Saline-alkali soil conditioner rich in salt-tolerant microorganisms as well as preparation method and application of saline-alkali soil conditioner

Abstract

The invention relates to the technical field of soil improvement, in particular to a saline-alkali soil conditioner rich in salt-tolerant microorganisms and a preparation method and application of the saline-alkali soil conditioner rich in salt-tolerant microorganisms. The fertilizer is prepared from the following raw materials in parts by weight: 0.1-0.3 part of a microbial complex inoculant, 10-15 parts of potassium fulvate, 2-3 parts of a trace element composition, 1-3 parts of vitamin B, 20-30 parts of an organic fertilizer, 10-30 parts of modified medical stone and 2-4 parts of a copolymer. The soil conditioner prepared by the invention has good saline-alkaline resistance and can promote the growth of crops.

Description

Technical Field

[0001] The invention relates to the technical field of soil improvement, and in particular to a saline-alkali soil improver rich in salt-tolerant microorganisms, a preparation method and application thereof. Background Art

[0002] my country's saline-alkali land is mainly distributed in the northwest, north China and northeast China. The essence of the formation of saline-alkali land is mainly the horizontal and vertical redistribution of various soluble salts on the ground, so that salt gradually accumulates on the soil surface in the salt-collecting area. The high concentration of salt and alkaline substances in saline-alkali land makes it difficult for vegetation to grow and survive, affecting agricultural production. In addition, the existence of saline-alkali land leads to large-scale degradation of forests and grasslands, aggravates the greenhouse effect, and damages the ecological environment. Moreover, the saline-alkali land contains a large amount of chloride ions and sulfate ions, which will corrode buildings, causing the foundation bearing capacity to be severely weakened and there is a risk of dumping. Therefore, the research and development of saline-alkali land improvers is of great significance.

[0003] Patent CN103351870B discloses a soil conditioner, which includes the following components: acrylamide-acrylate copolymer crosslinked product, acrylamide-sodium acrylic acid copolymer, montmorillonite, and is formed by chelating the components. The soil conditioner is a light yellow powder particle, which is mixed with soil to form a very loose aggregate structure soil after agglomeration reaction and hydrophobic reaction. The aggregate structure soil has an excellent solid-liquid-gas three-phase structure of fertilizer retention, water retention, and air permeability, which is greatly beneficial to the growth of plant roots.

[0004] Patent CN105062496B discloses a soil conditioner, which is composed of the following weight percentage components: trace element composition 5-10%, disodium hydrogen phosphate 5-15%, fly ash 30-50%, bamboo powder 12-25%, sodium octaborate tetrahydrate 5-15%, and magnesium sugar alcohol 10-20%. The soil conditioner can reduce the use of fungicides when used for planting plants, quickly improve the soil pH value; increase the organic matter content of the soil, and bamboo powder can be continuously converted into humic acid under the action of trace element composition and magnesium sugar alcohol, continuously improving the soil aggregate structure; promote the growth of garden plants and improve the absorption of toxic metals in the soil by garden plants.

[0005] Most of the above patents use chemical improvement methods to improve the soil, but chemical improvers may have an impact on the ecological environment or cause secondary pollution. Therefore, a soil modifier that reduces the use of chemicals is urgently needed. Summary of the invention

[0006] In view of the problems existing in the prior art, the purpose of the present invention is to obtain a soil conditioner suitable for saline-alkali land, which can promote the growth of crops and reduce the use of chemical conditioners.

[0007] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] On the one hand, the present invention provides a saline-alkali soil conditioner rich in salt-tolerant microorganisms, which, by weight, comprises the following raw materials: 0.1-0.3 parts of a microbial complex bactericide, 10-15 parts of potassium humate, 2-3 parts of a trace element compound, 2-3 parts of vitamin B, 20-30 parts of organic fertilizer, 10-30 parts of modified picrite, and 2-4 parts of a copolymer.

[0009] In some embodiments, the preparation method of the copolymer comprises the following steps:

[0010] (1) Allyl chloride and sodium N-methyltaurate are added to DMF and reacted at 75-85°C for 6-7 h, and then dried to obtain an intermediate.

[0011] (2) The intermediate, lignosulfonate, and initiator obtained in step (1) are respectively added to deionized water and stirred at 40-50°C for 30-40 min to obtain an intermediate aqueous solution, a lignosulfonate aqueous solution, and an initiator aqueous solution respectively. Then, under a nitrogen atmosphere, the temperature is raised to 45-55°C, and the initiator aqueous solution and the intermediate aqueous solution are added dropwise to the lignosulfonate aqueous solution. Then, the temperature is raised to 75-85°C and reacted for 1.5-2.5 h. Then, an ethanol solution of resveratrol oxide is added and the reaction is continued for 0.5-1.5 h. After filtration, washing, and drying, the copolymer is obtained.

[0012] Saline-alkali land has poor water retention and low soil fertility, which affects the growth of plants and leads to low crop yields. The present invention first obtains an intermediate containing tertiary amine and sodium sulfonate from allyl chloride and sodium N-methyltaurate, and then reacts with lignosulfonate and then with resveratrol oxide to obtain a copolymer, which can effectively increase the water retention and air permeability of the soil and reduce the damage of saline-alkali land to plants. The possible reason is that there are many hydrophilic groups such as sulfonate groups and tertiary amines on the copolymer, which enhances the water retention capacity of the soil. At the same time, it has multiple benzene ring structures with large steric hindrance, increasing the air permeability of the soil. In addition, the added phenolic hydroxyl structure avoids the problem that the lignosulfonate chain segment is easily broken under light conditions, resulting in a decline in the use effect. In addition, in the soil, lignosulfonate can be degraded by microorganisms to generate humic acid, further improving the soil permeability and the utilization rate of fertilizers.

[0013] In some embodiments, the mass ratio of allyl chloride to sodium N-methyltaurate is (0.4-0.6):1.

[0014] In some embodiments, the mass ratio of the intermediate, lignosulfonate, and resveratrol oxide in step (2) is (0.2-0.6):1:(0.2-0.5).

[0015] By defining the mass ratio of allyl chloride to sodium N-methyltaurinate, the hydrogen atoms on the nitrogen in sodium N-methyltaurinate are more completely substituted, increasing the yield of the intermediate. Additionally, by defining the mass ratio of the intermediate, lignosulfonate, and resveratrol oxide, the copolymer can increase the air permeability of the soil while having good water retention.

[0016] In some embodiments, the microbial complex agent is a composition of Bacillus amyloliquefaciens, Paenibacillus mucilaginosus, and Trichoderma harzianum, and the mass ratio of the three is 1:(1 - 2):(0.9 - 1.8).

[0017] Preferably, Bacillus amyloliquefaciens, Paenibacillus mucilaginosus, and Trichoderma harzianum are all strains carried by a reusable returnable technology experimental satellite.

[0018] The present invention preferably uses Bacillus amyloliquefaciens, Paenibacillus mucilaginosus, and Trichoderma harzianum carried by a reusable returnable technology experimental satellite as the microbial complex agent. By releasing specific active substances and participating in the chemical reactions of salts in the soil, it helps to reduce the soil salinity and is conducive to the growth of plants.

[0019] In some embodiments, the trace element composition is zinc sulfate and boric acid, and the mass ratio of the two is 1:(1 - 1.5).

[0020] In some embodiments, the vitamin B is vitamin B1.

[0021] In some embodiments, the preparation method of the modified medical stone includes the following steps:

[0022] 1) Add the medical stone and hydrogen peroxide solution into a reaction vessel, ultrasonically disperse evenly for 25 - 35 min, then react at 55 - 65 °C for 23 - 25 h. After the reaction, filter, wash, and dry to obtain the pretreated medical stone.

[0023] 2) Add the pretreated medical stone, polyglutamic acid, and sulfuric acid into dichloromethane, react at 70 - 80 °C for 10 - 12 h, filter, and collect the solid to obtain the modified medical stone.

[0024] In some embodiments, the mass ratio of the pretreated medical stone to polyglutamic acid is 1:(0.3 - 0.6).

[0025] The present invention first pre-treats medical stone to increase its reaction activity, and then modifies the medical stone with polyglutamic acid to obtain modified medical stone, which can effectively improve the water and fertilizer retention capacity of the soil. The possible reason is that the modified medical stone has a stronger adsorption force for microbial bacteria, prolongs the active time of microbial bacteria, and effectively improves the air permeability of the soil. In addition, by limiting the mass ratio of pre-treated medical stone to polyglutamic acid, the modifier can be evenly dispersed in the soil and is not easy to agglomerate, which is beneficial to the absorption of fertilizers by crop roots.

[0026] In the second aspect of the present invention, a preparation method of a saline-alkali soil modifier rich in salt-tolerant microorganisms is provided, including the following steps: stirring microbial complex bactericide, fulvic acid potassium, trace element composition, vitamin B, organic fertilizer, modified medical stone and copolymer at 40-50 °C for 2-3 h to obtain the product.

[0027] In the third aspect of the present invention, an application of a saline-alkali soil modifier rich in salt-tolerant microorganisms is provided, and the dosage is 15-25 kg / mu each time.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] (1) By modifying medical stone, preparing copolymer and compounding microbial complex bactericide with other components, the present invention prepares a soil modifier applicable to saline-alkali land and capable of promoting crop growth.

[0030] (2) The present invention first obtains an intermediate containing tertiary amine and sodium sulfonate from allyl chloride and sodium N-methyltaurate, then reacts with sodium lignosulfonate and then reacts with oxyresveratrol to obtain a copolymer. There are many hydrophilic groups such as sulfonic acid groups and tertiary amines on the copolymer, which enhances the water retention capacity of the soil and improves the air permeability of the soil at the same time, solves the problem that the sodium lignosulfonate chain segment is easy to break under light conditions, resulting in a decline in the use effect, and increases the fertilizer utilization rate.

[0031] (3) The present invention first pre-treats medical stone to increase its reaction activity, and then modifies the medical stone with polyglutamic acid. The modified medical stone has a stronger adsorption force for microbial bacteria, prolongs the active time of microbial bacteria, and can make the modifier evenly dispersed in the soil, solving the problems of easy agglomeration of medical stone and slow absorption of fertilizers by crop roots. Specific embodiments

[0032] The following will describe the present invention in combination with specific implementation schemes. It should be noted that the following examples are examples of the present invention, only for explaining the present invention, and not for limiting the present invention. Other combinations and various improvements within the concept of the present invention can be made without departing from the main idea or scope of the present invention.

[0033] In the following examples and comparative examples, the compounds and related reagents used can all be purchased from the market. The organic fertilizer is pig manure organic fertilizer, and γ-polyglutamic acid is purchased from Jiangsu Jiujia Biotechnology Co., Ltd., with an effective substance content of ≤25%. Before satellite launch, Bacillus amyloliquefaciens was preserved in the China General Microbiological Culture Collection Center, preservation number: CGMCC 1.15674, Paenibacillus mucilaginosus was preserved in the China Center for Industrial Culture Collection of Microorganisms, preservation number: CICC 21698, and Trichoderma harzianum was preserved in the China General Microbiological Culture Collection Center, preservation number: CGMCC 3.12990. The above strains were domesticated by being carried on a reusable recoverable technology experimental satellite, and the domestication time in space was 14 days.

[0034] In addition, it should be noted that the strains used in Examples 1-3 of the present invention are the strains before satellite launch, and the strains used in Examples 4-9 and Comparative Example 1 are the strains carried on a reusable recoverable technology experimental satellite.

[0035] Preparation Example 1

[0036] The preparation method of copolymer-1 includes the following steps:

[0037] (1) Add 5 g of allyl chloride and 10 g of sodium N-methyltaurinate to 100 ml of DMF, react at 80 °C for 6.5 h, and dry to obtain an intermediate.

[0038] (2) Add 4 g of the intermediate obtained in step (1), 10 g of sodium lignosulfonate, and 0.4 g of potassium persulfate to 20 ml, 50 ml, and 20 ml of deionized water respectively, stir at 45 °C for 35 min to obtain an intermediate aqueous solution, a sodium lignosulfonate aqueous solution, and a potassium persulfate aqueous solution respectively. Then, under a nitrogen atmosphere, heat to 50 °C, and add the potassium persulfate aqueous solution and the intermediate aqueous solution dropwise to the sodium lignosulfonate aqueous solution. Then heat to 80 °C and react for 2 h. Then add 20 ml of an ethanol solution containing 3 g of resveratrol oxide and continue to react for 1 h. Filter, wash, and dry to obtain copolymer-1.

[0039] Preparation Example 2

[0040] The preparation method of copolymer-2 is the same as that of Preparation Example 1, except that the addition amount of the intermediate in step (2) is 8 g.

[0041] Preparation Example 3

[0042] Preparation method of copolymer-3. The specific implementation is the same as that of Preparation Example 1, except that the addition amount of resveratrol oxide is 7 g.

[0043] Preparation Example 4

[0044] Preparation method of copolymer-4, comprising the following steps:

[0045] (1) Add 5 g of allyl chloride and 10 g of sodium N-methyltaurinate to 100 ml of DMF, react at 80 °C for 6.5 h, and dry to obtain an intermediate;

[0046] (2) Add 4 g of the intermediate obtained in step (1), 10 g of sodium lignosulfonate, and 0.4 g of potassium persulfate to 20 ml, 50 ml, and 20 ml of deionized water respectively, stir at 45 °C for 35 min to obtain an intermediate aqueous solution, a sodium lignosulfonate aqueous solution, and a potassium persulfate aqueous solution respectively. Then, under a nitrogen atmosphere, heat to 50 °C, and add the potassium persulfate aqueous solution and the intermediate aqueous solution dropwise to the sodium lignosulfonate aqueous solution. Then, heat to 80 °C and react for 2 h. Filter, wash, and dry to obtain copolymer-4.

[0047] Preparation Example 5

[0048] Preparation method of modified zeolite-1, comprising the following steps:

[0049] 1) Add 10 g of zeolite and 30 ml of 30 wt% hydrogen peroxide solution to a reaction vessel, disperse evenly by ultrasonic treatment for 30 min, and then react at 50 °C for 24 h. After the reaction, filter, wash, and dry to obtain pretreated zeolite;

[0050] 2) Add 5 g of pretreated zeolite, 2.5 g of γ-polyglutamic acid, and 5 ml of 90 wt% concentrated sulfuric acid to 100 ml of dichloromethane, react at 75 °C for 11 h, filter, and collect the solid to obtain modified zeolite-1.

[0051] Preparation Example 6

[0052] Preparation method of modified zeolite-2. The specific implementation is the same as that of Preparation Example 4, except that the addition amount of γ-polyglutamic acid is 4 g.

[0053] Example 1

[0054] A saline-alkali soil conditioner rich in salt-tolerant microorganisms, comprising the following raw materials in parts by weight: 0.2 part of microbial complex bactericide, 13 parts of potassium humate, 2.5 parts of trace element composition, 2 parts of vitamin B1, 25 parts of organic fertilizer, 20 parts of modified zeolite-1, and 3 parts of copolymer-1;

[0055] The microbial complex bactericide is a composition of Bacillus amyloliquefaciens at 100 billion CFU / g, Paenibacillus mucilaginosus at 20 billion CFU / g, and Trichoderma harzianum at 10 billion CFU / g, and the mass ratio of the three is 1:1.5:1.4; the trace element composition is zinc sulfate and boric acid, and the mass ratio of the two is 1:1.3.

[0056] In this example, the preparation method of the saline-alkali soil conditioner rich in salt-tolerant microorganisms comprises the following steps: The microbial complex bactericide, potassium humate, trace element composition, vitamin B1, organic fertilizer, modified zeolite-1, and copolymer-1 are stirred at 45 °C for 2.5 h to obtain the product.

[0057] Example 2

[0058] A saline-alkali soil conditioner rich in salt-tolerant microorganisms, calculated by weight, comprises the following raw materials: 0.1 part of microbial complex bactericide, 10 parts of potassium humate, 2 parts of trace element composition, 1 part of vitamin B1, 20 parts of organic fertilizer, 10 parts of modified zeolite-1, and 2 parts of copolymer-1;

[0059] The microbial complex bactericide is a composition of Bacillus amyloliquefaciens at 100 billion CFU / g, Paenibacillus mucilaginosus at 20 billion CFU / g, and Trichoderma harzianum at 10 billion CFU / g, and the mass ratio of the three is 1:1:0.9; the trace element composition is zinc sulfate and boric acid, and the mass ratio of the two is 1:1.

[0060] In this example, the preparation method of the saline-alkali soil conditioner rich in salt-tolerant microorganisms comprises the following steps: The microbial complex bactericide, potassium humate, trace element composition, vitamin B1, organic fertilizer, modified zeolite-1, and copolymer-1 are stirred at 40 °C for 3 h to obtain the product.

[0061] Example 3

[0062] A saline-alkali soil conditioner rich in salt-tolerant microorganisms, calculated by weight, comprises the following raw materials: 0.3 part of microbial complex bactericide, 15 parts of potassium humate, 3 parts of trace element composition, 3 parts of vitamin B1, 30 parts of organic fertilizer, 30 parts of modified zeolite-1, and 4 parts of copolymer-1;

[0063] The microbial complex bactericide is a composition of Bacillus amyloliquefaciens at 100 billion CFU / g, Paenibacillus mucilaginosus at 20 billion CFU / g, and Trichoderma harzianum at 10 billion CFU / g, and the mass ratio of the three is 1:2:1.8; the trace element composition is zinc sulfate and boric acid, and the mass ratio of the two is 1:1.5.

[0064] The preparation method of the saline-alkali soil conditioner rich in salt-tolerant microorganisms in this embodiment comprises the following steps: Mix the microbial complex bactericide, potassium humate, trace element composition, vitamin B1, organic fertilizer, modified picrolite-1 and copolymer-1 at 50°C for 2 hours to obtain the product.

[0065] Example 4

[0066] A saline-alkali soil conditioner rich in salt-tolerant microorganisms, by weight, comprises the following raw materials: 0.2 part of microbial complex bactericide, 13 parts of potassium humate, 2.5 parts of trace element composition, 2 parts of vitamin B1, 25 parts of organic fertilizer, 20 parts of modified picrolite-1, and 3 parts of copolymer-1;

[0067] The microbial complex bactericide is a composition of Bacillus amyloliquefaciens at 100 billion CFU / g, Paenibacillus mucilaginosus at 20 billion CFU / g, and Trichoderma harzianum at 10 billion CFU / g, and is the strain carried by the reusable return-type technology experimental satellite. The mass ratio of the three is 1:1.5:1.4; the trace element composition is zinc sulfate and boric acid, and the mass ratio of the two is 1:1.3.

[0068] The preparation method of the saline-alkali soil conditioner rich in salt-tolerant microorganisms in this embodiment comprises the following steps: Mix the microbial complex bactericide, potassium humate, trace element composition, vitamin B1, organic fertilizer, modified picrolite-1 and copolymer-1 at 45°C for 2.5 hours to obtain the product.

[0069] Example 5

[0070] A saline-alkali soil conditioner rich in salt-tolerant microorganisms and its preparation method. The specific implementation method is the same as that of Example 4, except that copolymer-1 is replaced with copolymer-2 in equal amount.

[0071] Example 6

[0072] A saline-alkali soil conditioner rich in salt-tolerant microorganisms and its preparation method. The specific implementation method is the same as that of Example 4, except that copolymer-1 is replaced with copolymer-3 in equal amount.

[0073] Example 7

[0074] A saline-alkali soil conditioner rich in salt-tolerant microorganisms and its preparation method. The specific implementation method is the same as that of Example 4, except that copolymer-1 is replaced with copolymer-4 in equal amount.

[0075] Example 8

[0076] A saline-alkali soil conditioner rich in salt-tolerant microorganisms and its preparation method. The specific implementation method is the same as that of Example 4, except that modified picrolite-1 is replaced with modified picrolite-2 in equal amount.

[0077] Comparative Example 1

[0078] A saline-alkali soil conditioner rich in salt-tolerant microorganisms and its preparation method. The specific implementation manner is the same as that of Example 1, except that the modified zeolite-1 is replaced with zeolite in equal amount.

[0079] Performance Test

[0080] The following tests were carried out on the saline-alkali soil conditioners rich in salt-tolerant microorganisms obtained in the above examples and comparative examples:

[0081] Using the field test method, experimental fields in the saline-alkali areas of Shaanxi were selected. The experimental fields were irrigated fields. The tested corn variety was Jidan 33. The soil conditioners prepared in each example and comparative example were used as the base fertilizer for corn planting. 10 days before sowing, it was deeply applied at 13 cm, 23 kg was used per mu of land, and 2 mu of land was treated. 3 points were randomly arranged, and each point was 30 m 2 , and then topdressing was carried out once each at the large and small trumpet mouth stages and the tasseling stage, 20 kg was used per mu of land. After the corn matured, all the corn ears were broken off and weighed on-site. The total weight was recorded as the yield of the experimental group. At the same time, 10 ears of corn were randomly taken back from each point to measure the ear length and ear weight, and the average value was taken. After natural air drying, the seeds were counted, and the corn yield with a moisture content of 14% was calculated. The 100-grain weight was measured and the average value was taken. In the same way, the conventional corn fertilization amount was used as the blank group, and the yield, ear length, ear weight and 100-grain weight were measured in the same way respectively. The conventional fertilization amount was CO(NH2)2 150 kg·hm 2 , P2O5 75 kg·hm 2 , K2O 45 kg·hm 2 , and the yield increase rate was calculated. Yield increase rate = (yield of experimental group - yield of blank group) / yield of blank group × 100%.

[0082] The test results are shown in Table 1:

[0083] Table 1

[0084]

[0085]

[0086] From the comparison of the experimental data in Examples 1-3 of Table 1, it can be seen that this soil conditioner can improve saline-alkali land, enabling corn to maintain a relatively high ear length and ear weight, and increasing the yield. From the comparison between Example 4 and Example 1, it can be seen that using the strain carried by the reusable return-type technology test satellite further improves the ear length, ear weight and yield of corn, and further enhances the improvement effect on the land. From the comparison between Examples 5 and 6 and Example 4, it can be seen that changing the ratio of the intermediate, sodium lignosulfonate and resveratrol oxide may lead to changes in the adsorption capacity of the copolymer with the soil, changes in the air permeability and water retention of the soil, and a deterioration in the improvement effect of the conditioner, resulting in a decrease in the yield of corn. From the comparison between Example 7 and Example 4, it can be seen that the absence of resveratrol oxide may cause sodium lignosulfonate to decompose easily, resulting in a decline in the use effect, and thus leading to a decline in all indicators of corn and a deterioration in the improvement effect of the conditioner. From the comparison between Example 8 and Example 4, it can be seen that changing the ratio of pretreated zeolite and polyglutamic acid may lead to too strong activity of microorganisms in the soil, the soil being too loose, affecting the water-holding capacity of the soil, and resulting in a decrease in the yield increase rate. From the comparison between Comparative Example 1 and Example 4, it can be seen that directly using zeolite has poor dispersibility, the soil is prone to hardening, and the yield is low.

[0087] The above embodiments are only for illustrating the technical concept and features of the present invention, and the purpose is to enable those who are familiar with this technology to understand the content of the present invention and implement it. It should not be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit and essence of the present invention should be covered within the protection scope of the present invention.

Claims

1. A saline-alkali soil conditioner rich in salt-tolerant microorganisms, characterized in that: The invention comprises the following raw materials in parts by weight: 0.1-0.3 parts of microbial composite agent, 10-15 parts of potassium humate, 2-3 parts of trace element composition, 1-3 parts of vitamin B1, 20-30 parts of organic fertilizer, 10-30 parts of modified medical stone and 2-4 parts of copolymer.

2. The saline-alkali soil conditioner rich in salt-tolerant microorganisms according to claim 1, characterized in that: The preparation method of the copolymer comprises the following steps: (1) adding allyl chloride and sodium N-methyltaurate to DMF, reacting at 75-85° C. for 6-7 hours, and drying to obtain an intermediate; (2) The intermediate, lignin sulfonate and initiator obtained in step (1) are added to deionized water respectively, and stirred at 40-50° C. for 30-40 min to obtain an intermediate aqueous solution, a lignin sulfonate aqueous solution and an initiator aqueous solution respectively. Then, under a nitrogen atmosphere, the temperature is raised to 45-55° C., the initiator aqueous solution and the intermediate aqueous solution are added dropwise to the lignin sulfonate aqueous solution, and then the temperature is raised to 75-85° C. and the reaction is carried out for 1.5-2.5 h. Then, an ethanol solution of oxidized resveratrol is added, the reaction is continued for 0.5-1.5 h, and the copolymer is filtered, washed and dried.

3. The saline-alkali soil conditioner rich in salt-tolerant microorganisms according to claim 2, characterized in that: The mass ratio of the intermediate, lignin sulfonate and oxidized resveratrol in step (2) is (0.2-0.6):1:(0.2-0.5).

4. The saline-alkali soil conditioner rich in salt-tolerant microorganisms according to claim 1, characterized in that: The microbial composite bacterial agent is a composition of Bacillus amyloliquefaciens, Paenibacillus peptoneus and Trichoderma harzianum, and the mass ratio of the three is 1:(1-2):(0.9-1.8).

5. The saline-alkali soil conditioner rich in salt-tolerant microorganisms according to claim 1, characterized in that: The trace element composition is zinc sulfate and boric acid, and the mass ratio of the two is 1:(1-1.5).

6. The saline-alkali soil conditioner rich in salt-tolerant microorganisms according to claim 1, characterized in that: The vitamin B is vitamin B1.

7. The saline-alkali soil conditioner rich in salt-tolerant microorganisms according to claim 1, characterized in that: The preparation method of the modified medical stone comprises the following steps: 1) adding medical stone and hydrogen peroxide solution into a reaction container, dispersing uniformly by ultrasonication for 25-35 minutes, and then reacting at 55-65° C. for 23-25 ​​hours. After the reaction is completed, filtering, washing and drying are performed to obtain pretreated medical stone; 2) adding the pretreated medical stone, polyglutamic acid and sulfuric acid into dichloromethane, reacting at 70-80° C. for 10-12 hours, filtering, collecting the solid, and obtaining the modified medical stone.

8. The saline-alkali soil conditioner rich in salt-tolerant microorganisms according to claim 7, characterized in that: The mass ratio of the pretreated medical stone to polyglutamic acid is 1:(0.3-0.6).

9. A method for preparing the saline-alkali soil conditioner rich in salt-tolerant microorganisms according to any one of claims 1 to 8, characterized in that: The following steps are involved: The microbial composite agent, potassium humate, trace element composition, vitamin B, organic fertilizer, modified medical stone and copolymer are stirred at 40-50° C. for 2-3 hours to obtain the product.

10. Use of the saline-alkali soil conditioner rich in salt-tolerant microorganisms according to any one of claims 1 to 8 or the saline-alkali soil conditioner obtained by the preparation method according to claim 9, characterized in that: The dosage is 15-25 kg / mu each time.

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