reaction of humic acid and microorganisms.

[0154] Drying and crushing: After fermentation, the material needs to be dried at low temperature to keep the moisture content below 20%, and then crushed into 2-5mm particles.

[0155] Packaging and storage: Sealed packaging, stored in a dry and cool place to ensure the long-term effectiveness of the soil conditioner.

[0156] Comparative Example 1

[0157] The preparation method is the same as that of Example 1, except that humic acid is not added.

[0158] Comparative Example 2

[0159] The preparation method is the same as that of Example 1, except that no probiotics are added.

[0160] Comparative Example 3

[0161] The preparation method is the same as that of Example 1, the only difference being that no chelated calcium-magnesium fertilizer is added.

[0162] Test Example 1

[0163] The soil conditioners prepared in Examples 1-3 and Comparative Examples 1-3 were subjected to performance tests.

[0164] 1. Quality inspection method

[0165] 1. Soil pH measurement

[0166] Instruments and equipment: pH meter, electrode.

[0167] Procedure: Take a certain amount of treated soil sample, about 50g. Add the soil sample to 100ml of deionized water and stir evenly. Leave it for 30 minutes to allow the soil and water to fully react. Use a pH meter to measure the pH value of the solution, perform three repeated measurements, and take the average value.

[0168] 2. Electrical conductivity (EC) determination

[0169] Instruments and equipment: conductivity meter.

[0170] Procedure: Take 50g soil sample, add 100ml deionized water, stir thoroughly, and leave for 20 minutes to ensure that the salt is completely dissolved. Use a conductivity meter to measure the conductivity (mS / cm) of the solution, and perform three repeated measurements to take the average value.

[0171] 3. Determination of organic matter content

[0172] Instruments and equipment: acid-base titration equipment.

[0173] Procedure: Take 20g soil sample and air dry it to remove moisture. React the soil sample with 0.5N K2Cr2O7 solution for 1 hour at a temperature of about 30°C. Determine the amount of K2Cr2O7 remaining using titration to calculate the organic matter content in the soil.

[0174] 4. Determination of nitrogen, phosphorus and potassium content

[0175] Instruments: Spectrophotometer.

[0176] Procedure: Take 5g of soil sample, soak it with distilled water and filter to obtain filtrate. Use nitrogen, phosphorus and potassium determination reagents to determine the nitrogen, phosphorus and potassium content in the filtrate. Repeat the test three times and take the average value.

[0177] 2. Performance Test Method

[0178] 1. Crop growth performance test

[0179] Soil: Soils with different treatments (Examples 1-3 and Comparative Examples 1-3) were used.

[0180] Crops: Choose fast growing crops (wheat).

[0181] Planting containers: Use planting pots or seedling trays of uniform size.

[0182] Process: Fill the treated soil evenly into the cultivation containers, with the weight of soil in each container being 500g. Plant 5 crop seeds (wheat) in each container, ensuring that the seeds are at the same depth of about 1-2cm. Water every day to keep the soil moist, and control the temperature at 25℃±2℃. Measure the growth height, number of leaves and plant weight of the crop every 5 days. The plant weight is measured on the 30th day, and the crop is cut, weighed and recorded. The experimental period is 30 days, and the growth conditions at different time points are recorded.

[0183] 2. Soil structural improvement test

[0184] Instruments and equipment: soil porosity measuring instrument, water permeability meter.

[0185] Porosity determination: Take 20 g of treated soil, use the density bottle method to measure the bulk density of the soil, and calculate the soil porosity. Porosity (%) = (1-soil particle size density / total soil bulk density) × 100%.

[0186] A certain amount of soil (about 200g) was filled into the water permeability meter to measure the rate at which water passes through the soil. The permeability of soil water per unit time (cm / h) was calculated. The changes in water permeability of each experimental group and control group were recorded.

[0187] 3. Microbial activity test

[0188] Take soil samples with different treatments, each sample is about 100g.

[0189] Air-dry the soil and sieve to remove large particles. Divide the treated soil sample into small portions, mix each with 1L of sterile saline, stir thoroughly, and let stand for 1 hour. Add an appropriate amount of culture medium (agar medium) to the soil suspension and culture it at a suitable temperature (about 28°C). Calculate the total colony count of microorganisms in the soil (expressed in cfu / g) by the colony count method after culture. Record the number of microorganisms, repeat the test three times, and take the average value.

[0190] 3. Test Results

[0191] The test results are shown in Table 1.

[0192] Table 1

[0193] Experimental group / control group Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Soil pH 7.3 7.4 7.2 7.7 7.6 7.8 Electrical conductivity (EC) (mS / cm) 4.5 4.6 4.4 5.2 5.1 5.5 Organic matter content 5.3 5.5 5.1 4.3 4.1 4.0 Nitrogen content (mg / kg) 250 270 240 210 200 190 Phosphorus content (mg / kg) 45 48 43 40 38 35 Potassium content (mg / kg) 180 190 170 160 155 150 Crop height (cm) 78 81 75 62 58 55 Number of crop leaves 10 12 9 8 7 6 Plant weight (g) 15 18 14 13 12 11 Total number of microorganisms (cfu / g) <![CDATA[1.2×10 6 ]]> <![CDATA[1.3×10 6 ]]> <![CDATA[1.1×10 6 ]]> <![CDATA[9.8×10 5 ]]> <![CDATA[8.5×10 5 ]]> <![CDATA[7.5×10 5 ]]> Porosity 40 42 41 38 37 36 Water permeability (cm / h) 5 5.3 5.1 4.8 4.7 4.5

[0194] As can be seen from Table 1, the improvement of soil pH, conductivity, organic matter and nitrogen, phosphorus and potassium content are all better than those of Comparative Examples 1-3. In particular, the soil conditioners of Examples 1-3 significantly increased the growth height, leaf number and plant weight of crops, while increasing the total number of microorganisms in the soil and improving soil porosity and water permeability. These results show that the soil conditioner of the present invention effectively improves soil fertility, improves soil structure, and enhances soil microbial activity through a comprehensive mechanism of action, thereby helping to improve crop yield and quality.

[0195] Further analysis revealed that the soil conditioner of Example 2 performed best in various performance indicators, which may be related to the raw material mixing ratio, the activity of probiotics and the preparation process of the soil conditioner. In Example 2, the mixing ratio of biochar, diatomaceous earth, probiotics and chelated calcium magnesium fertilizers is more reasonable, and the probiotics use mixed fermentation culture fluid to enhance their activity and soil adaptability. In addition, during the preparation process, Example 2 uses a lower temperature for fermentation, which may be more conducive to the growth and decomposition of microorganisms, thereby improving the effect of the soil conditioner.

[0196] In summary, the soil conditioner of the present invention achieves effective improvement of saline-alkali soil through innovative formula and preparation method. The soil conditioner not only improves the fertility and structural properties of the soil, but also significantly enhances the activity of soil microorganisms, providing a good soil environment for the growth of crops. Therefore, the soil conditioner of the present invention has broad application prospects in saline-alkali land improvement and agricultural sustainable development.

[0197] In summary, the soil conditioner formula and preparation method of the present invention have significant practical value and application prospects, can provide an effective soil improvement solution for agricultural production, and contribute to the realization of sustainable agricultural development.

[0198] 3. Principle and Mechanism

[0199] 1. Biochar

[0200] Pore ​​structure: Biochar is a material with a rich pore structure. It has a large number of micropores and mesopores at the microscopic level. These pores can increase the permeability of the soil, promote the penetration of air and water, and improve the air permeability of the soil.

[0201] Adsorption: The surface of biochar has a strong adsorption capacity, which can absorb harmful substances, heavy metals and excess fertilizer components such as nitrogen and phosphorus in the soil, reducing their negative impact on the environment. At the same time, biochar can also absorb water and improve the water retention capacity of the soil.

[0202] Soil microbial habitat: Biochar provides a good microbial habitat, which is conducive to the reproduction and growth of microorganisms, thereby improving the soil microbial community structure and enhancing the biological activity of the soil.

[0203] 2. Humic acid

[0204] Ion exchange: Humic acid is a complex organic acid with strong anion exchange capacity, which can exchange with cations in the soil (such as calcium, magnesium, sodium, etc.). It can effectively increase the cation exchange capacity (CEC) of the soil and promote the absorption of plant nutrients by the soil.

[0205] Hydration: Humic acid can absorb a large amount of water, forming a sticky colloidal substance, which enhances the soil's ability to retain water. This is very important for crop growth in arid environments.

[0206] Improvement of soil structure: Humic acid increases the binding force between soil particles to form a more stable aggregate structure, thereby improving the soil structure and enhancing the soil's air permeability and water permeability.

[0207] Microbial activity: Humic acid can also promote microbial activity in the soil and provide nutrients for them, especially the promotion of beneficial microorganisms such as nitrogen-fixing bacteria and decomposing bacteria, which helps to naturally improve soil fertility.

[0208] 3. Probiotics

[0209] Nitrogen fixation: Certain probiotics (such as rhizobia) can coexist with plant roots, converting nitrogen in the air into nitrogen sources that can be absorbed by plants, directly increasing the nitrogen content of the soil and improving the nutrient supply of the soil.

[0210] Decomposition of organic matter: Probiotics can decompose organic matter in the soil, especially complex organic waste (such as plant residues, animal feces, etc.), converting them into nutrients that can be used by plants (such as amino acids, sugars, etc.), thereby enhancing soil fertility.

[0211] Inhibition of pathogenic microorganisms: Certain probiotics (such as lactic acid bacteria and Bacillus subtilis) have antibacterial effects and can inhibit the growth of harmful pathogens (such as fungi and bacteria) in the soil, thereby improving the disease resistance of plants.

[0212] Improve soil microbial environment: Probiotics can regulate the microbial community structure in the soil, increase the number and activity of beneficial bacteria, and thus improve soil biodiversity and soil health.

[0213] 4. Chelated calcium magnesium fertilizer

[0214] Chelation: Chelating agents (such as EDTA, amino acids) can form stable chelates with calcium and magnesium ions, preventing these ions from reacting or precipitating with other ions in the soil, thereby increasing their effectiveness. This chelate has a high solubility and can be absorbed by plant roots.

[0215] Improve nutrient absorption efficiency: The use of chelated calcium-magnesium fertilizers can effectively improve the absorption efficiency of calcium and magnesium. These mineral elements are essential for the cell wall structure, photosynthesis, enzyme activity, etc. of plants.

[0216] Improve the acid-base balance of the soil: Calcium magnesium fertilizers can adjust the pH value of the soil, especially increase the pH of acidic soil, making it more suitable for plant growth.

[0217] Strengthen soil structure: Calcium and magnesium are key elements for strengthening soil structure. They can promote the formation of stable colloidal substances between soil particles, improve the aggregate structure of soil, and enhance the water holding capacity and air permeability of soil.

[0218] 5. Diatomaceous earth

[0219] Improve soil structure: Diatomaceous earth contains a large amount of siliceous particles, which can fill the gaps between soil particles and increase soil stability and structure. Diatomaceous earth can improve soil water permeability and air circulation.

[0220] Mineral supply: Diatomaceous earth is a rich source of minerals, providing the necessary mineral elements in the soil and promoting plant growth, which is especially important for crops with high mineral element requirements.

[0221] Adsorption and filtration effects: Diatomaceous earth has good adsorption properties and can absorb harmful substances in the soil (such as heavy metals, pesticide residues, etc.) to reduce their harm to plants.

[0222] 6. Comprehensive mechanism of action

[0223] From a microscopic perspective, biochar, humic acid, probiotics, chelated calcium and magnesium fertilizers, and diatomaceous earth interact with each other to form a multi-level, multi-mechanism soil improvement system. Together, they improve soil quality and promote plant growth in the following ways:

[0224] Biochar improves soil aeration and water retention through its porous structure and provides a habitat for microorganisms in the soil. Humic acid enhances soil fertility by ion exchange, improving soil hydration, promoting soil structure improvement and enhancing microbial activity. Probiotics improve the biological properties of soil by decomposing organic matter, promoting nitrogen fixation and inhibiting pathogenic microorganisms. Chelated calcium and magnesium fertilizers enhance the biological effectiveness of calcium and magnesium through stable chelation, improve soil pH and enhance soil structure. Diatomaceous earth enhances soil health by providing minerals, improving soil structure and absorbing harmful substances.

[0225] This multi-dimensional, synergistic soil improvement mechanism enables soil conditioners to comprehensively improve soil quality, promote plant growth, and effectively increase crop yield and quality.

[0226] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing a multifunctional soil conditioner for improving saline-alkali land, characterized in that: include: The biochar, diatomaceous earth, probiotics and chelated calcium magnesium fertilizer are mixed and fermented, and after the fermentation is completed, they are dried and crushed to obtain the multifunctional soil conditioner for improving saline-alkali land; The preparation method of the chelated calcium-magnesium fertilizer comprises: mixing and dissolving a calcium source and a magnesium source to obtain a calcium-magnesium solution, adding a chelating agent to the calcium-magnesium solution, heating and stirring to obtain a calcium-magnesium chelate, and adding a plant extract to the calcium-magnesium chelate to obtain the chelated calcium-magnesium fertilizer.

2. The method for preparing the multifunctional soil conditioner for improving saline-alkali land according to claim 1, characterized in that: The weight ratio of the biochar, diatomaceous earth, probiotics and chelated calcium magnesium fertilizer is 5-8:2-4:1-2:3-7.

3. The method for preparing the multifunctional soil conditioner for improving saline-alkali land according to claim 1, characterized in that: The method for preparing the biochar comprises: Biomass organic matter, seaweed powder and trace elements are mixed and carbonized to obtain primary charcoal; and humic acid is used to modify the primary charcoal to obtain the biochar.

4. The method for preparing the multifunctional soil conditioner for improving saline-alkali land according to claim 3, characterized in that: The method of modifying the primary carbon by using humic acid to obtain the biochar comprises: The primary charcoal and humic acid are mixed and stirred at 20-30° C., and the biochar is obtained after natural cooling; Wherein, the added amount of the humic acid is 5%-10% of the mass of the primary carbon.

5. The method for preparing the multifunctional soil conditioner for improving saline-alkali land according to claim 4, characterized in that: The preparation method of humic acid comprises: Wetting the plant waste and mixing it with microorganisms for fermentation, and then obtaining a humic acid solution by soaking and filtering; and drying the humic acid solution to obtain the humic acid; The mixed fermentation conditions are 25-35°C and 15-30 days; the microorganisms include yeast and lactic acid bacteria.

6. The method for preparing the multifunctional soil conditioner for improving saline-alkali land according to claim 1, characterized in that: The probiotics include Bacillus subtilis, Bacillus licheniformis, rhizobium, lactic acid bacteria and yeast.

7. The method for preparing the multifunctional soil conditioner for improving saline-alkali land according to claim 1, characterized in that: The calcium source is lime powder and gypsum; And / or, the magnesium source is magnesium sulfate. And / or, the chelating agent is EDTA; And / or, the plant extract is a tomato extract.

8. The method for preparing the multifunctional soil conditioner for improving saline-alkali land according to claim 1, characterized in that: The plant extract is tomato extract.

9. A multifunctional soil conditioner for improving saline-alkali land, characterized in that: The multifunctional soil conditioner for improving saline-alkali land is prepared according to the preparation method of any one of claims 1 to 8.

10. Use of the multifunctional soil conditioner for improving saline-alkali land according to claim 9, characterized in that: The application includes at least one of the following: A1) Application of the multifunctional soil conditioner for improving saline-alkali land in preparing plant fertilizer; A2) Application of the multifunctional soil conditioner for improving saline-alkali land in improving soil properties; A3) Application of the multifunctional soil conditioner for improving saline-alkali land in promoting plant growth.