A soil conditioner for black soil fertility recovery and a preparation method thereof

Abstract

The application relates to the technical field of soil improvers, in particular to a soil improver for restoring the fertility of black soil and a preparation method thereof. The soil improver for restoring the fertility of black soil comprises the following raw materials in parts by weight: 50-70 parts of a composite organic matrix, 4-10 parts of a nutrient chelation synergist and 8-15 parts of a humic acid derivative. The preparation method of the soil improver for restoring the fertility of black soil is as follows: the composite organic matrix and the nutrient chelation synergist are put into a mixing machine, stirred, the humic acid derivative is added, and the soil improver for restoring the fertility of black soil is obtained after uniform mixing. The soil improver has a significant beneficial effect on restoring the fertility of black soil, the pH value of the improved soil is obviously increased, the problem of acid degeneration can be effectively improved, the soil capacity is reduced, the total void ratio is increased, the soil looseness is optimized, the growth of crop roots is facilitated, and the fertility of black soil can be efficiently restored.

Description

Technical Field

[0001] This application relates to the field of soil conditioner technology, and more specifically, to a soil conditioner for restoring fertility in black soil and its preparation method. Background Technology

[0002] Existing black soil improvement technologies mainly include straw return to the field, increased application of organic fertilizer, deep tillage, crop rotation and fallow, and application of single soil amendments. While straw return can replenish organic matter, its long decomposition period makes it susceptible to pests and diseases, and its effect on improving soil structure is limited. Traditional organic fertilizers suffer from nutrient imbalances, the risk of heavy metal contamination, and high application costs. Single mineral amendments (such as lime and zeolite) can only improve local physicochemical properties and cannot simultaneously address the problems of organic matter deficiency and insufficient microbial activity. Biological agents have drawbacks such as short lifespan, high susceptibility to environmental influences, and slow effectiveness. Currently, there is a lack of a comprehensive improvement technology that can simultaneously achieve organic matter replenishment, soil structure restoration, microbial activation, and nutrient balance regulation. Existing amendments generally suffer from single efficacy, poor stability, high cost, and complex application, making it difficult to meet the actual needs of large-scale rapid restoration of black soil fertility. Therefore, developing a specialized soil conditioner with synergistic components, long-lasting effects, environmental friendliness, and suitability for the degradation characteristics of black soil, as well as its efficient preparation method, is of great practical significance for curbing the degradation trend of black soil, improving the quality of arable land, and ensuring food security. Summary of the Invention

[0003] To address the technical problems mentioned in the background section, this application provides a soil conditioner for restoring fertility in black soil and its preparation method.

[0004] Firstly, this application provides a soil conditioner for restoring fertility in black soil, employing the following technical solution: A soil conditioner for restoring fertility in black soil comprises the following raw materials in parts by weight: 50-70 parts of composite organic matrix, 4-10 parts of nutrient chelating synergist, and 8-15 parts of humic acid derivative.

[0005] Preferably, the composite organic matrix includes the following preparation steps: Mix well-rotted corn stalks, sheep manure organic fertilizer, earthworm castings, and modified mineral matrix to obtain a mixture; inoculate the mixture with a functional compound microbial agent, and ferment it at a constant temperature of 50-60℃ and humidity of 60-70% for 8-10 days, turning it over regularly during the fermentation process. After fermentation, dry it at low temperature until the moisture content is ≤15%, crush it, and sieve it to obtain a compound organic matrix.

[0006] Preferably, the degree of decomposition of the corn stalks is ≥85%; the sheep manure organic fertilizer is subjected to high-temperature composting and decomposition treatment, with the composting temperature maintained at 55-65℃, the organic matter content is ≥45%, and the total content of N+P2O5+K2O is ≥5.0%.

[0007] Preferably, the method for preparing the modified mineral matrix is ​​as follows: A 5-8% hydrochloric acid solution, zeolite, bentonite, and diatomaceous earth are mixed and stirred evenly. The mixture is then stirred and reacted at 60-80℃ for 2-3 hours. After filtration, washing, and drying, the modified mineral matrix is ​​obtained.

[0008] Preferably, the mass ratio of the decomposed corn stalks, sheep manure organic fertilizer, earthworm castings, and modified mineral matrix is ​​10-15:5-8:3-6:1-3.

[0009] Preferably, the inoculation amount of the functional compound microbial agent is 2-4% of the mass of the mixture; the functional compound microbial agent is composed of Bacillus subtilis, phosphorus-solubilizing and potassium-solubilizing bacteria and Bacillus mucilaginosus with an effective viable count ratio of 8-10:4-6:1-3.

[0010] Preferably, the temperature for the low-temperature drying is 40-45°C.

[0011] Preferably, the nutrient chelating synergist is composed of EDTA-chelated iron-zinc-calcium complex salt and trehalose in a mass ratio of 2-5:1-2; the total content of iron, zinc and calcium in the EDTA-chelated iron-zinc-calcium complex salt is ≥18%, and the chelation rate is ≥90%.

[0012] Preferably, the humic acid derivative is nitrohumic acid and / or potassium humate, wherein the humic acid content of the humic acid derivative is ≥70%.

[0013] Secondly, this application also provides a method for preparing a soil conditioner for restoring fertility in black soil, employing the following technical solution: A method for preparing a soil conditioner for restoring fertility in black soil includes the following preparation steps: Add the composite organic matrix and nutrient chelating synergist into a mixer and stir for 20-30 minutes. Then add the humic acid derivative and mix evenly to obtain a soil conditioner for restoring fertility in black soil.

[0014] In summary, this application has the following beneficial effects: This application utilizes a scientifically formulated blend of Bacillus subtilis, phosphorus- and potassium-solubilizing bacteria, and Bacillus mucilaginosus, combined with high-temperature composting of sheep manure organic fertilizer, synergistic application of trehalose and EDTA chelated iron-zinc-calcium complex salts, and precise addition of modified mineral matrix. This results in a soil conditioner that demonstrates significant advantages in restoring fertility in black soil, comprehensively improving soil structure and enhancing nutrient supply capacity, thus creating a high-quality soil environment for crop growth. By combining Bacillus subtilis, phosphorus- and potassium-solubilizing bacteria, and Bacillus mucilaginosus in a specific ratio, the three strains exert a synergistic effect, more efficiently decomposing insoluble nutrients in the soil and converting fixed phosphorus and potassium elements into forms that crops can absorb and utilize. Simultaneously, Bacillus subtilis inhibits the proliferation of harmful soil bacteria, while Bacillus mucilaginosus promotes the formation of soil aggregates. The three work synergistically to maintain soil microecological balance and enhance soil resilience. High-temperature composting of sheep manure organic fertilizer completely kills harmful bacteria, insect eggs, and weed seeds, preventing uncomposted manure from entering the soil and causing pests and diseases. High-temperature composting also promotes the full decomposition of organic matter, increasing organic matter content and total nutrient levels, making nutrients easier for crops to absorb. Compared to raw materials that are not composted at high temperatures, this method better ensures soil health and stable fertility supply. The addition of a properly proportioned blend of trehalose and EDTA-chelated iron-zinc-calcium complex salt significantly enhances the performance of the nutrient chelating synergist. Trehalose improves the stability of EDTA chelated salts, reducing nutrient loss and fixation in the soil, promoting crop absorption of micronutrients such as iron, zinc, and calcium. Furthermore, trehalose protects the activity of beneficial bacteria in the soil, enhances crop resistance, and significantly improves nutrient utilization. By adding modified mineral matrix, the soil's water retention, fertilizer retention, and aeration are improved. The modified mineral matrix has a larger specific surface area and enhanced adsorption capacity, which can effectively adsorb nutrients and heavy metal ions in the soil, preventing nutrient loss and soil pollution. At the same time, it can improve the problem of heavy and compacted black soil, providing a good environment for microbial activity and crop root growth. Compared with the formula without mineral matrix, the physical properties and fertility persistence of the soil are significantly optimized. Detailed Implementation

[0015] The present application will be further described in detail below with reference to the embodiments.

[0016] The nitrohumic acid (humic acid content: 70%) used in the examples and comparative examples of this application was purchased from Wuhan Jiyesheng Chemical Co., Ltd.; EDTA chelated iron-zinc-calcium complex salt was purchased from Shandong Gushuo Biotechnology Co., Ltd.; trehalose was purchased from Hangzhou Tianhong Chemical Co., Ltd.; Bacillus subtilis (viable count ≥ 5 billion / g) was purchased from Beihai Qunlin Biological Factory Store; phosphorus-solubilizing and potassium-solubilizing bacteria were purchased from Guangzhou Weiyuan Biotechnology Co., Ltd.; Bacillus mucilaginosus (viable count ≥ 5 billion / g) was purchased from Guangxi Kanglv Biotechnology Co., Ltd.; zeolite (porosity: 2%) was purchased from Baojiatun Xingye Zeolite Powder Factory in Faku County; bentonite was purchased from Shijiazhuang Aiyu Mineral Products Co., Ltd.; and diatomite was purchased from Shijiazhuang Mengyu New Material Technology Co., Ltd.

[0017] Examples 1-3 provide a soil conditioner for restoring fertility in black soil and its preparation method.

[0018] Example 1 A soil conditioner for restoring fertility in black soil comprises the following raw materials in parts by weight: 50 parts of composite organic matrix, 4 parts of nutrient chelating synergist, and 8 parts of humic acid derivative; wherein the nutrient chelating synergist is composed of EDTA chelated iron-zinc-calcium composite salt and trehalose in a mass ratio of 2:1, the total content of iron, zinc and calcium in the EDTA chelated iron-zinc-calcium composite salt is 18%, and the chelation rate is 90%; the humic acid derivative is nitrohumic acid.

[0019] The composite organic matrix includes the following preparation steps: Well-rotted corn stalks, sheep manure organic fertilizer, earthworm castings, and modified mineral matrix were mixed in a mass ratio of 10:5:3:1 to obtain a mixture. A functional compound microbial agent was inoculated into the mixture at an inoculation rate of 2% of the mixture's mass. The mixture was then fermented at a constant temperature of 50℃ and 60% humidity for 8 days, with the mixture being turned over every 20 hours during fermentation. After fermentation, the mixture was dried at 40℃ until the moisture content reached 15%, then pulverized and passed through a 100-mesh sieve to obtain the composite organic matrix. The well-rotted corn stalks had a composting degree of 85%. The sheep manure organic fertilizer underwent high-temperature composting treatment, with the composting temperature maintained at 55℃, resulting in an organic matter content of 45% and a total N+P2O5+K2O content of 5.0%. The functional compound microbial agent consisted of Bacillus subtilis, phosphorus-solubilizing and potassium-solubilizing bacteria, and Bacillus mucilaginosus in an effective viable bacteria ratio of 8:4:1. The preparation method of the modified mineral matrix is ​​as follows: A 5% hydrochloric acid solution, zeolite, bentonite, and diatomaceous earth were mixed in a mass ratio of 20:5:2:1. The mixture was stirred at 200 rpm until homogeneous, and then stirred at 60°C for 2 hours. The mixture was then filtered, washed three times with deionized water, and dried at 60°C for 10 hours to obtain the modified mineral matrix.

[0020] A method for preparing a soil conditioner for restoring fertility in black soil includes the following preparation steps: The composite organic matrix and nutrient chelating synergist are put into a mixer and stirred at 200 rpm for 20 minutes. Then, humic acid derivatives are added and stirred at 400 rpm. After mixing evenly, a soil conditioner for restoring fertility in black soil is obtained.

[0021] Example 2 A soil conditioner for restoring fertility in black soil comprises the following raw materials in parts by weight: 60 parts of composite organic matrix, 8 parts of nutrient chelating synergist, and 12 parts of humic acid derivative; wherein the nutrient chelating synergist is composed of EDTA chelated iron-zinc-calcium composite salt and trehalose in a mass ratio of 4:1.5, the total content of iron, zinc and calcium in the EDTA chelated iron-zinc-calcium composite salt is 20%, and the chelation rate is 92%; the humic acid derivative is nitrohumic acid.

[0022] The composite organic matrix includes the following preparation steps: Well-rotted corn stalks, sheep manure organic fertilizer, earthworm castings, and modified mineral matrix were mixed in a mass ratio of 12:7:5:2 to obtain a mixture. A functional compound microbial agent was inoculated into the mixture at an inoculation rate of 3% of the mixture's mass. The mixture was then fermented at a constant temperature of 55℃ and 65% humidity for 9 days, with the mixture being turned over every 22 hours during fermentation. After fermentation, the mixture was dried at 42℃ until the moisture content reached 12%, then pulverized and passed through a 100-mesh sieve to obtain the composite organic matrix. The well-rotted corn stalks had a composting degree of 88%. The sheep manure organic fertilizer underwent high-temperature composting treatment, with the composting temperature maintained at 60℃, resulting in an organic matter content of 48% and a total N+P2O5+K2O content of 5.5%. The functional compound microbial agent consisted of Bacillus subtilis, phosphorus-solubilizing and potassium-solubilizing bacteria, and Bacillus mucilaginosus in an effective viable bacteria ratio of 9:5:2. The preparation method of the modified mineral matrix is ​​as follows: A 7% hydrochloric acid solution, zeolite, bentonite, and diatomaceous earth were mixed in a mass ratio of 25:6:4:2. The mixture was stirred evenly at 250 rpm and reacted at 70°C for 2.5 h. The mixture was then filtered, washed four times with deionized water, and dried at 70°C for 11 h to obtain the modified mineral matrix.

[0023] A method for preparing a soil conditioner for restoring fertility in black soil includes the following preparation steps: The composite organic matrix and nutrient chelating synergist are put into a mixer and stirred at 250 rpm for 25 minutes. Then, humic acid derivatives are added and stirred at 450 rpm. After mixing evenly, a soil conditioner for restoring fertility in black soil is obtained.

[0024] Example 3 A soil conditioner for restoring fertility in black soil comprises the following raw materials in parts by weight: 70 parts of composite organic matrix, 10 parts of nutrient chelating synergist, and 15 parts of humic acid derivative; wherein the nutrient chelating synergist is composed of EDTA chelated iron-zinc-calcium composite salt and trehalose in a mass ratio of 5:2, the total content of iron, zinc and calcium in the EDTA chelated iron-zinc-calcium composite salt is 22%, and the chelation rate is 95%; the humic acid derivative is nitrohumic acid.

[0025] The composite organic matrix includes the following preparation steps: Well-rotted corn stalks, sheep manure organic fertilizer, earthworm castings, and modified mineral matrix were mixed in a mass ratio of 15:8:6:3 to obtain a mixture. A functional compound microbial agent was inoculated into the mixture at an inoculation rate of 4% of the mixture mass. The mixture was then fermented at a constant temperature of 60℃ and 70% humidity for 10 days, with the mixture being turned over every 24 hours during fermentation. After fermentation, the mixture was dried at 45℃ until the moisture content was 10%, then pulverized and passed through a 100-mesh sieve to obtain the composite organic matrix. The well-rotted corn stalks had a 90% degree of decomposition. The sheep manure organic fertilizer underwent high-temperature composting, with the composting temperature maintained at 65℃, resulting in an organic matter content of 50% and a total N+P2O5+K2O content of 6.0%. The functional compound microbial agent consisted of Bacillus subtilis, phosphorus-solubilizing and potassium-solubilizing bacteria, and Bacillus mucilaginosus in an effective viable bacteria ratio of 10:6:3. The preparation method of the modified mineral matrix is ​​as follows: An 8% hydrochloric acid solution, zeolite, bentonite, and diatomaceous earth were mixed in a mass ratio of 30:7:5:3. The mixture was stirred at 300 rpm until homogeneous, and then stirred at 80°C for 3 hours. The mixture was then filtered, washed five times with deionized water, and dried at 80°C for 12 hours to obtain the modified mineral matrix.

[0026] A method for preparing a soil conditioner for restoring fertility in black soil includes the following preparation steps: The composite organic matrix and nutrient chelating synergist are put into a mixer and stirred at 300 rpm for 30 minutes. Then, humic acid derivatives are added and stirred at 500 rpm. After mixing evenly, a soil conditioner for restoring fertility in black soil is obtained.

[0027] Comparative Example 1 A soil conditioner for restoring fertility in black soil comprises the following raw materials in parts by weight: 50 parts of composite organic matrix, 4 parts of nutrient chelating synergist, and 8 parts of humic acid derivative; wherein the nutrient chelating synergist is composed of EDTA chelated iron-zinc-calcium composite salt and trehalose in a mass ratio of 2:1, the total content of iron, zinc and calcium in the EDTA chelated iron-zinc-calcium composite salt is 18%, and the chelation rate is 90%; the humic acid derivative is nitrohumic acid.

[0028] The composite organic matrix includes the following preparation steps: Well-rotted corn stalks, sheep manure, earthworm castings, and modified mineral matrix were mixed in a mass ratio of 10:5:3:1 to obtain a mixture. A functional compound microbial agent was inoculated into the mixture at an inoculation rate of 2% of the mixture's mass. The mixture was then fermented at a constant temperature of 50℃ and 60% humidity for 8 days, with the mixture being turned over every 20 hours during fermentation. After fermentation, the mixture was dried at 40℃ until the moisture content reached 15%, then pulverized and passed through a 100-mesh sieve to obtain a composite organic matrix. The well-rotted corn stalks had a decomposition degree of 85%. The functional compound microbial agent consisted of Bacillus subtilis, phosphorus-solubilizing and potassium-solubilizing bacteria, and Bacillus mucilaginosus in an effective viable bacteria ratio of 8:4:1. The preparation method of the modified mineral matrix is ​​as follows: A 5% hydrochloric acid solution, zeolite, bentonite, and diatomaceous earth were mixed in a mass ratio of 20:5:2:1. The mixture was stirred at 200 rpm until homogeneous, and then stirred at 60°C for 2 hours. The mixture was then filtered, washed three times with deionized water, and dried at 60°C for 10 hours to obtain the modified mineral matrix.

[0029] A method for preparing a soil conditioner for restoring fertility in black soil includes the following preparation steps: The composite organic matrix and nutrient chelating synergist are put into a mixer and stirred at 200 rpm for 20 minutes. Then, humic acid derivatives are added and stirred at 400 rpm. After mixing evenly, a soil conditioner for restoring fertility in black soil is obtained.

[0030] Comparative Example 2 A soil conditioner for restoring fertility in black soil comprises the following raw materials in parts by weight: 50 parts of composite organic matrix, 4 parts of nutrient chelating synergist, and 8 parts of humic acid derivative; wherein the nutrient chelating synergist is composed of EDTA chelated iron-zinc-calcium composite salt and trehalose in a mass ratio of 2:1, the total content of iron, zinc and calcium in the EDTA chelated iron-zinc-calcium composite salt is 18%, and the chelation rate is 90%; the humic acid derivative is nitrohumic acid.

[0031] The composite organic matrix includes the following preparation steps: Well-rotted corn stalks, sheep manure organic fertilizer, earthworm castings, and modified mineral matrix were mixed in a mass ratio of 10:5:3:1 to obtain a mixture. A functional compound microbial agent was inoculated into the mixture at an inoculation rate of 2% of the mixture's mass. The mixture was then fermented at a constant temperature of 50℃ and 60% humidity for 8 days, with the mixture being turned over every 20 hours during fermentation. After fermentation, the mixture was dried at 40℃ until the moisture content reached 15%, then pulverized and passed through a 100-mesh sieve to obtain the composite organic matrix. The well-rotted corn stalks had a composting degree of 85%. The sheep manure organic fertilizer underwent high-temperature composting treatment, with the composting temperature maintained at 55℃, resulting in an organic matter content of 45% and a total N+P2O5+K2O content of 5.0%. The functional compound microbial agent consisted of Bacillus subtilis and Bacillus mucilaginosus with an effective viable bacteria ratio of 8:1. The preparation method of the modified mineral matrix is ​​as follows: A 5% hydrochloric acid solution, zeolite, bentonite, and diatomaceous earth were mixed in a mass ratio of 20:5:2:1. The mixture was stirred at 200 rpm until homogeneous, and then stirred at 60°C for 2 hours. The mixture was then filtered, washed three times with deionized water, and dried at 60°C for 10 hours to obtain the modified mineral matrix.

[0032] A method for preparing a soil conditioner for restoring fertility in black soil includes the following preparation steps: The composite organic matrix and nutrient chelating synergist are put into a mixer and stirred at 200 rpm for 20 minutes. Then, humic acid derivatives are added and stirred at 400 rpm. After mixing evenly, a soil conditioner for restoring fertility in black soil is obtained.

[0033] Comparative Example 3 A soil conditioner for restoring fertility in black soil comprises the following raw materials in parts by weight: 50 parts of composite organic matrix, 4 parts of nutrient chelating synergist, and 8 parts of humic acid derivative; wherein the nutrient chelating synergist is composed of EDTA chelated iron-zinc-calcium composite salt and trehalose in a mass ratio of 2:1, the total content of iron, zinc and calcium in the EDTA chelated iron-zinc-calcium composite salt is 18%, and the chelation rate is 90%; the humic acid derivative is nitrohumic acid.

[0034] The composite organic matrix includes the following preparation steps: Well-rotted corn stalks, sheep manure organic fertilizer, earthworm castings, and modified mineral matrix were mixed in a mass ratio of 10:5:3:1 to obtain a mixture. A functional compound microbial agent was inoculated into the mixture at an inoculation rate of 2% of the mixture's mass. The mixture was then fermented at a constant temperature of 50℃ and 60% humidity for 8 days, with the mixture being turned over every 20 hours during fermentation. After fermentation, the mixture was dried at 40℃ until the moisture content reached 15%, then pulverized and passed through a 100-mesh sieve to obtain the composite organic matrix. The well-rotted corn stalks had a composting degree of 85%. The sheep manure organic fertilizer underwent high-temperature composting treatment, with the composting temperature maintained at 55℃, resulting in an organic matter content of 45% and a total N+P2O5+K2O content of 5.0%. The functional compound microbial agent consisted of Bacillus subtilis and phosphorus- and potassium-solubilizing bacteria in an effective viable bacteria ratio of 8:4. The preparation method of the modified mineral matrix is ​​as follows: A 5% hydrochloric acid solution, zeolite, bentonite, and diatomaceous earth were mixed in a mass ratio of 20:5:2:1. The mixture was stirred at 200 rpm until homogeneous, and then stirred at 60°C for 2 hours. The mixture was then filtered, washed three times with deionized water, and dried at 60°C for 10 hours to obtain the modified mineral matrix.

[0035] A method for preparing a soil conditioner for restoring fertility in black soil includes the following preparation steps: The composite organic matrix and nutrient chelating synergist are put into a mixer and stirred at 200 rpm for 20 minutes. Then, humic acid derivatives are added and stirred at 400 rpm. After mixing evenly, a soil conditioner for restoring fertility in black soil is obtained.

[0036] Comparative Example 4 A soil conditioner for restoring fertility in black soil comprises the following raw materials in parts by weight: 50 parts of composite organic matrix, 4 parts of nutrient chelating synergist, and 8 parts of humic acid derivative; wherein the nutrient chelating synergist is EDTA chelated iron-zinc-calcium composite salt, the total content of iron, zinc, and calcium in the EDTA chelated iron-zinc-calcium composite salt is 18%, and the chelation rate is 90%; the humic acid derivative is nitrohumic acid.

[0037] The composite organic matrix includes the following preparation steps: Well-rotted corn stalks, sheep manure organic fertilizer, earthworm castings, and modified mineral matrix were mixed in a mass ratio of 10:5:3:1 to obtain a mixture. A functional compound microbial agent was inoculated into the mixture at an inoculation rate of 2% of the mixture's mass. The mixture was then fermented at a constant temperature of 50℃ and 60% humidity for 8 days, with the mixture being turned over every 20 hours during fermentation. After fermentation, the mixture was dried at 40℃ until the moisture content reached 15%, then pulverized and passed through a 100-mesh sieve to obtain the composite organic matrix. The well-rotted corn stalks had a composting degree of 85%. The sheep manure organic fertilizer underwent high-temperature composting treatment, with the composting temperature maintained at 55℃, resulting in an organic matter content of 45% and a total N+P2O5+K2O content of 5.0%. The functional compound microbial agent consisted of Bacillus subtilis, phosphorus-solubilizing and potassium-solubilizing bacteria, and Bacillus mucilaginosus in an effective viable bacteria ratio of 8:4:1. The preparation method of the modified mineral matrix is ​​as follows: A 5% hydrochloric acid solution, zeolite, bentonite, and diatomaceous earth were mixed in a mass ratio of 20:5:2:1. The mixture was stirred at 200 rpm until homogeneous, and then stirred at 60°C for 2 hours. The mixture was then filtered, washed three times with deionized water, and dried at 60°C for 10 hours to obtain the modified mineral matrix.

[0038] A method for preparing a soil conditioner for restoring fertility in black soil includes the following preparation steps: The composite organic matrix and nutrient chelating synergist are put into a mixer and stirred at 200 rpm for 20 minutes. Then, humic acid derivatives are added and stirred at 400 rpm. After mixing evenly, a soil conditioner for restoring fertility in black soil is obtained.

[0039] Comparative Example 5 A soil conditioner for restoring fertility in black soil comprises the following raw materials in parts by weight: 50 parts of composite organic matrix, 4 parts of nutrient chelating synergist, and 8 parts of humic acid derivative; wherein the nutrient chelating synergist is composed of EDTA chelated iron-zinc-calcium composite salt and trehalose in a mass ratio of 2:1, the total content of iron, zinc and calcium in the EDTA chelated iron-zinc-calcium composite salt is 18%, and the chelation rate is 90%; the humic acid derivative is nitrohumic acid.

[0040] The composite organic matrix includes the following preparation steps: Well-rotted corn stalks, sheep manure organic fertilizer, and earthworm castings were mixed in a mass ratio of 10:5:3 to obtain a mixture. A functional compound microbial agent was inoculated into the mixture at an inoculation rate of 2% of the mixture's mass. The mixture was then fermented at a constant temperature of 50℃ and 60% humidity for 8 days, with the mixture being turned over every 20 hours during fermentation. After fermentation, the mixture was dried at 40℃ until the moisture content reached 15%, then pulverized and passed through a 100-mesh sieve to obtain a composite organic matrix. The well-rotted corn stalks had a composting degree of 85%. The sheep manure organic fertilizer underwent high-temperature composting treatment, with the composting temperature maintained at 55℃, resulting in an organic matter content of 45% and a total N+P2O5+K2O content of 5.0%. The functional compound microbial agent consisted of Bacillus subtilis, phosphorus-solubilizing and potassium-solubilizing bacteria, and Bacillus mucilaginosus in an effective viable bacteria ratio of 8:4:1. A method for preparing a soil conditioner for restoring fertility in black soil includes the following preparation steps: The composite organic matrix and nutrient chelating synergist are put into a mixer and stirred at 200 rpm for 20 minutes. Then, humic acid derivatives are added and stirred at 400 rpm. After mixing evenly, a soil conditioner for restoring fertility in black soil is obtained.

[0041] Performance testing The soil conditioners for restoring fertility of black soil prepared in Examples 1-3 and Comparative Examples 1-5 were applied to the improvement of acidic black soil in Northeast China. The test soils were taken from the degraded acidic area of ​​black soil in Northeast China. The soil type was black calcareous soil. After pretreatment (removing stones and weed roots, air drying and passing through a 2mm sieve), the initial physicochemical properties are shown in Table 1. All indicators are consistent with the characteristics of acidic black soil degradation. Table 1 Physicochemical properties of acidic soils in Northeast China's black soil region All field management practices (irrigation, weeding, etc.) for the experimental soils were consistent and conformed to local black soil cultivation standards. The specific application method strictly followed the procedures below: Each experimental soil was treated with deep tillage and loosening equipment to break up the soil to a depth of 25cm, breaking up the compacted soil layer; then, the soil conditioner from Examples 1-3 and Comparative Examples 1-5 was evenly applied at a rate of 50kg per acre. The control group received no soil conditioner and only underwent conventional field management. Immediately after application, a rotary tiller was used to plow and mix the soil to a depth of 15cm to ensure uniform mixing of the soil and soil conditioner; subsequent field management was carried out according to conventional methods, avoiding the input of exogenous nutrients that could affect the test results; two months after soil improvement, samples were taken from each experimental soil for testing. Five sampling points were randomly selected for each test soil. A 10cm topsoil sample was collected from each sampling point. The soil samples from the five sampling points of the same test soil were mixed evenly and impurities were removed. The quartering method was used to retain the sample to be tested. The following indicators were measured respectively. All indicators were measured in parallel three times and the average value was taken as the final test result. The test results are shown in Table 2. Table 2. Parameters showing changes in soil physicochemical properties after application of soil conditioners in Examples 1-3 and Comparative Examples 1-5. As shown in Table 2, the soil conditioner prepared in this application has a significant beneficial effect on the restoration of fertility in black soil. Compared with the blank group and the comparative examples, the soil pH value of the soil after improvement in Examples 1-3 was significantly increased, which can effectively improve the problem of acid degradation; the soil volume decreased, the total porosity increased, and the soil looseness was optimized, which is conducive to crop root growth. At the same time, the content of soil organic matter, organic carbon and available phosphorus increased significantly, the nutrient supply capacity was significantly enhanced, and it can efficiently restore the fertility of black soil.

[0042] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A soil conditioner for restoring fertility in black soil, characterized in that, The raw materials include the following parts by weight: 50-70 parts of composite organic matrix, 4-10 parts of nutrient chelating synergist, and 8-15 parts of humic acid derivative.

2. The soil conditioner for restoring fertility in black soil according to claim 1, characterized in that, The composite organic matrix includes the following preparation steps: Mix well-rotted corn stalks, sheep manure organic fertilizer, earthworm castings, and modified mineral matrix to obtain a mixture; inoculate the mixture with a functional compound microbial agent, and ferment it at a constant temperature of 50-60℃ and humidity of 60-70% for 8-10 days, turning it over regularly during the fermentation process. After fermentation, dry it at low temperature until the moisture content is ≤15%, crush it, and sieve it to obtain a compound organic matrix.

3. The soil conditioner for restoring fertility in black soil according to claim 2, characterized in that, The degree of decomposition of the corn stalks is ≥85%; the sheep manure organic fertilizer is subjected to high-temperature composting and decomposition treatment, with the composting temperature maintained at 55-65℃, the organic matter content is ≥45%, and the total content of N+P2O5+K2O is ≥5.0%.

4. The soil conditioner for restoring fertility in black soil according to claim 2, characterized in that, The method for preparing the modified mineral matrix is ​​as follows: A 5-8% hydrochloric acid solution, zeolite, bentonite, and diatomaceous earth are mixed and stirred evenly. The mixture is then stirred and reacted at 60-80℃ for 2-3 hours. After filtration, washing, and drying, the modified mineral matrix is ​​obtained.

5. The soil conditioner for restoring fertility in black soil according to claim 2, characterized in that, The mass ratio of the decomposed corn stalks, sheep manure organic fertilizer, earthworm castings, and modified mineral matrix is ​​10-15:5-8:3-6:1-3.

6. The soil conditioner for restoring fertility in black soil according to claim 2, characterized in that, The inoculation amount of the functional compound microbial agent is 2-4% of the mass of the mixture; the functional compound microbial agent is composed of Bacillus subtilis, phosphorus-solubilizing and potassium-solubilizing bacteria and Bacillus mucilaginosus with an effective viable count ratio of 8-10:4-6:1-3.

7. The soil conditioner for restoring fertility in black soil according to claim 2, characterized in that, The temperature for the low-temperature drying is 40-45℃.

8. The soil conditioner for restoring fertility in black soil according to claim 1, characterized in that, The nutrient chelating synergist is composed of EDTA-chelated iron-zinc-calcium complex salt and trehalose in a mass ratio of 2-5:1-2; the total content of iron, zinc and calcium in the EDTA-chelated iron-zinc-calcium complex salt is ≥18%, and the chelation rate is ≥90%.

9. The soil conditioner for restoring fertility in black soil according to claim 1, characterized in that, The humic acid derivative is nitrohumic acid and / or potassium humate, wherein the humic acid content of the humic acid derivative is ≥70%.

10. A method for preparing a soil conditioner for restoring fertility in black soil as described in any one of claims 1-9, characterized in that, The preparation steps include the following: Add the composite organic matrix and nutrient chelating synergist into a mixer and stir for 20-30 minutes. Then add the humic acid derivative and mix evenly to obtain a soil conditioner for restoring fertility in black soil.

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