Microbial agent for increasing available phosphorus in alkaline soil and application thereof

Abstract

The invention discloses a microbial agent for increasing available phosphorus in alkaline soil and application of the microbial agent, and belongs to the technical field of microbial agents and soil modification. The microbial agent for increasing the available phosphorus in the alkaline soil is prepared by taking the microbial compound bacterium powder, the adsorbent and the acid conditioner as raw materials, and the microbial compound bacterium powder can convert insoluble phosphorus in the soil into the available phosphorus which can be absorbed by crops, so that the content of the available phosphorus in the soil is increased; the improvement of crop yield and quality is promoted; on one hand, the adsorbent can adsorb microorganisms to avoid non-uniform distribution of available phosphorus capable of being utilized by plants in soil due to non-uniform application of a fungicide and the like, and on the other hand, the adsorbent can provide a good condition for propagation of the microorganisms to give full play to the conversion effect of the microorganisms; and the acid conditioner and the microbial compound bacterium powder cooperate to condition the soil, so that the alkaline soil has a more lasting conditioning effect, and the alkaline soil is thoroughly improved for a long time.

Description

Technical Field

[0001] The invention belongs to the technical field of microbial agents and soil modification, and in particular relates to a microbial agent for increasing available phosphorus in alkaline soil and application thereof. Background Art

[0002] Alkaline soil includes saline soil, salinized soil, alkaline soil and alkalized soil, which are formed and developed under certain environmental conditions. Alkaline soil has a high salt content, coexistence of drought and waterlogging, low organic matter content, poor soil physical and chemical properties, poor buffering performance, low water and fertilizer retention capacity, many anions and cations that are harmful to crop growth, which is not conducive to the growth and development of crops, and low land productivity and carrying capacity. The most common way to improve alkaline soil is to apply soil conditioners. However, most of the existing conditioners only rely on neutralizing the alkaline substances in alkaline soil to achieve the purpose of improving the soil. This method can only improve the soil for a period of time, cannot achieve long-term improvement, and the improvement of soil alkalinity is not thorough.

[0003] Phosphorus is the main nutrient element for plant growth. It mainly exists in the form of insoluble minerals in the soil. Therefore, the utilization rate of phosphorus in the soil by plants is very low, which seriously affects the growth of crops. From the perspective of my country, 74% of the cultivated land in the country is phosphorus-deficient. In the prior art, two methods are usually adopted to solve the problem of soil phosphorus deficiency: increasing phosphorus source input and improving the utilization rate of insoluble phosphorus. However, phosphorus is a non-renewable resource, and excessive use of phosphorus fertilizers for high yield will lead to a large amount of phosphorus enrichment in the soil, which will not only cause unnecessary waste, but also affect the absorption of other nutrients by crops, and also lead to eutrophication of water bodies and damage the ecological environment. Therefore, the method of increasing phosphorus source input is not a long-term solution. Phosphate-solubilizing bacteria can convert insoluble phosphorus into effective phosphorus through the effects of phosphorus dissolution, phosphorus uptake, and complexation, thereby improving the utilization rate of insoluble phosphorus in the soil. However, due to the uneven application of bacterial agents and other reasons, the effective phosphorus that can be used by plants in the soil is unevenly distributed, and plant absorption and utilization are limited.

[0004] Therefore, how to provide a conditioner that can improve the alkaline soil environment for a long time while increasing the utilization rate of insoluble phosphorus in the soil has become a technical problem that technical personnel in this field urgently need to solve. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a microbial agent for increasing available phosphorus in alkaline soil and its application.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] The invention provides a microbial agent for increasing available phosphorus in alkaline soil. The microbial agent comprises the following components in parts by weight: 20 to 40 parts of microbial composite powder, 50 to 70 parts of an adsorbent and 15 to 25 parts of an acidic conditioner.

[0008] Preferably, the microbial agent comprises the following components in parts by weight: 25-35 parts of composite microbial powder, 55-65 parts of adsorbent and 20-25 parts of acidic conditioner.

[0009] Preferably, the composite microbial powder consists of Bacillus megaterium powder, arbuscular mycorrhizal fungi powder and Bacillus subtilis powder.

[0010] Preferably, the mass ratio of the Bacillus megaterium powder, the arbuscular mycorrhizal fungi powder and the Bacillus subtilis powder is (3-6):(2-3):(2-4).

[0011] Preferably, the adsorbent comprises crop straw biochar, polysaccharide and vegetable oil.

[0012] Preferably, the method for preparing the crop straw biochar comprises the following steps: crushing the crop straw and mixing it with water, and then carbonizing it at 440-460° C. for 1-2 hours to obtain the crop straw biochar.

[0013] Preferably, the acidic conditioning agent includes maleic anhydride, maleic acid, tartaric acid, pyrophosphoric acid and salicylic acid.

[0014] Preferably, the weight ratio of maleic anhydride, maleic acid, tartaric acid, pyrophosphoric acid and salicylic acid is (35-38):(2-3):(5-7):(8-10):(2-3).

[0015] The present invention provides a method for preparing the microbial agent for increasing the available phosphorus in alkaline soil described in the above technical scheme, comprising the following steps: weighing each raw material according to weight, adsorbing and mixing the microbial composite powder and the adsorbent in reclaimed water, then adding an acidic conditioner and mixing evenly, and drying to obtain the microbial agent for increasing the available phosphorus in alkaline soil.

[0016] The present invention also provides the use of the microbial agent for increasing available phosphorus in alkaline soil described in the above technical solution in improving alkaline soil.

[0017] Compared with the prior art, the present invention has the following advantages and technical effects:

[0018] The present invention uses microbial composite bacterial powder, adsorbent and acidic conditioning agent as raw materials to prepare a microbial agent for increasing effective phosphorus in alkaline soil, wherein the microbial composite bacterial powder can convert insoluble phosphorus in the soil into effective phosphorus that can be absorbed by crops, thereby increasing the effective phosphorus content in the soil and promoting the improvement of crop yield and quality; the adsorbent can adsorb microorganisms on the one hand to avoid uneven distribution of effective phosphorus that can be used by plants in the soil due to uneven application of the bacterial agent, and on the other hand can also provide good conditions for the reproduction of microorganisms and give full play to the conversion effect of the microorganisms; the acidic conditioning agent and the microbial composite bacterial powder cooperate to condition the soil, so that the alkaline soil obtains a more lasting conditioning effect, thereby achieving long-term and thorough improvement of the alkaline soil. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below in conjunction with specific implementation methods.

[0021] The embodiment of the present invention provides a microbial agent for increasing available phosphorus in alkaline soil. The microbial agent comprises the following raw materials in parts by weight: 20 to 40 parts of microbial composite powder, 50 to 70 parts of an adsorbent, and 15 to 25 parts of an acid conditioner.

[0022] The microbial composite powder in the present invention can convert the insoluble phosphorus in the soil into effective phosphorus that can be absorbed by crops, thereby increasing the effective phosphorus content in the soil and promoting the improvement of crop yield and quality; the adsorbent can adsorb microorganisms on the one hand to avoid uneven distribution of effective phosphorus that can be used by plants in the soil due to uneven application of the microbial agent, and on the other hand can also provide good conditions for the reproduction of microorganisms and give full play to the conversion effect of the microorganisms; the acidic conditioner and the microbial composite powder synergistically condition the soil, so that the alkaline soil obtains a more lasting conditioning effect, thereby achieving long-term and thorough improvement of the alkaline soil.

[0023] In a preferred embodiment, the microbial agent for increasing available phosphorus in alkaline soil comprises 20 to 40 parts by weight of composite microbial powder, preferably 25 to 35 parts by weight.

[0024] In a preferred embodiment, the microbial composite powder is composed of Bacillus megaterium powder, arbuscular mycorrhizal fungi powder and Bacillus subtilis powder. Bacillus megaterium and Bacillus subtilis in the present invention can promote the dissolution of insoluble phosphorus in the soil, thereby increasing the content of effective phosphorus in the soil, and arbuscular mycorrhizal fungi can increase the absorption range and ability of crops to phosphorus in the soil through their hyphae network, and can also promote the decomposition and utilization of organic phosphorus through the enzyme substances secreted by them; in addition, arbuscular mycorrhizal fungi can improve the soil structure, provide a better growth environment for Bacillus megaterium and Bacillus subtilis, and the metabolites of Bacillus megaterium and Bacillus subtilis can promote the growth and reproduction of arbuscular mycorrhizal fungi, jointly promote the effectiveness of phosphorus in the soil, and then maximize the conversion of insoluble phosphorus in the soil into effective phosphorus that can be used by crops.

[0025] In a preferred embodiment, the mass ratio of the Bacillus megaterium powder, the arbuscular mycorrhizal fungi powder and the Bacillus subtilis powder is (3-6):(2-3):(2-4).

[0026] In a preferred embodiment, the effective viable bacteria count of Bacillus megaterium in the Bacillus megaterium powder is at least 1.0×10 10 CFU / g; the effective viable number of arbuscular mycorrhizal fungi in the arbuscular mycorrhizal fungi powder is at least 1.0×10 9 CFU / g; the effective viable bacteria count of Bacillus subtilis in the Bacillus subtilis powder is at least 1.0×10 10 CFU / g.

[0027] In a preferred embodiment, the microbial agent for increasing available phosphorus in alkaline soil includes 50 to 70 parts of adsorbent, preferably 55 to 65 parts by weight.

[0028] In a preferred embodiment, the adsorbent includes crop straw biochar, polysaccharide and vegetable oil. The present invention uses crop straw biochar, polysaccharide and vegetable oil to make an adsorbent, which can adsorb microorganisms and provide good conditions for the reproduction of microorganisms, giving full play to the transformation effect of microorganisms.

[0029] In a preferred embodiment, the mass ratio of the crop straw biochar, polysaccharide and vegetable oil is (8-10):(2-4):(2-3).

[0030] In a preferred embodiment, the method for preparing the crop straw biochar comprises the following steps: crushing the crop straw and mixing it with water, and then carbonizing it at 440-460° C. for 1-2 hours to obtain the crop straw biochar.

[0031] In a preferred embodiment, the crop straw includes one or more of corn straw and wheat straw.

[0032] In a preferred embodiment, the mass ratio of the crop straw to water is 1:(2-3).

[0033] In a preferred embodiment, the polysaccharide includes one or more of starch, chitosan, and agar.

[0034] In a preferred embodiment, the vegetable oil includes one or more of soybean oil, peanut oil, corn oil, and sesame oil.

[0035] In a preferred embodiment, the microbial agent for increasing available phosphorus in alkaline soil includes 15 to 25 parts, preferably 20 to 25 parts, of an acid conditioner by weight.

[0036] In a preferred embodiment, the acidic conditioner includes maleic anhydride, maleic acid, tartaric acid, pyrophosphoric acid and salicylic acid. The acidic conditioner in the present invention cooperates with the microbial composite powder to condition the soil, improve the physical and chemical properties of alkaline soil, and increase soil productivity.

[0037] In a preferred embodiment, the weight ratio of maleic anhydride, maleic acid, tartaric acid, pyrophosphoric acid and salicylic acid is (35-38):(2-3):(5-7):(8-10):(2-3). Maleic anhydride and maleic acid in the present invention can react with alkaline substances in the soil to reduce the pH value of the soil and improve the pH value of the soil; pyrophosphoric acid can promote the coagulation and stability of soil particles and improve the soil structure; tartaric acid and salicylic acid can form complexes with metal ions in the soil to increase the effectiveness of nutrients in the soil; the combined action of several substances improves the physical and chemical properties and biological activity of alkaline soil, increases the effectiveness of nutrients in the soil, and thus increases the productivity of the soil.

[0038] The present invention provides a method for preparing the microbial agent for increasing the available phosphorus in alkaline soil described in the above technical scheme, comprising the following steps: weighing each raw material according to weight, adsorbing and mixing the microbial composite powder and the adsorbent in reclaimed water, then adding an acidic conditioner and mixing evenly, and drying to obtain the microbial agent for increasing the available phosphorus in alkaline soil.

[0039] In a preferred embodiment, the drying temperature is 35-40° C. and the drying time is 12-24 hours.

[0040] The present invention also provides the use of the microbial agent for increasing available phosphorus in alkaline soil described in the above technical solution in improving alkaline soil.

[0041] In a preferred embodiment, the amount of the microbial agent for increasing the available phosphorus in alkaline soil applied to the alkaline soil is 20 to 30 kg / mu.

[0042] Unless otherwise specified, parts in the embodiments of the present invention represent “parts by weight”.

[0043] In the following examples and comparative examples, Bacillus megaterium powder was purchased from Hubei Xinghengye Technology Co., Ltd., and the effective viable count of Bacillus megaterium in the Bacillus megaterium powder was 20 billion CFU / g; arbuscular mycorrhizal fungi powder was purchased from Yangzhou Herrenknecht Biotechnology Co., Ltd., and the effective viable count of arbuscular mycorrhizal fungi in the arbuscular mycorrhizal fungi powder was 10 billion CFU / g; Bacillus subtilis powder was purchased from Shandong Xinzhuoyuan Biotechnology Co., Ltd., and the effective viable count of Bacillus subtilis in the Bacillus subtilis powder was 20 billion CFU / g.

[0044] Unless otherwise specified, the raw materials in the examples of the present invention were purchased from commercial sources.

[0045] Example 1

[0046] A microbial agent for increasing available phosphorus in alkaline soil, the specific preparation process is as follows:

[0047] (1) Preparation of microbial composite powder: 4 parts of Bacillus megaterium powder, 2 parts of arbuscular mycorrhizal fungi powder and 3 parts of Bacillus subtilis powder were mixed evenly to obtain microbial composite powder.

[0048] (2) Preparation of adsorbent: Grind corn straw and mix it with water in a mass ratio of 1:3, and then carbonize it at 460°C for 1 h to obtain corn straw biochar; take 8 parts of corn straw biochar, 2 parts of starch and 3 parts of soybean oil, mix them evenly, and then dry them at 35°C for 12 h to obtain the adsorbent.

[0049] (3) Preparation of an acidic conditioner: 35 parts of maleic anhydride, 3 parts of maleic acid, 6 parts of tartaric acid, 10 parts of pyrophosphoric acid and 2 parts of salicylic acid are mixed uniformly to obtain an acidic conditioner.

[0050] (4) Preparation of a microbial agent for increasing the available phosphorus in alkaline soil: 25 parts of the microbial composite powder in step (1) and 55 parts of the adsorbent in step (2) are placed in water for adsorption and mixing, and then 20 parts of the acidic conditioner in step (3) are added and mixed evenly, and dried at 35° C. for 20 hours to obtain a microbial agent for increasing the available phosphorus in alkaline soil.

[0051] Example 2

[0052] A microbial agent for increasing available phosphorus in alkaline soil, the specific preparation process is as follows:

[0053] (1) Preparation of composite microbial powder: 6 parts of Bacillus megaterium powder, 3 parts of arbuscular mycorrhizal fungi powder and 4 parts of Bacillus subtilis powder were mixed uniformly to obtain composite microbial powder.

[0054] (2) Preparation of adsorbent: Grind corn straw and mix it with water in a mass ratio of 1:3, and then carbonize it at 460°C for 1 h to obtain corn straw biochar; take 9 parts of corn straw biochar, 4 parts of chitosan and 3 parts of sesame oil, mix them evenly, and then dry them at 35°C for 12 h to obtain the adsorbent.

[0055] (3) Preparation of an acidic conditioner: 36 parts of maleic anhydride, 3 parts of maleic acid, 5 parts of tartaric acid, 8 parts of pyrophosphoric acid and 2 parts of salicylic acid are mixed uniformly to obtain an acidic conditioner.

[0056] (4) Preparation of a microbial agent for increasing the available phosphorus in alkaline soil: 40 parts of the microbial composite powder in step (1) and 60 parts of the adsorbent in step (2) are placed in water for adsorption and mixing, and then 15 parts of the acidic conditioner in step (3) are added and mixed evenly, and dried at 35° C. for 20 hours to obtain a microbial agent for increasing the available phosphorus in alkaline soil.

[0057] Example 3

[0058] A microbial agent for increasing available phosphorus in alkaline soil, the specific preparation process is as follows:

[0059] (1) Preparation of microbial composite powder: 5 parts of Bacillus megaterium powder, 2 parts of arbuscular mycorrhizal fungi powder and 4 parts of Bacillus subtilis powder were mixed evenly to obtain microbial composite powder.

[0060] (2) Preparation of adsorbent: Crush wheat straw and mix it with water in a mass ratio of 1:2, and then carbonize it at 450°C for 2 h to obtain wheat straw biochar; take 10 parts of wheat straw biochar, 3 parts of agar and 3 parts of peanut oil, mix them evenly, and then dry them at 35°C for 12 h to obtain the adsorbent.

[0061] (3) Preparation of an acidic conditioner: 38 parts of maleic anhydride, 2 parts of maleic acid, 7 parts of tartaric acid, 9 parts of pyrophosphoric acid and 3 parts of salicylic acid are mixed uniformly to obtain an acidic conditioner.

[0062] (4) Preparation of a microbial agent for increasing the available phosphorus in alkaline soil: 30 parts of the microbial composite powder in step (1) and 65 parts of the adsorbent in step (2) are placed in water for adsorption and mixing, and then 15 parts of the acidic conditioner in step (3) are added and mixed evenly, and dried at 35° C. for 20 hours to obtain a microbial agent for increasing the available phosphorus in alkaline soil.

[0063] Comparative Example 1

[0064] A microbial agent for increasing available phosphorus in alkaline soil, the specific preparation process is as follows:

[0065] Steps (1) to (2) are the same as in Example 1;

[0066] (3) Preparation of a microbial agent for increasing the available phosphorus in alkaline soil: 25 parts of the microbial composite powder in step (1) and 55 parts of the adsorbent in step (2) are placed in water for adsorption and mixing, and dried at 35° C. for 20 hours to obtain a microbial agent for increasing the available phosphorus in alkaline soil.

[0067] Comparative Example 2

[0068] A microbial agent for increasing available phosphorus in alkaline soil, the specific preparation process is as follows:

[0069] Step (1) is the same as step (1) of Example 1; Step (2) is the same as step (3) of Example 1;

[0070] (3) Preparation of a microbial agent for increasing the available phosphorus in alkaline soil: 25 parts of the microbial composite powder in step (1) and 20 parts of the acidic conditioner in step (2) are mixed evenly, and dried at 35° C. for 20 hours to obtain a microbial agent for increasing the available phosphorus in alkaline soil.

[0071] Comparative Example 3

[0072] The process for preparing the microbial agent for increasing the available phosphorus in alkaline soil is the same as that in Example 1, except that, in step (4), 10 parts of the microbial composite powder in step (1) and 55 parts of the adsorbent in step (2) are placed in water for adsorption and mixing, and then 20 parts of the acidic conditioner in step (3) are added and mixed evenly, and dried at 35° C. for 20 hours to obtain the microbial agent for increasing the available phosphorus in alkaline soil.

[0073] Comparative Example 4

[0074] The process for preparing the microbial agent for increasing the available phosphorus in alkaline soil is the same as that in Example 1, except that in step (1), 4 parts of Bacillus megaterium powder and 3 parts of Bacillus subtilis powder are taken and mixed evenly to obtain a microbial composite powder.

[0075] Comparative Example 5

[0076] The process for preparing the microbial agent for increasing available phosphorus in alkaline soil is the same as that in Example 1, except that, in step (1), 4 parts of Bacillus megaterium powder and 2 parts of arbuscular mycorrhizal fungi powder are taken and mixed evenly to obtain a microbial composite powder.

[0077] Comparative Example 6

[0078] The process for preparing the microbial agent for increasing the available phosphorus in alkaline soil is the same as that in Example 1, except that in step (3), 56 parts of maleic anhydride are taken as the acidic conditioner.

[0079] Field trials

[0080] An alkaline land was selected in the experimental farm of Ningxia University for the test, and the pH value of the alkaline land was measured to be 8.08. After the alkaline land was prepared and deep plowed, corn seeds were sown, and field management was carried out in a conventional manner. When the corn grew to the seedling stage, the microbial agents for increasing the available phosphorus in the alkaline soil in Examples 1 to 3 and Comparative Examples 1 to 6 were applied at an application amount of 20 kg / mu. During the growth of corn, the changes in the total phosphorus content in the corn field soil were monitored, and the sampling depth was 5 cm. The results are shown in Table 1. At the same time, the growth of corn was statistically analyzed, and the results are shown in Table 2. After the corn was harvested and threshed, the yield of corn was statistically analyzed, and the pH value of each group of experimental fields was tested, and the results are shown in Table 2.

[0081] Table 1 Changes in available phosphorus in corn fields in each treatment group

[0082]

[0083] Note: The blank group did not contain any microbial agents.

[0084] As can be seen from Table 1, when the microbial agent for increasing available phosphorus in alkaline soil prepared in Examples 1-3 of the present invention was applied to the corn field, the total phosphorus content in the corn field soil was significantly reduced compared to the application of the agent in Comparative Examples 1-6 and the blank group, indicating that the microbial agent for increasing available phosphorus in alkaline soil provided by the present invention can improve the utilization rate of insoluble phosphorus in the soil.

[0085] Table 2 Growth, yield and pH value of corn in each treatment group

[0086]

[0087] Note: The blank group did not contain any microbial agents.

[0088] As can be seen from Table 2, when the microbial agent for increasing the available phosphorus in alkaline soil prepared in Examples 1-3 of the present invention was applied in the corn field, the height of the corn plants was significantly improved compared with the application of the agent in Comparative Examples 1-6 and the blank group, and ultimately a higher yield and better benefits were achieved; at the same time, the application of the microbial agent for increasing the available phosphorus in alkaline soil prepared by the present invention can effectively regulate the alkaline soil, reduce the soil pH value, achieve long-term and thorough improvement of the alkaline soil, and meet the growth needs of crops.

[0089] The above are only preferred specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A microbial agent for increasing available phosphorus in alkaline soil, characterized in that: The microbial agent comprises the following components in parts by weight: 20 to 40 parts of composite microbial powder, 50 to 70 parts of adsorbent and 15 to 25 parts of acidic conditioner.

2. The microbial agent for increasing available phosphorus in alkaline soil according to claim 1, characterized in that: The microbial agent comprises the following components in parts by weight: 25-35 parts of composite microbial powder, 55-65 parts of adsorbent and 20-25 parts of acidic conditioner.

3. The microbial agent for increasing available phosphorus in alkaline soil according to claim 1 or 2, characterized in that: The microbial composite powder consists of Bacillus megaterium powder, arbuscular mycorrhizal fungi powder and Bacillus subtilis powder.

4. The microbial agent for increasing available phosphorus in alkaline soil according to claim 3, characterized in that: The mass ratio of the Bacillus megaterium powder, the arbuscular mycorrhizal fungus powder and the Bacillus subtilis powder is (3-6):(2-3):(2-4).

5. The microbial agent for increasing available phosphorus in alkaline soil according to claim 1 or 2, characterized in that: The adsorbent includes crop straw biochar, polysaccharide and vegetable oil.

6. The microbial agent for increasing available phosphorus in alkaline soil according to claim 5, characterized in that: The method for preparing the crop straw biochar comprises the following steps: crushing the crop straw and mixing it with water, and then carbonizing it at 440-460° C. for 1-2 hours to obtain the crop straw biochar.

7. The microbial agent for increasing available phosphorus in alkaline soil according to claim 1 or 2, characterized in that: Such acidic conditioning agents include maleic anhydride, maleic acid, tartaric acid, pyrophosphoric acid and salicylic acid.

8. The microbial agent for increasing available phosphorus in alkaline soil according to claim 7, characterized in that: The weight ratio of maleic anhydride, maleic acid, tartaric acid, pyrophosphoric acid and salicylic acid is (35-38):(2-3):(5-7):(8-10):(2-3).

9. The method for preparing the microbial agent for increasing available phosphorus in alkaline soil according to any one of claims 1 to 8, characterized in that: The following steps are involved: The raw materials are weighed according to their weight proportions, the composite microbial powder and the adsorbent are adsorbed and mixed in medium water, and then an acidic conditioner is added and mixed evenly, and the mixture is dried to obtain the microbial agent for increasing the available phosphorus in alkaline soil.

10. Use of the microbial agent for increasing available phosphorus in alkaline soil according to any one of claims 1 to 8 in improving alkaline soil.

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