Acidic soil conditioner and its preparation method and application

Abstract

The present invention relates to an acidic soil conditioner and a preparation method and application thereof. The acidic soil conditioner includes a carbon-based acid conditioner, a mineral source conditioner and a microbial preparation. The preparation method of the acidic soil conditioner includes: calcining and grinding oyster shells to obtain oyster shell powder; mixing oyster shell powder, modified biochar and quicklime to obtain a carbon-based acid conditioner; crushing and sieving at least one of attapulgite, montmorillonite and dolomite to obtain a mineral source conditioner; mixing Bacillus subtilis, Bacillus licheniformis and Trichoderma harzianum in proportion to obtain a microbial preparation; the preparation of the acidic soil conditioner: uniformly mixing the prepared carbon-based acid conditioner, mineral source conditioner and microbial preparation, and then coating to obtain a coated acidic soil conditioner. The present invention also provides an application of an acidic soil conditioner for conditioning, improving and repairing degraded acidic soil. The present invention solves the problems of soil acidification and nutrient deficiency at the same time.

Description

Technical Field

[0001] The invention relates to the technical field of soil improvement, and in particular to an acidic soil conditioner and a preparation method and application thereof. Background Art

[0002] With the increasing global industrialization and agricultural activities, the problem of soil acidity and alkalinity has gradually become prominent, especially acidic soil has had a serious impact on crop growth and soil ecology. In China, the southern region is the main distribution area of ​​acidic soil, accounting for about 22.7% of the country's total land area. The hot and rainy climate in the south has led to severe leaching of soil and its parent material, resulting in a large amount of leaching of base ions in the soil, leading to widespread soil acidification.

[0003] Soil acidification not only accelerates the loss of soil nutrients, reduces soil cation exchange capacity (CEC) and base saturation (BS), thereby reducing soil nutrient content and nutrient supply capacity, and thus causing soil fertility degradation, but also increases the active aluminum content in the soil, causing aluminum poisoning to plants. At the same time, the increased activity of aluminum, manganese and heavy metal elements further leads to nutrient deficiency and element poisoning, seriously affecting the normal growth of plants, degrading farmland ecosystems, reducing the stability and biodiversity of farmland ecosystems, and ultimately leading to a decline in crop yield and quality.

[0004] In response to the problem of soil acidification, the traditional improvement method is mainly to apply alkaline substances such as lime to neutralize soil acidity and increase soil pH. Although this method is effective to a certain extent, the application of lime will cause problems such as soil compaction, nutrient deficiency and soil re-acidification, and it cannot completely solve the problem of lack of effective nutrients in the soil. In the process of soil acidification improvement, it is equally important to increase the content of effective nutrients in the soil. Soil acidification is often accompanied by phosphorus fixation, nitrogen loss, and the loss of basic ions such as calcium and magnesium. Therefore, it is particularly important to develop an acidic soil conditioner that can effectively neutralize soil acidity and provide a variety of nutrients.

[0005] However, although the existing acidic soil conditioners have a certain effect on regulating soil pH, they are still insufficient in improving crop growth ability, effectively neutralizing soil acidity, and having little effect on the activity of microorganisms in the soil. In addition, these conditioners also have problems such as slow soil acidity correction speed, poor nitrogen, phosphorus and potassium fixation effects, low yield increase and poor overall performance. Summary of the invention

[0006] In view of this, the object of the present invention is to provide an acidic soil conditioner and a preparation method and application thereof, so as to solve the problems of soil acidification and nutrient deficiency at the same time.

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

[0008] An acidic soil conditioner comprises, by weight, 30 to 70 parts of a carbon-based acid conditioner, 20 to 40 parts of a mineral source conditioner and 10 to 20 parts of a microbial preparation.

[0009] Among them, acidic soil conditioners are used for acidic soil conditioning, which can improve the acidity of acidic soil and increase the productivity of acidic soil. When applied, they are spread mechanically or manually, applied in furrows and holes.

[0010] The quicklime in the acidifier can make preliminary improvements to the acidic soil to quickly achieve the purpose of increasing the pH. By mixing oyster shell powder and quicklime, part of the quicklime can be mixed into the gaps of the oyster shell powder. Through the enrichment effect of oyster shell powder, the quicklime can slow down the release of heat when releasing heat, while increasing the effect of quicklime on raising soil temperature and killing pathogens in the soil, while reducing its impact on soil moisture. Long-term use of quicklime will cause rapid decomposition and loss of organic matter in the soil, reduction of humus, fixation of trace elements by the soil, and loss of nutrients, and cause soil compaction and other problems. Therefore, it is difficult to achieve the effect of soil improvement only through acidifiers. On the basis of acidifiers, adding mineral source conditioners can further improve the soil, including further improving pH and improving the soil's nutrient supply and water and fertilizer retention capabilities.

[0011] Microbial agents can improve the soil itself or the soil barrenness, malnutrition and other problems caused by the addition of quicklime. They can supplement beneficial bacteria and overcome the defect of killing some beneficial bacteria when quicklime acts. On this basis, Trichoderma harzianum can quickly colonize in the rhizosphere and phyllosphere of plants, occupy the microbial ecological niche on the surface of the plant body, and prevent pathogenic fungi from multiplying in the plant root system and leaf surface, thereby protecting the plant roots and leaves from infection by pathogens, so as to prevent diseases and promote crop growth.

[0012] In general, oyster shell powder is rich in Ca elements required for plant growth and development, and dolomite is rich in Mg elements required for plant growth and development, so the exchangeable base ions of the soil are significantly improved. Similarly, due to the application of conditioners, the soil acidity is reduced, thereby reducing the risk of soil base ions being reduced due to leaching and other means, and can make up for the loss of nutrients in the soil itself, thereby improving the nutrient supply capacity of acidic soils and effectively improving the quality and yield of crops. At the same time, oyster shell powder can improve soil structure and effectively improve soil compaction problems caused by the addition of quicklime because of its porous, strong adsorption, and ion exchange properties. The conditioner mixed with quicklime, dolomite, and oyster shells will significantly increase the pH in the soil and reduce the exchangeable acid content. This is mainly because the CaO component it contains reacts chemically with H2O in the soil and ionizes OH -ions, thereby increasing soil pH, and OH - It can also exchange Al in the soil 3+ The reaction generates insoluble aluminum hydroxide, thereby reducing the exchangeable Al in the soil. 3+ content.

[0013] Preferably, the carbon-based acid regulator comprises, by weight: 10 to 20 parts of modified biochar, 40 to 50 parts of quicklime and 30 to 40 parts of oyster shell powder.

[0014] By adding modified biochar to the carbon-based acidifier, the buffering performance of the conditioner is effectively enhanced, the specific surface area is increased, and the long-term effectiveness of the soil acidification conditioner is improved.

[0015] Preferably, the modified biochar is obtained by modifying rice husk biochar with calcium phosphate, potassium phosphate and magnesium chloride.

[0016] Preferably, the mineral source conditioning agent is selected from quicklime and / or dolomite.

[0017] Preferably, the mineral source conditioning agent is selected from natural dolomite powder.

[0018] Preferably, the microbial preparation is selected from at least one of Bacillus subtilis, Bacillus licheniformis and Trichoderma harzianum.

[0019] Preferably, the microbial preparation is selected from Trichoderma harzianum.

[0020] Preferably, the acidic soil conditioner is a coated acidic soil conditioner, and the coating amount is 1%;

[0021] The coating material of the coated acidic soil conditioner is selected from at least one of humic acid, alginic acid and chitosan.

[0022] By coating the acidic soil conditioner to form a uniform film on the surface of the acidic soil conditioner, the release time of the acidic soil conditioner is effectively controlled.

[0023] The present invention also provides a method for preparing the acidic soil conditioner according to the present invention, comprising the following steps:

[0024] Preparation of carbon-based acid regulator: calcining and grinding oyster shells to obtain oyster shell powder; mixing oyster shell powder, modified biochar and quicklime in proportion to obtain an acid regulator;

[0025] Preparation of the mineral source conditioning agent: crushing and sieving at least one of attapulgite, montmorillonite and / or dolomite to obtain the mineral source conditioning agent;

[0026] Preparation of the microbial preparation: Bacillus subtilis, Bacillus licheniformis and Trichoderma harzianum are mixed according to a proportion to obtain the microbial preparation;

[0027] Preparation of acidic soil conditioner: the prepared carbon-based acid conditioner, mineral source conditioner and coated microbial preparation are mixed and granulated, and then coated to obtain coated acidic soil conditioner.

[0028] Preferably, the calcination temperature of the oyster shell is 500° C. to 700° C., and the calcination time is 2 h to 3 h.

[0029] Preferably, the preparation method of the modified biochar is: take husk biochar, add calcium phosphate, potassium phosphate and magnesium chloride to prepare a suspension, stir and shake the suspension for 24 hours, filter, and dry at a temperature of 100°C; then carbonize for 60 minutes in a nitrogen environment and a temperature of 600°C to obtain modified biochar.

[0030] Preferably, the dolomite is selected from natural dolomite with CaO>30%, MgO>15%, and SiO2>10%, and the particle size of the natural dolomite after crushing and sieving is less than 0.15 mm. CaO>30% means that the mass percentage of calcium oxide is greater than 30%, MgO>15% means that the mass percentage of magnesium oxide is greater than 15%, and SiO2>10% means that the mass percentage of silicon dioxide is greater than 10%.

[0031] Preferably, the microbial preparation is prepared by mixing Bacillus subtilis, Bacillus licheniformis and Trichoderma harzianum in a mass ratio of 1:1:1 to obtain the microbial preparation.

[0032] Among them, natural dolomite is crushed by mechanical crushing.

[0033] Preferably, the preparation of the acidic soil conditioner specifically comprises: mixing 420g-450g of polyethylene glycol-400, 80g-100g of glycerol and 12g-15g of concentrated sulfuric acid and heating to 170°C, and then adding 100g-130g of a mixture of humic acid, alginic acid and chitosan; continuing the liquefaction reaction for 90 minutes and then cooling to room temperature to obtain a liquefied liquid; the mass ratio of humic acid, alginic acid and chitosan in the mixture is 2:1:1;

[0034] 1 kg of a mixed granulated conditioner of a carbon-based acid conditioner, a mineral source conditioner and a coated microbial preparation is heated to 75°C for 10 to 20 minutes, and then the liquefied liquid and isocyanate are evenly mixed in a mass ratio of 1:1, and then slowly dripped onto the surface of the conditioner to form a coating layer on the surface of the conditioner. The curing reaction is performed for 15 minutes to obtain a coated acidic soil conditioner.

[0035] The curing reaction is the natural cementation and solidification of the coating liquid on the surface of the acidic soil conditioner.

[0036] Among them, polyethylene glycol-400 is a commonly used liquefier, which is used to improve the modeling and controlled release properties of the coating material. Glycerol is a polyhydroxy compound that participates in the synthesis of polyurethane and enhances the crosslinking density and water resistance of the coating material. Isocyanate is one of the key raw materials for polyurethane synthesis, which reacts with polyols such as polyethylene glycol-400 to produce polyurethane film materials.

[0037] The present invention also provides a use of the acidic soil conditioner according to the present invention, wherein the acidic soil conditioner is used for conditioning, improving and repairing degraded acidic soil.

[0038] Beneficial effects of the present invention:

[0039] The acidic soil conditioner of the present invention can rapidly increase soil pH value, improve soil acidity, reduce soil exchangeable acid content, and weaken the toxic effect of soil active aluminum on plants by using a carbon-based acid conditioner, a mineral source conditioner, and a microbial preparation in combination. The addition of the microbial preparation can also improve the vitality of crop root systems, improve the stress resistance and disease and pest resistance of crops, promote the activity of soil microorganisms, promote the release of soil fast-acting nutrients, improve soil nutrients, significantly improve the stability, air permeability, and water permeability of soil structure, increase the activity of soil microorganisms, promote the release of fast-acting nutrients, improve the antibacterial and antibacterial properties of crops, and has strong nitrogen, phosphorus, and potassium fixation functions, effectively enhances plant photosynthesis, promotes soil microbial reproduction, and can greatly increase crop yields, thereby solving the problems of soil acidification and nutrient deficiency at the same time. The acidic soil conditioner has the advantages of low cost, good acidification and fertilization effect, long duration, increased crop yield, and environmental protection, and has the advantages of being low cost, good acidification and fertilization effect, long duration, increased crop yield, and environmental protection, and has the value of popularization and application in the field of soil improvement technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 A flow chart of a method for preparing an acidic soil conditioner; DETAILED DESCRIPTION

[0041] The following will describe the embodiments of the present invention with reference to the preferred embodiments, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for illustrating the present invention, not for limiting the scope of protection of the present invention.

[0042] The present invention intends to disclose an acidic soil conditioner and a preparation method and application thereof, so as to solve the problems of soil acidification and nutrient deficiency at the same time.

[0043] The acidic soil conditioner comprises, by weight, 30 to 70 parts of a carbon-based acid conditioner, 20 to 40 parts of a mineral source conditioner and 10 to 20 parts of a microbial preparation.

[0044] Among them, acidic soil conditioners are used for acidic soil conditioning, which can improve the acidity of acidic soil and increase the productivity of acidic soil. When applied, they are spread mechanically or manually, applied in furrows and holes.

[0045] In some embodiments, the carbon-based acid regulator includes, by weight: 10 to 20 parts of modified biochar, 40 to 50 parts of quicklime, and 30 to 40 parts of oyster shell powder.

[0046] In some embodiments, the modified biochar is obtained by modifying rice husk biochar with calcium phosphate, potassium phosphate, and magnesium chloride.

[0047] In some embodiments, the mineral source conditioning agent is selected from at least one of attapulgite, montmorillonite, and dolomite.

[0048] Exemplarily, the mineral source conditioning agent is selected from dolomite powder.

[0049] In some embodiments, the microbial agent is selected from at least one of Bacillus subtilis, Bacillus licheniformis, and Trichoderma harzianum.

[0050] Exemplarily, the microbial agent is selected from Trichoderma harzianum.

[0051] In some embodiments, the acidic soil conditioner is a coated acidic soil conditioner, and the coating amount is 1%;

[0052] The coating material of the coated acidic soil conditioner is selected from at least one of humic acid, alginic acid and chitosan.

[0053] In some embodiments, a method for preparing the acidic soil conditioner in any of the above embodiments is also provided, comprising the following steps:

[0054] Preparation of carbon-based acid regulator: calcining and grinding oyster shells to obtain oyster shell powder; mixing oyster shell powder, modified biochar and quicklime in proportion to obtain an acid regulator;

[0055] Preparation of the mineral source conditioning agent: at least one of attapulgite, montmorillonite and dolomite is crushed and sieved to obtain the mineral source conditioning agent;

[0056] Preparation of the microbial preparation: Bacillus subtilis, Bacillus licheniformis and Trichoderma harzianum are mixed according to a proportion to obtain the microbial preparation;

[0057] Preparation of acidic soil conditioner: the prepared carbon-based acid conditioner, mineral source conditioner and coated microbial preparation are mixed and granulated, and then coated to obtain coated acidic soil conditioner.

[0058] In some embodiments, the oyster shell is calcined at a temperature of 500° C. to 700° C., and the calcination time is 2 h to 3 h.

[0059] In some embodiments, the preparation method of modified biochar is: take husk biochar, add calcium phosphate, potassium phosphate and magnesium chloride to prepare a suspension, stir and shake the suspension for 24 hours, filter, and dry at a temperature of 100°C; then carbonize for 60 minutes in a nitrogen environment and a temperature of 600°C to obtain modified biochar.

[0060] In some embodiments, the dolomite is selected from natural dolomite with CaO>30%, MgO>15%, and SiO2>10%, and the particle size of the natural dolomite after crushing and sieving is less than 0.15 mm.

[0061] Among them, natural dolomite is crushed by mechanical crushing.

[0062] Exemplarily, the preparation of the microbial preparation includes: mixing Bacillus subtilis, Bacillus licheniformis and Trichoderma harzianum in a mass ratio of 1:1:1 to obtain the microbial preparation.

[0063] In some embodiments, the preparation of the acidic soil conditioner specifically includes: mixing 420g to 450g of polyethylene glycol-400, 80g to 100g of glycerol and 12g to 15g of concentrated sulfuric acid and heating to 170°C, then adding 100g to 130g of a mixture of humic acid, alginic acid and chitosan (in the mixture, the mass ratio of humic acid, alginic acid and chitosan is 2:1:1); continuing the liquefaction reaction for 90 minutes and then cooling to room temperature to obtain a liquefied liquid;

[0064] 1 kg of a granulated conditioner made by mixing a carbon-based acid conditioner, a mineral source conditioner and a microbial preparation is heated to 75°C for 10 to 20 minutes, and then the liquefied liquid and isocyanate are evenly mixed in a mass ratio of 1:1, and then slowly dripped onto the surface of the conditioner to form a coating layer on the surface of the conditioner. The curing reaction is performed for 15 minutes to obtain a coated acidic soil conditioner.

[0065] Exemplarily, the preparation of the liquefied liquid includes: mixing 420g of polyethylene glycol-400, 80g of glycerol and 15g of concentrated sulfuric acid and heating them to 170°C, and then adding 100g of humic acid, alginate and chitosan (in the mixture, the mass ratio of humic acid, alginate and chitosan is 2:1:1); continuing the liquefaction reaction for 90 minutes and then cooling to room temperature to obtain a liquefied liquid.

[0066] In some embodiments, there is also provided a use of the acidic soil conditioner in any of the above embodiments for conditioning, improving and repairing degraded acidic soil.

[0067] In order to make the technical problems, technical solutions and beneficial effects solved by the present application clearer, the preparation method of the acidic soil conditioner of the present invention will be further described in detail below in conjunction with specific embodiments and drawings. Obviously, the specific embodiments described are only part of the embodiments of the present application, rather than all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present application and its applications. Based on the specific embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work belong to the scope of protection of the present application.

[0068] If no specific techniques or conditions are specified in the specific embodiments, the techniques or conditions described in the literature in the field or the product instructions are used. If no manufacturer is specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0069] Example 1

[0070] like Figure 1 As shown, a method for preparing an acidic soil conditioner comprises the following steps:

[0071] S1. Preparation of modified biochar: 100 g of rice husk biochar was added with 10 g of calcium phosphate, 5 g of potassium phosphate and 5 g of magnesium chloride to prepare a suspension, the suspension was stirred and shaken for 24 h, filtered, and dried at a temperature of 100 ° C; then carbonized at a temperature of 600 ° C for 60 min in a nitrogen environment to obtain modified biochar;

[0072] S2. Preparation of a carbon-based acid regulator: calcining oyster shells at 600° C. for 3 h, and then mechanically grinding them to obtain oyster shell powder; mixing 300 g of oyster shell powder, 100 g of modified biochar and 200 g of quicklime to obtain a carbon-based acid regulator;

[0073] S3. Preparation of mineral source conditioning agent: natural dolomite with CaO>30%, MgO>15%, and SiO2>10% is mechanically crushed and sieved to obtain natural dolomite powder with a particle size of less than 0.15 mm, that is, the mineral source conditioning agent;

[0074] S4, preparation of a microbial preparation: mixing Bacillus subtilis, Bacillus licheniformis and Trichoderma harzianum in a mass ratio of 1:1:1 to obtain a microbial preparation;

[0075] S5. Preparation of an acidic soil conditioner: 420 g of polyethylene glycol-400, 80 g of glycerol and 15 g of concentrated sulfuric acid were mixed and heated to 170° C., and then 100 g of a mixture of humic acid, alginic acid and chitosan was added; the liquefaction reaction was continued for 90 minutes and then cooled to room temperature to obtain a liquefied liquid; the mass ratio of humic acid, alginic acid and chitosan in the mixture was 2:1:1;

[0076] 1 kg of the mixed granulated conditioner prepared by 600 g of the carbon-based acid conditioner prepared in S2, 300 g of the mineral source conditioner prepared in S3 and 100 g of the microbial preparation prepared in S4 was heated to 75°C for 10 minutes, and then 5 g of the liquefied liquid and 5 g of isocyanate were mixed evenly and slowly dripped onto the surface of the conditioner to form a coating layer on the surface of the conditioner. The curing reaction was carried out for 15 minutes to obtain a coated acidic soil conditioner.

[0077] Example 2

[0078] like Figure 1 As shown, a method for preparing an acidic soil conditioner comprises the following steps:

[0079] S1. Preparation of modified biochar: 100 g of rice husk biochar was added with 10 g of calcium phosphate, 5 g of potassium phosphate and 5 g of magnesium chloride to prepare a suspension, the suspension was stirred and shaken for 24 h, filtered, and dried at a temperature of 100 ° C; then carbonized at a temperature of 600 ° C for 60 min in a nitrogen environment to obtain modified biochar;

[0080] S2. Preparation of a carbon-based acid regulator: calcining oyster shells at 600° C. for 3 h, and then mechanically grinding them to obtain oyster shell powder; mixing 300 g of oyster shell powder, 100 g of modified biochar and 200 g of quicklime to obtain a carbon-based acid regulator;

[0081] S3. Preparation of mineral source conditioning agent: natural dolomite with CaO>30%, MgO>15%, and SiO2>10% is mechanically crushed and sieved to obtain natural dolomite powder with a particle size of less than 0.15 mm, that is, the mineral source conditioning agent;

[0082] S4, preparation of a microbial preparation: mixing Bacillus subtilis, Bacillus licheniformis and Trichoderma harzianum in a mass ratio of 1:1:1 to obtain a microbial preparation;

[0083] S5. Preparation of an acidic soil conditioner: 420 g of polyethylene glycol-400, 80 g of glycerol and 15 g of concentrated sulfuric acid were mixed and heated to 170° C., and then 100 g of a mixture of humic acid, alginic acid and chitosan was added; the liquefaction reaction was continued for 90 minutes and then cooled to room temperature to obtain a liquefied liquid; the mass ratio of humic acid, alginic acid and chitosan in the mixture was 2:1:1;

[0084] 1 kg of the mixed granulated conditioner of 500 g of the carbon-based acid conditioner prepared in S2, 400 g of the mineral source conditioner prepared in S3 and 100 g of the coated microbial preparation prepared in S4 was heated to 75°C for 10 minutes, and then 5 g of the liquefied liquid and 5 g of isocyanate were evenly mixed and slowly dripped onto the surface of the conditioner to form a coating layer on the surface of the conditioner. The curing reaction was carried out for 15 minutes to obtain the coated acidic soil conditioner.

[0085] Example 3

[0086] like Figure 1 As shown, a method for preparing an acidic soil conditioner comprises the following steps:

[0087] S1. Preparation of modified biochar: 100 g of rice husk biochar was added with 10 g of calcium phosphate, 5 g of potassium phosphate and 5 g of magnesium chloride to prepare a suspension, the suspension was stirred and shaken for 24 h, filtered, and dried at a temperature of 100 ° C; then carbonized at a temperature of 600 ° C for 60 min in a nitrogen environment to obtain modified biochar;

[0088] S2. Preparation of a carbon-based acid regulator: calcining oyster shells at 600° C. for 3 h, and then mechanically grinding them to obtain oyster shell powder; mixing 300 g of oyster shell powder, 100 g of modified biochar and 200 g of quicklime to obtain a carbon-based acid regulator;

[0089] S3. Preparation of mineral source conditioning agent: natural dolomite with CaO>30%, MgO>15%, and SiO2>10% is mechanically crushed and sieved to obtain natural dolomite powder with a particle size of less than 0.15 mm, that is, the mineral source conditioning agent;

[0090] S4, preparation of a microbial preparation: mixing Bacillus subtilis, Bacillus licheniformis and Trichoderma harzianum in a mass ratio of 1:1:1 to obtain a microbial preparation;

[0091] S5. Preparation of an acidic soil conditioner: 420 g of polyethylene glycol-400, 80 g of glycerol and 15 g of concentrated sulfuric acid were mixed and heated to 170° C., and then 100 g of a mixture of humic acid, alginic acid and chitosan was added; the liquefaction reaction was continued for 90 minutes and then cooled to room temperature to obtain a liquefied liquid; the mass ratio of humic acid, alginic acid and chitosan in the mixture was 2:1:1;

[0092] A mixed granulation of 500g of the carbon-based acid conditioner prepared in S2, 300g of the mineral source conditioner prepared in S3 and 200g of the coated microbial preparation prepared in S4 to prepare 1kg of the conditioner is heated to 75°C for preheating for 10 minutes, and then 5g of the liquefied liquid and 5g of the isocyanate are evenly mixed and slowly dripped onto the surface of the conditioner to form a coating layer on the surface of the conditioner. The curing reaction is carried out for 15 minutes to obtain a coated acidic soil conditioner.

[0093] Test Example 1

[0094] The test soil was collected from Shuangxiqiao Town, Xianning District, Xianning City, Hubei Province (29°56′40″N, 114.3°30′46″E). There was no previous crop, the soil type was brown-red soil, and the altitude was 45.6m. This area is located in the southeastern part of Hubei Province, in the transition zone between the Mufu Mountain System and the Jianghan Plain. The terrain is high in the southeast and low in the northwest. It has a subtropical monsoon humid climate, with an average annual temperature of 16.8℃ and an average annual rainfall of 1577.4mm. The 0-20cm tillage layer of soil was collected using the "5-point sampling method", and the soil was brought back to the laboratory after impurities were removed. After the soil was air-dried, roots, gravel and other impurities were removed, and then sieved through a 2mm sieve for potted experiments. The basic properties of the soil are: pH value is 4.5, the total exchangeable acid content is 4.21cmol·kg -1 , the soil cation exchange capacity is 9.01 cmol kg -1 , total nitrogen content is 1.32g·kg -1 , the total phosphorus content is 1.32g·kg -1 , total potassium content is 1.32g·kg -1 .

[0095] Before the formal pot test, the air-dried soil was pre-cultured and activated to activate soil microorganisms and eliminate the dry-wet effect. Control Example 1 was treated without adding any conditioner, and Control Example 2 was treated by adding quicklime. According to the above-mentioned Example 1, Example 2 and Example 3, Control Example 1 and Control Example 2 were mixed evenly with the air-dried soil and potted, and the soil moisture content was adjusted to 20%. Deionized water was added once every 1 day during the test. Soil was collected for measurement after 25 days of the test.

[0096] Table 1 shows the basic chemical properties of the soil after adding different acidic soil conditioners in the pot experiment.

[0097]

[0098]

[0099] As can be seen from Table 1, after the acidic soil conditioner of the present invention is applied to the soil, the soil nutrients change between different treatments. Compared with the unconditioned acidic soil, the soil pH value can be significantly increased with the addition of the conditioner. The addition of the acidic soil conditioner significantly reduces the total amount of exchangeable acid in the soil. After the acidic soil conditioner is added, the content of alkaline nitrogen, available phosphorus and available potassium in the soil shows an increasing trend. The values ​​of each embodiment have a significant increase, while the value of the control example has no obvious increase, thereby proving that the acidic soil conditioner of the present invention can solve the problems of soil acidification and nutrient deficiency.

[0100] Test Example 2

[0101] The field test started in Ciwu Town, Zhuji City, Shaoxing City, Zhejiang Province (120°12′6″E, 29°53′15″N). There were no previous season crops and the soil type was red soil. The area is a typical subtropical monsoon climate zone with an average annual temperature of 16.3°C and an average annual precipitation of about 1373.6 mm. The field test began preparation and land preparation in mid-June, and nitrogen, phosphorus and potassium, organic fertilizers and corn seeds were purchased, and soil conditioners were prepared. Land preparation was carried out one week before sowing corn. After land preparation, the conditioner was evenly applied to the plowed soil and mixed evenly, and then the plow layer was leveled. Control Example 3 did not apply any soil conditioner.

[0102] Table 2 shows the basic chemical properties of soil after adding different acidic soil conditioners in the field test

[0103]

[0104] From the analysis in Table 2, it can be seen that after the acidic soil conditioners in Examples 1 to 3 were applied to the field, the soil pH value was significantly increased and the soil available nutrient content was increased, thereby proving that the acidic soil conditioner of the present invention can solve the problems of soil acidification and nutrient deficiency.

[0105] In summary, the acidic soil conditioner of the present invention can quickly increase the soil pH value, improve soil acidity, reduce the exchangeable acid content of soil, and weaken the toxic effect of soil active aluminum on plants by using a carbon-based acid conditioner, a mineral source conditioner and a microbial preparation in combination. The addition of the microbial preparation can also improve the vitality of crop roots, improve the stress resistance and disease and pest resistance of crops, promote the activity of soil microorganisms, promote the release of soil fast-acting nutrients, improve soil nutrients, and significantly improve the stability, air permeability and water permeability of soil structure, increase the activity of soil microorganisms, promote the release of fast-acting nutrients, improve the antibacterial and antibacterial properties of crops, and have strong nitrogen fixation, phosphorus fixation and potassium solubility functions, effectively enhance plant photosynthesis, promote soil microbial reproduction, and can greatly increase crop yields, thereby solving the problems of soil acidification and nutrient deficiency at the same time, and has the advantages of low cost, good acidification and fertilization effect, long duration, increased crop yields, and environmental protection and greenness, and has the value of promotion and application in the field of soil improvement technology.

[0106] The above embodiments are only preferred embodiments for fully illustrating the present invention, and the protection scope of the present invention is not limited thereto. Any equivalent substitution or change made by a person skilled in the art based on the present invention is within the protection scope of the present invention.

Claims

1. An acidic soil conditioner, characterized in that: The composition comprises, by weight: 30 to 70 parts of a carbon-based acidifier, 20 to 40 parts of a mineral-based conditioner, and 10 to 20 parts of a microbial preparation; The carbon-based acid regulator comprises, by weight: 10 to 20 parts of modified biochar, 40 to 50 parts of quicklime and 30 to 40 parts of oyster shell powder; The modified biochar is obtained by modifying rice husk biochar with calcium phosphate, potassium phosphate and magnesium chloride; The acidic soil conditioner is a coated acidic soil conditioner, and the coating amount of the coated acidic soil conditioner is 1-3%; The preparation method of the coated acidic soil conditioner specifically comprises: mixing 420g-450g of polyethylene glycol-400, 80g-100g of glycerol and 12g-15g of concentrated sulfuric acid and heating to 170°C, then adding 100g-130g of a mixture of humic acid, alginic acid and chitosan; continuing the liquefaction reaction for 90 minutes and then cooling to room temperature to obtain a liquefied liquid; the mass ratio of humic acid, alginic acid and chitosan in the mixture is 2:1:1; 1 kg of a granulated conditioner made by mixing carbon-based acid conditioner, mineral source conditioner and microbial preparation is heated to 75°C for 10-20 minutes, and then the liquefied liquid and isocyanate are evenly mixed in a mass ratio of 1:1, and then slowly dripped onto the surface of the conditioner to form a coating layer on the surface of the conditioner. The curing reaction is carried out for 15 minutes to obtain a coated acidic soil conditioner.

2. The acidic soil conditioner according to claim 1, characterized in that The mineral source conditioning agent is selected from at least one of attapulgite, montmorillonite and dolomite.

3. The acidic soil conditioner according to claim 2, characterized in that: The microbial preparation is selected from Bacillus subtilis, Bacillus licheniformis and Trichoderma harzianum.

4. A method for preparing the acidic soil conditioner according to claim 3, characterized in that: The following steps are involved: Preparation of carbon-based acid regulator: calcining and grinding oyster shells to obtain oyster shell powder; mixing oyster shell powder, modified biochar and quicklime in proportion to obtain an acid regulator; Preparation of the mineral source conditioning agent: at least one of attapulgite, montmorillonite and dolomite is crushed and sieved to obtain the mineral source conditioning agent; Preparation of the microbial preparation: Bacillus subtilis, Bacillus licheniformis and Trichoderma harzianum are mixed according to a proportion to obtain the microbial preparation; Preparation of acidic soil conditioner: the prepared carbon-based acid conditioner, mineral source conditioner and microbial preparation are mixed and granulated, and then coated to obtain coated acidic soil conditioner.

5. The method for preparing the acidic soil conditioner according to claim 4, characterized in that: The oyster shell is calcined at a temperature of 500° C. to 700° C. for a time of 2 h to 3 h. And / or, the modified biochar is prepared by: taking rice husk biochar, adding calcium phosphate, potassium phosphate and magnesium chloride to prepare a suspension, stirring and shaking the suspension for 24 hours, filtering, and drying at a temperature of 100° C.; and then carbonizing in a nitrogen environment at a temperature of 600° C. for 60 minutes to obtain the modified biochar; And / or, the dolomite is selected from natural dolomite with CaO>30%, MgO>15%, and SiO2>10%, and the particle size of the natural dolomite after crushing and sieving is less than 0.15 mm.

6. Use of the acidic soil conditioner according to any one of claims 1 to 3, characterized in that: The acidic soil conditioner is used for conditioning, improving and repairing degraded acidic soil.

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