Agricultural soil conditioner and preparation method thereof

Abstract

The invention discloses an agricultural soil improvement agent and a preparation method of the agricultural soil improvement agent, and belongs to the technical field of soil improvement agents. Comprising the following raw materials: 30-40 parts of soybean meal, 20-25 parts of bagasse, 15-20 parts of rice hull ash, 5-15 parts of brewer's grains, 6-12 parts of tea residues, 5-15 parts of lotus root starch, 8-10 parts of a compound microbial agent, 2-5 parts of trehalose, 15-25 parts of bentonite, 6-8 parts of turmeric powder and 5-10 parts of an inorganic chelating agent, and the compound microbial agent comprises bacillus, xylose oxidation alcaligenes denitrifying subspecies and alcaligenes faecalis. According to the invention, wastes in multiple industries are used as raw materials, the cost is reduced, neutralization of acidity is synchronously realized through biological and chemical dual effects, accumulation of nitrate and organic acids in soil is reduced through cooperation of different strains, and the synergistic effects of rapid improvement and long-acting maintenance of soil acidity and alkalinity are achieved through a dual bacteriostatic system of curcuma powder bacteriostasis and microbial bacteriostasis.

Description

Technical Field

[0001] The present invention belongs to the technical field of soil conditioners, and in particular relates to an agricultural soil conditioner and a preparation method thereof. Background Art

[0002] Soil acidification also exacerbates the harmful effects of heavy metal pollution. It increases the activity of heavy metals in the soil, leading to increased plant absorption of these harmful heavy metals. These toxic metals then enter the food chain, posing a threat to human health. Furthermore, soil acidification exacerbates plant diseases and impacts plant and soil microbial diversity.

[0003] A common method for improving acidic soils is to apply alkaline substances such as lime to directly neutralize soil acidity. This method is a traditional and effective method for improving acidic soils, but it also has some problems. Long-term, high-volume application of lime can lead to soil compaction and nutrient imbalance, as lime only provides calcium. Excessive calcium can lead to deficiencies in magnesium (Mg) and potassium (K) in the soil, as well as reduced phosphorus (P) availability. When lime application is discontinued, the soil may experience re-acidification, whereby soil acidity rises again, causing acid damage to crops. Lime has poor mobility in the soil and can generally only neutralize acidity in the topsoil (15-20 cm), with limited improvement effects in deeper soil layers (below 20 cm). Summary of the Invention

[0004] The purpose of the present invention is to provide an agricultural soil conditioner and a preparation method thereof, which can achieve short-term and long-term pH regulation of acidic soil.

[0005] The purpose of the present invention can be achieved through the following technical solutions: The present invention provides an agricultural soil conditioner, which comprises the following raw materials in parts by mass: 30-40 parts of soybean meal, 20-25 parts of bagasse, 15-20 parts of rice husk ash, 5-15 parts of brewer's grains, 6-12 parts of tea residue, 5-15 parts of lotus root starch, 8-10 parts of composite microbial agent, 2-5 parts of trehalose, 15-25 parts of bentonite, 6-8 parts of turmeric powder, and 5-10 parts of inorganic chelating agent; The bentonite is loaded with bacteria, lotus root powder, brewer's grains and trehalose are added to form a composite bacterial agent, and then bagasse, tea residue, soybean meal, rice husk ash and turmeric powder are mixed and granulated with the composite bacterial agent to form a soil improver. The composite microbial agent comprises Bacillus, Alcaligenes xylosoxidans subspecies denitrificans and Alcaligenes faecalis.

[0006] Among the above raw materials, bagasse, brewer's grains, tea residues, soybean meal and rice husk ash are all agricultural wastes. In the prior art, bagasse is often used by sugar factories as fuel for steam engines; most of the brewer's grains are discarded as waste or used as animal feed, and there is a risk of acidosis when used as animal feed; soybean meal is mainly used to make feed, but the presence of various anti-nutritional factors in soybean meal limits its further application in the feed industry. When the above wastes are used as raw materials for agricultural soil conditioners, bagasse is a loose, porous, light-weight solid that can promote soil loosening, reduce soil density and increase permeability, promote plant absorption of water and nutrients, and reduce water evaporation and soil compaction, which is beneficial to microbial activity, thereby enhancing soil fertility and disease resistance; on the other hand, the lignin and cellulose it provides can be used as nutrients for microbial strains, promote the growth of microbial strains in the soil, and improve microbial activity.

[0007] Brewer's grains contain protein, crude fiber, crude fat, ash, vitamins, minerals and enzymes, etc. Brewer's grains contain high levels of maltose, arabinose, xylose and glucose, which can become excellent nutrients for Alcaligenes xylosoxidans denitrification subspecies. Alcaligenes xylosoxidans denitrification subspecies can use nitrite as an electron acceptor to carry out denitrification, avoiding soil acidification caused by the combination of nitrite and hydrogen ions in the soil.

[0008] In addition to fiber and protein, tea dregs also contain tea polyphenols, caffeine, lysine and other ingredients. Tea polyphenols and caffeine are alkaline, which can inhibit soil acidification. They are rich in nitrogen, phosphorus, potassium and other nutrients needed by plants.

[0009] Rice husk ash is the product left after burning rice husk, and its main component is silicon dioxide (Si ), which is usually between 80% and 95%, with the remainder consisting of unburned carbon and other trace metal oxides (such as potassium oxide O, sodium oxide N O, magnesium oxide (MgO), etc.). Rice husk ash has a high specific surface area (typically 50-100 m² / g) and a porous structure, which can reduce soil compaction. Rice husk ash is alkaline, neutralizing acidic substances in the soil, thereby raising the soil pH and improving the acidic soil environment. It also replenishes potassium and magnesium in the soil, enriching the soil's elemental composition.

[0010] Furthermore, the ratio of the number of live bacteria colonies of Bacillus, Alcaligenes xylosoxidans denitrificans subspecies and Alcaligenes faecalis in the composite microbial agent is 2:1.2-1.5:0.8-1.

[0011] Bacillus decomposes organic matter, releasing nutrients and providing carbon and nitrogen sources for Alcaligenes faecalis. Alcaligenes faecalis degrades organic acids (such as acetic acid and lactic acid), reducing the accumulation of acid radicals. Using urease, Bacillus faecalis catalyzes the decomposition of residual urea in the soil into carbon dioxide and ammonia, releasing alkaline substances. Through denitrification, Bacillus faecalis can reduce nitrogen oxides to nitrogen gas and use the energy generated to fix nitrogen, providing nitrogen nutrition for plants. Alcaligenes xylosoxidans subsp. denitrificans works in conjunction with Alcaligenes faecalis to continuously regulate pH and prevent long-term, drastic fluctuations.

[0012] Furthermore, the Bacillus is at least one of Bacillus subtilis, Bacillus pumilus and Paenibacillus jelly.

[0013] Bacillus subtilis can use the cellulose and protein in brewer's spent grains as carbon and nitrogen sources to produce γ-polyglutamic acid (γ-PGA) and other bioactive substances, such as glutamic acid and amino acids. The molecular structure of γ-PGA contains carboxyl and amino groups, which give it acidity and alkalinity. In acidic environments, the carboxyl groups are protonated, while in alkaline environments, they are deprotonated, thereby regulating the pH of the soil.

[0014] Bacillus pumilus is able to break down complex organic molecules into smaller ones by secreting a variety of enzymes, such as proteases, which break down proteins into amino acids, and cellulases, which break down cellulose into simple sugars.

[0015] Paenibacillus gelatinosa can solubilize phosphate and potassium, converting ineffective phosphorus and potassium fixed in the soil into available phosphorus and potassium that can be absorbed and utilized by plants, thereby improving the utilization rate of phosphorus and potassium. Paenibacillus gelatinosa can convert nitrogen in the air into its own bacterial proteins, thus enriching the soil.

[0016] Bacillus subtilis promotes the growth of plant roots and aerial parts by secreting plant hormones (such as auxins and gibberellins) and various enzymes (such as phytases and cellulases), enhancing plant resistance to stress. It also exhibits significant antimicrobial activity, inhibiting the growth of various plant pathogens. It also improves soil structure by fixing nitrogen and solubilizing phosphate and potassium, providing a more suitable growth environment for plants. Bacillus pumilus is widely used in agriculture to control plant diseases. It secretes antimicrobial substances (such as chitinase and lipopeptides) that inhibit the growth of plant pathogenic fungi. The polysaccharide capsule secreted by Bacillus gelatinosa produces a variety of antibiotics, inhibiting the growth of many harmful microorganisms.

[0017] Furthermore, the Bacillus are Bacillus subtilis and Bacillus pumilus with a live bacterial colony count ratio of 1:1.

[0018] Furthermore, the mass ratio of lotus root starch to trehalose is 2-3:1. Trehalose can serve as a stress protector for bacterial strains, maintaining their survival rate during the drying process. Lotus root starch contains starch, as well as rich iron, calcium, phosphorus, vitamins, and various minerals. It swells and gelatinizes when exposed to water, forming a viscous, translucent colloid. Compared to corn starch, it contains a higher proportion of amylopectin, and has a higher viscosity after gelatinization. It can be used with trehalose to encapsulate bacterial strains and serve as a slow-release carbon source to support the continued proliferation of microorganisms in the soil. The minerals in it can also compensate for the soil.

[0019] Furthermore, the bentonite is sodium bentonite with a particle size of ≤100 mesh.

[0020] Furthermore, the inorganic chelating agent is nano-hydroxyapatite. Hydroxyapatite (HAP), also known as basic calcium phosphate, is weakly alkaline and can adjust the pH of the soil. Nano-hydroxyapatite has a large adsorption capacity due to its high specific surface area and porous structure, and can achieve chelation adsorption of metals through processes such as chemical adsorption and ion exchange. Furthermore, the nano-hydroxyapatite is prepared using shells as raw materials.

[0021] The present invention also provides a method for preparing an agricultural soil conditioner, comprising the following steps: Step 1: Inoculate Bacillus, Alcaligenes xylosoxidans subsp. denitrificans and Alcaligenes faecalis into LB medium respectively and culture until ≥1 CFU / g, mixed according to the colony count ratio to form a composite microbial agent; Step 2: Mix the composite microbial inoculant with bentonite, add trehalose and gelatinized lotus root starch, and continue mixing until evenly mixed. Dry at room temperature to load the bacteria and obtain the loaded inoculant. The triple protection of bentonite, trehalose, and lotus root starch: bentonite adsorbs and immobilizes the bacteria, trehalose stabilizes the cell membrane, and lotus root starch provides a slow-release carbon source, significantly improving the survival rate of the inoculant during processing and in the soil environment.

[0022] Step 3: soybean meal, bagasse, rice husk ash, brewer's grains, tea residue, turmeric powder and inorganic chelating agent are mixed, crushed and sieved through 100 mesh, the sieved material and the loaded bacterial agent are mixed evenly, and the agricultural soil conditioner is obtained after being fully dried.

[0023] Furthermore, the gelatinized lotus root starch is prepared by dissolving lotus root starch in water, heating and gelatinizing, cooling to room temperature, wherein the concentration of lotus root starch in water is 5-10 wt %, and the heating temperature is 60-80 .

[0024] Beneficial effects of the present invention: (1) The improver provided by the present invention combines the alkalinity production of microorganisms with the chemical neutralization of rice husk ash to achieve a dual biological and chemical neutralization of acidity. It also utilizes a combination of bacteria with different functions to reduce the accumulation of nitrates and organic acids in the soil, dephosphorize and fix nitrogen, and achieve a synergistic effect of rapid improvement and long-term maintenance of soil pH.

[0025] (2) The raw materials used in the present invention have no pollution hazards and can avoid the microplastic risk of synthetic modifiers. The industrial and agricultural waste (bagasse, brewer's grains, tea residue, soybean meal, rice husk ash) can be turned into treasure. By optimizing the ratio, it can form good nutrients for microorganisms in the soil and improve the activity of microorganisms. It also combines waste materials from multiple industries to reduce costs.

[0026] (3) The microbial agent of the present invention can produce antibacterial substances to inhibit pathogenic bacteria. At the same time, turmeric powder contains natural antibacterial substances. Turmeric powder can be used as a fast-acting antibacterial agent. The microbial agent can inhibit harmful pathogenic bacteria for a long time, forming a dual antibacterial system. At the same time, it avoids the damage of chemical fungicides to beneficial bacteria and reduces dependence on pesticides.

[0027] (4) In the preparation process of the present invention, bentonite is used to load the composite microbial agent, and trehalose and lotus root starch are used to embed it simultaneously. While forming a protection for the bacterial strain, it can also form a structure that softens and disintegrates when it comes into contact with water. When applied, it can release the microbial strains when it comes into contact with water, and the release effect is good. DETAILED DESCRIPTION

[0028] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0029] Example 1

[0030] Prepare the raw materials according to the following mass ratio: 35 parts of soybean meal, 22 parts of bagasse, 20 parts of rice husk ash, 12 parts of brewer's grains, 12 parts of tea residues, 5 parts of lotus root starch, 10 parts of composite microbial agent, 5 parts of trehalose, 25 parts of sodium bentonite, 8 parts of turmeric powder, and 10 parts of nano-hydroxyapatite.

[0031] Preparation of agricultural soil conditioner: Step 1: Inoculate Bacillus subtilis, Bacillus pumilus, Alcaligenes xylosoxidans subsp. denitrificans and Alcaligenes faecalis into LB medium respectively and culture until ≥1 CFU / g, and mixed according to the ratio of viable bacterial colony count of 1:1:1.5:0.8 to form a composite microbial agent; Step 2: Dissolve lotus root starch in water at a concentration of 8 wt%, and heat to 70 After gelatinization and cooling to room temperature, the composite microbial agent and sodium bentonite (particle size ≤ 100 mesh) are mixed, trehalose and gelatinized lotus root starch are added and continued to be mixed evenly, and dried at room temperature to achieve strain loading to obtain a loaded agent.

[0032] Step 3: soybean meal, bagasse, rice husk ash, brewer's grains, tea residue, turmeric powder and nano-hydroxyapatite are mixed and crushed and sieved through 100 mesh, the sieved material and the loaded bacterial agent are mixed evenly, and the agricultural soil conditioner is obtained after being fully dried.

[0033] Example 2

[0034] The only difference from Example 1 is that the mass fraction of rice husk ash is adjusted to 18 parts, and the mass fraction of the composite microbial agent is adjusted to 9 parts.

[0035] Prepare the raw materials according to the following mass ratio: 35 parts of soybean meal, 22 parts of bagasse, 18 parts of rice husk ash, 12 parts of brewer's grains, 12 parts of tea residues, 5 parts of lotus root starch, 9 parts of composite microbial agent, 5 parts of trehalose, 25 parts of sodium bentonite, 8 parts of turmeric powder, and 10 parts of nano-hydroxyapatite.

[0036] Preparation of agricultural soil conditioner: Step 1: Inoculate Bacillus subtilis, Bacillus pumilus, Alcaligenes xylosoxidans subsp. denitrificans and Alcaligenes faecalis into LB medium respectively and culture until ≥1 CFU / g, and mixed according to the ratio of viable bacterial colony count of 1:1:1.5:0.8 to form a composite microbial agent; Step 2: Dissolve lotus root starch in water at a concentration of 8 wt%, and heat to 70 After gelatinization and cooling to room temperature, the composite microbial agent and sodium bentonite (particle size ≤ 100 mesh) are mixed, trehalose and gelatinized lotus root starch are added and continued to be mixed evenly, and dried at room temperature to achieve strain loading to obtain a loaded agent.

[0037] Step 3: soybean meal, bagasse, rice husk ash, brewer's grains, tea residue, turmeric powder and nano-hydroxyapatite are mixed and crushed and sieved through 100 mesh, the sieved material and the loaded bacterial agent are mixed evenly, and the agricultural soil conditioner is obtained after being fully dried.

[0038] Example 3

[0039] The only difference from Example 1 is that the mass fraction of rice husk ash is adjusted to 15 parts, and the mass fraction of the composite microbial agent is adjusted to 8 parts.

[0040] Prepare the raw materials according to the following mass ratio: 35 parts of soybean meal, 22 parts of bagasse, 15 parts of rice husk ash, 12 parts of brewer's grains, 12 parts of tea residues, 5 parts of lotus root starch, 8 parts of composite microbial agent, 5 parts of trehalose, 25 parts of sodium bentonite, 8 parts of turmeric powder, and 10 parts of nano-hydroxyapatite.

[0041] Preparation of agricultural soil conditioner: Step 1: Inoculate Bacillus subtilis, Bacillus pumilus, Alcaligenes xylosoxidans subsp. denitrificans and Alcaligenes faecalis into LB medium respectively and culture until ≥1 CFU / g, and mixed according to the ratio of viable bacterial colony count of 1:1:1.5:0.8 to form a composite microbial agent; Step 2: Dissolve lotus root starch in water at a concentration of 8 wt%, and heat to 70 After gelatinization and cooling to room temperature, the composite microbial agent and sodium bentonite (particle size ≤ 100 mesh) are mixed, trehalose and gelatinized lotus root starch are added and continued to be mixed evenly, and dried at room temperature to achieve strain loading to obtain a loaded agent.

[0042] Step 3: soybean meal, bagasse, rice husk ash, brewer's grains, tea residue, turmeric powder and nano-hydroxyapatite are mixed and crushed and sieved through 100 mesh, the sieved material and the loaded bacterial agent are mixed evenly, and the agricultural soil conditioner is obtained after being fully dried.

[0043] Example 4

[0044] The only difference from Example 2 is that the ratio of the number of viable bacteria of Bacillus subtilis, Bacillus pumilus, Alcaligenes xylosoxidans subsp. denitrificans, and Alcaligenes faecalis is adjusted to 1:1:1.4:0.9.

[0045] Prepare the raw materials according to the following mass ratio: 35 parts of soybean meal, 22 parts of bagasse, 18 parts of rice husk ash, 12 parts of brewer's grains, 12 parts of tea residues, 5 parts of lotus root starch, 9 parts of composite microbial agent, 5 parts of trehalose, 25 parts of sodium bentonite, 8 parts of turmeric powder, and 10 parts of nano-hydroxyapatite.

[0046] Preparation of agricultural soil conditioner: Step 1: Inoculate Bacillus subtilis, Bacillus pumilus, Alcaligenes xylosoxidans subsp. denitrificans and Alcaligenes faecalis into LB medium respectively and culture until ≥1 CFU / g, and mixed according to the ratio of viable bacterial colony count of 1:1:1.4:0.9 to form a composite microbial agent; Step 2: Dissolve lotus root starch in water at a concentration of 8 wt%, and heat to 70 After gelatinization and cooling to room temperature, the composite microbial agent and sodium bentonite (particle size ≤ 100 mesh) are mixed, trehalose and gelatinized lotus root starch are added and continued to be mixed evenly, and dried at room temperature to achieve strain loading to obtain a loaded agent.

[0047] Step 3: soybean meal, bagasse, rice husk ash, brewer's grains, tea residue, turmeric powder and nano-hydroxyapatite are mixed and crushed and sieved through 100 mesh, the sieved material and the loaded bacterial agent are mixed evenly, and the agricultural soil conditioner is obtained after being fully dried.

[0048] Example 5

[0049] The only difference from Example 2 is that the ratio of the number of viable bacteria of Bacillus subtilis, Bacillus pumilus, Alcaligenes xylosoxidans subsp. denitrificans, and Alcaligenes faecalis is adjusted to 1:1:1.2:1.

[0050] Prepare the raw materials according to the following mass ratio: 35 parts of soybean meal, 22 parts of bagasse, 18 parts of rice husk ash, 12 parts of brewer's grains, 12 parts of tea residues, 5 parts of lotus root starch, 9 parts of composite microbial agent, 5 parts of trehalose, 25 parts of sodium bentonite, 8 parts of turmeric powder, and 10 parts of nano-hydroxyapatite.

[0051] Preparation of agricultural soil conditioner: Step 1: Inoculate Bacillus subtilis, Bacillus pumilus, Alcaligenes xylosoxidans subsp. denitrificans and Alcaligenes faecalis into LB medium respectively and culture until ≥1 CFU / g, and mixed according to the ratio of viable bacterial colony count of 1:1:1.2:1 to form a composite microbial agent; Step 2: Dissolve lotus root starch in water at a concentration of 8 wt%, and heat to 70 After gelatinization and cooling to room temperature, the composite microbial agent and sodium bentonite (particle size ≤ 100 mesh) are mixed, trehalose and gelatinized lotus root starch are added and continued to be mixed evenly, and dried at room temperature to achieve strain loading to obtain a loaded agent.

[0052] Step 3: soybean meal, bagasse, rice husk ash, brewer's grains, tea residue, turmeric powder and nano-hydroxyapatite are mixed and crushed and sieved through 100 mesh, the sieved material and the loaded bacterial agent are mixed evenly, and the agricultural soil conditioner is obtained after being fully dried.

[0053] Example 6

[0054] The only difference from Example 4 is that the mass fraction of turmeric powder is adjusted to 7 parts.

[0055] Example 7

[0056] The only difference from Example 4 is that the mass fraction of turmeric powder is adjusted to 6 parts, and the other conditions and steps are the same as those in Example 4.

[0057] Example 8

[0058] The only difference from Example 1 is that the mass fraction of lotus root starch is adjusted to 10 parts and the mass fraction of trehalose is adjusted to 3 parts, and the other conditions and steps are the same as Example 1.

[0059] Example 9

[0060] The only difference from Example 1 is that the mass fraction of lotus root starch is adjusted to 15 parts and the mass fraction of trehalose is adjusted to 2 parts. Other conditions and steps are the same as Example 1.

[0061] Example 10

[0062] The only difference from Example 1 is that the number of nano-hydroxyapatite parts is adjusted to 8 parts, and the other conditions and steps are the same as Example 1.

[0063] Example 11

[0064] The only difference from Example 1 is that the number of nano-hydroxyapatite parts is adjusted to 5 parts, and the other conditions and steps are the same as Example 1.

[0065] Example 12

[0066] The only difference from Example 1 is that the bacterial species in the composite microbial inoculant is replaced by Bacillus subtilis with Bacillus gellingii, and the other conditions and steps are the same as those in Example 1.

[0067] Example 13

[0068] The only difference from Example 1 is that the bacterial species in the composite microbial inoculant is replaced by Bacillus jelly subtilis, and the other conditions and steps are the same as those in Example 1.

[0069] Comparative Example 1

[0070] The only difference from Example 1 is that Alcaligenes xylosoxidans subsp. denitrificans is not added to the composite microbial agent.

[0071] Prepare the raw materials according to the following mass ratio: 35 parts of soybean meal, 22 parts of bagasse, 20 parts of rice husk ash, 12 parts of brewer's grains, 12 parts of tea residues, 5 parts of lotus root starch, 10 parts of composite microbial agent, 5 parts of trehalose, 25 parts of sodium bentonite, 8 parts of turmeric powder, and 10 parts of nano-hydroxyapatite.

[0072] Preparation of agricultural soil conditioner: Step 1: Inoculate Bacillus subtilis, Bacillus pumilus and Alcaligenes faecalis into LB medium respectively and culture until ≥1 CFU / g, and mixed according to the ratio of viable bacterial colony count of 1:1:0.8 to form a composite microbial agent; Step 2: Dissolve lotus root starch in water at a concentration of 8 wt%, and heat to 70 After gelatinization and cooling to room temperature, the composite microbial agent and sodium bentonite (particle size ≤ 100 mesh) are mixed, trehalose and gelatinized lotus root starch are added and continued to be mixed evenly, and dried at room temperature to achieve strain loading to obtain a loaded agent.

[0073] Step 3: soybean meal, bagasse, rice husk ash, brewer's grains, tea residue, turmeric powder and nano-hydroxyapatite are mixed and crushed and sieved through 100 mesh, the sieved material and the loaded bacterial agent are mixed evenly, and the agricultural soil conditioner is obtained after being fully dried.

[0074] Comparative Example 2

[0075] The only difference from Example 1 is that no Bacillus is added to the composite microbial inoculant.

[0076] Prepare the raw materials according to the following mass ratio: 35 parts of soybean meal, 22 parts of bagasse, 20 parts of rice husk ash, 12 parts of brewer's grains, 12 parts of tea residues, 5 parts of lotus root starch, 10 parts of composite microbial agent, 5 parts of trehalose, 25 parts of sodium bentonite, 8 parts of turmeric powder, and 10 parts of nano-hydroxyapatite.

[0077] Preparation of agricultural soil conditioner: Step 1: Inoculate Alcaligenes xylosoxidans subsp. denitrificans and Alcaligenes faecalis into LB medium respectively and culture until ≥1 CFU / g, and mixed according to the ratio of viable bacterial colony count of 1.5:0.8 to form a composite microbial agent; Step 2: Dissolve lotus root starch in water at a concentration of 8 wt%, and heat to 70 After gelatinization and cooling to room temperature, the composite microbial agent and sodium bentonite (particle size ≤ 100 mesh) are mixed, trehalose and gelatinized lotus root starch are added and continued to be mixed evenly, and dried at room temperature to achieve strain loading to obtain a loaded agent.

[0078] Step 3: soybean meal, bagasse, rice husk ash, brewer's grains, tea residue, turmeric powder and nano-hydroxyapatite are mixed and crushed and sieved through 100 mesh, the sieved material and the loaded bacterial agent are mixed evenly, and the agricultural soil conditioner is obtained after being fully dried.

[0079] Comparative Example 3

[0080] The only difference from Example 1 is that the lotus root starch is replaced by trehalose of equal mass in the raw materials.

[0081] Prepare the raw materials according to the following mass ratio: 35 parts of soybean meal, 22 parts of bagasse, 20 parts of rice husk ash, 12 parts of brewer's grains, 12 parts of tea residues, 10 parts of composite microbial agent, 10 parts of trehalose, 25 parts of sodium bentonite, 8 parts of turmeric powder, and 10 parts of nano-hydroxyapatite.

[0082] Preparation of agricultural soil conditioner: Step 1: Inoculate Bacillus subtilis, Bacillus pumilus, Alcaligenes xylosoxidans subsp. denitrificans and Alcaligenes faecalis into LB medium respectively and culture until ≥1 CFU / g, and mixed according to the ratio of viable bacterial colony count of 1:1:1.5:0.8 to form a composite microbial agent; Step 2: Mix the composite microbial agent and sodium bentonite (particle size ≤ 100 mesh), add trehalose and continue to mix evenly, dry at room temperature to achieve bacterial loading, and obtain a loaded agent.

[0083] Step 3: soybean meal, bagasse, rice husk ash, brewer's grains, tea residue, turmeric powder and nano-hydroxyapatite are mixed and crushed and sieved through 100 mesh, the sieved material and the loaded bacterial agent are mixed evenly, and the agricultural soil conditioner is obtained after being fully dried.

[0084] Comparative Example 4

[0085] This comparative example uses lime as the acidic soil conditioner.

[0086] The soil conditioners prepared in Examples 1 to 13 and Comparative Examples 1 to 4 were subjected to field tests. A test field was selected and the soil pH value of the test field was tested. The pH value was 4.3. The soil conditioner was used to improve the soil at an application rate of 130 kg / mu. Rice was planted. A blank control group was set up. The soil conditioner was not applied to the soil in the blank control group. The changes in soil pH value and crop yield at different stages were tested. The results are shown in Table 1: Table 1

[0087] It can be seen from Table 1 that the rice yield after the soil conditioner prepared in the embodiment was applied to the soil was significantly higher than that of the comparative example. Among them, in Examples 1 to 3, the ratio of rice husk ash and composite microbial agent in Example 2 was the best. Although excessive application of rice husk ash increased the pH of the soil, The changes are obvious, but the organic matter in the rice husk ash has been converted into carbon black, which will reduce the nutrients of the microorganisms in the soil conditioner. The proportion of rice husk ash is low, and the amplitude of the rapid increase in soil pH is reduced. The ratio of various strains of the composite microbial inoculant is optimized and adjusted. Under the conditions of Example 4, Xylosoxidans Alcaligenes denitrificans subspecies and Alcaligenes faecalis can work synergistically to maximize the long-term regulation of soil pH. Compared with Example 4, Examples 6 and 7 reduce the content of turmeric powder. The content of turmeric powder has no significant effect on the overall soil pH, but it will affect the health of the crops. The turmeric powder and the antibacterial substances produced by microorganisms in the soil conditioner prepared in Example 6 work together to increase yield. In Examples 8 and 9, the ratio of lotus root starch and trehalose affects the survival rate of the strains of the composite microbial inoculant, indirectly affecting the pH regulation effect and yield. In Examples 12 and 13, the combination of strains was adjusted. In Example 12, the combination of Bacillus mucilaginosus and Bacillus pumilus significantly increased the yield of crops.

[0088] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0089] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. An agricultural soil conditioner, characterized in that Calculated by mass, it includes the following raw materials: 30-40 parts of soybean meal, 20-25 parts of bagasse, 15-20 parts of rice husk ash, 5-15 parts of brewer's grains, 6-12 parts of tea residue, 5-15 parts of lotus root starch, 8-10 parts of composite microbial agent, 2-5 parts of trehalose, 15-25 parts of bentonite, 6-8 parts of turmeric powder, and 5-10 parts of inorganic chelating agent; The composite microbial agent comprises Bacillus, Alcaligenes xylosoxidans subspecies denitrificans and Alcaligenes faecalis.

2. An agricultural soil conditioner according to claim 1, characterized in that The ratio of the number of live bacteria colonies of Bacillus, Alcaligenes xylosoxidans denitrificans subspecies and Alcaligenes faecalis in the composite microbial agent is 2:1.2-1.5:0.8-1.

3. The agricultural soil conditioner according to claim 1, characterized in that The Bacillus is at least one of Bacillus subtilis, Bacillus pumilus and Paenibacillus jelly.

4. The agricultural soil conditioner according to claim 1, characterized in that The bacillus are Bacillus subtilis and Bacillus pumilus with a live bacterial colony count ratio of 1:

1.

5. The agricultural soil conditioner according to claim 1, characterized in that: The mass ratio of the lotus root starch to trehalose is 2-3:

1.

6. The agricultural soil conditioner according to claim 1, characterized in that: The bentonite is sodium bentonite with a particle size of ≤100 mesh.

7. The agricultural soil conditioner according to claim 1, characterized in that: The inorganic chelating agent is nano-hydroxyapatite.

8. The agricultural soil conditioner according to claim 7, characterized in that: The nano hydroxyapatite is prepared by using shells as raw materials.

9. A method for preparing the agricultural soil conditioner according to any one of claims 1 to 8, characterized in that: The following steps are involved: Step 1: Inoculate Bacillus, Alcaligenes xylosoxidans subsp. denitrificans and Alcaligenes faecalis into LB medium respectively and culture until ≥1 CFU / g, mixed according to the colony count ratio to form a composite microbial agent; Step 2: Mix the composite microbial agent and bentonite, add trehalose and gelatinized lotus root starch, continue to mix evenly, and dry at room temperature to achieve bacterial loading to obtain a loaded agent; Step 3: soybean meal, bagasse, rice husk ash, brewer's grains, tea residue, turmeric powder and inorganic chelating agent are mixed, crushed and sieved through 100 mesh, the sieved material and the loaded bacterial agent are mixed evenly, and the agricultural soil conditioner is obtained after being fully dried.

10. The method for preparing an agricultural soil conditioner according to claim 9, characterized in that: The gelatinized lotus root starch is prepared by dissolving the lotus root starch in water, heating and gelatinizing, and cooling to room temperature. The concentration of the lotus root starch in the water is 5-10 wt %, and the heating temperature is 60-80 .

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